iOS奇技淫巧總結(一)
作者：雜霧無塵
連結：http://www.jianshu.com/p/9fcd37c0ea05
來源：簡書
著作權歸作者所有。商業轉載請聯絡作者獲得授權，非商業轉載請註明出處。
1、禁止手機睡眠[UIApplication sharedApplication].idleTimerDisabled = YES;
2、隱藏某行cell
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
// 如果是你需要隱藏的那一行，返回高度為0
if(indexPath.row == YouWantToHideRow) {
return 0;
}
return 44;
}
// 然後再你需要隱藏cell的時候呼叫
[self.tableView beginUpdates];
[self.tableView endUpdates];
3、禁用button高亮
button.adjustsImageWhenHighlighted = NO;
或者在建立的時候
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
4、tableview遇到這種報錯failed to obtain a cell from its dataSource
是因為你的cell被呼叫的早了。先迴圈使用了cell，後又建立cell。順序錯了
可能原因：
1、xib的cell沒有註冊
2、記憶體中已經有這個cell的快取了(也就是說通過你的cellId找到的cell並不是你想要的型別)，這時候需要改下cell的標識
5、cocoa pods報這個錯誤：unable to access 'https://github.com/facebook/pop.git/': Operation timed out after 0 milliseconds with 0 out of 0 bytes received
解決辦法：原因可能是網路問題，網路請求超時了，只需要重試就行了
6、cocoa pods 出現ERROR: While executing gem ... (Errno::EPERM)
解決辦法：
https://segmentfault.com/q/1010000002926243
7、動畫切換window的根控制器
// options是動畫選項
[UIView transitionWithView:[UIApplication sharedApplication].keyWindow duration:0.5f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{
BOOL oldState = [UIView areAnimationsEnabled];
[UIView setAnimationsEnabled:NO];
[UIApplication sharedApplication].keyWindow.rootViewController = [RootViewController new];
[UIView setAnimationsEnabled:oldState];
} completion:^(BOOL finished) {
}];
8、去除陣列中重複的物件
NSArray *newArr = [oldArr valueForKeyPath:@“@distinctUnionOfObjects.self"];
9、編譯的時候遇到 no such file or directory: ／users／apple／XXX
是因為編譯的時候，在此路徑下找不到這個檔案，解決這個問題，首先是是要檢查缺少的檔案是不是在工程中，如果不在工程中，需要從本地拖進去，如果發現已經存在工程中了，或者拖進去還是報錯，這時候需要去build phases中搜尋這個檔案，這時候很可能會搜出現兩個相同的檔案，這時候，有一個路徑是正確的，刪除另外一個即可。如果刪除了還是不行，需要把兩個都刪掉，然後重新往工程裡拖進這個檔案即可
圖片.png
10、iOS8系統中，tableView最好實現下-tableView: heightForRowAtIndexPath:這個代理方法，要不然在iOS8中可能就會出現顯示不全或者無法響應事件的問題
11、iOS8中實現側滑功能的時候這個方法必須實現，要不然在iOS8中無法側滑
// 必須寫的方法，和editActionsForRowAtIndexPath配對使用，裡面什麼不寫也行
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
}
12、三個通知
NSSystemTimeZoneDidChangeNotification監聽修改時間介面的兩個按鈕狀態變化
UIApplicationSignificantTimeChangeNotification 監聽使用者改變時間 （只要點選自動設定按鈕就會呼叫）
NSSystemClockDidChangeNotification 監聽使用者修改時間（時間不同才會呼叫）
13、SDWebImage本地快取有時候會害人。如果之前快取過一張圖片，即使下次伺服器換了這張圖片，但是圖片url沒換，用sdwebimage下載下來的還是以前那張,所以遇到這種問題，不要先去懟伺服器，清空下快取再試就好了。
14、上線前注意：
1）刪掉程式碼中所有的測試程式碼
2）如果後臺有稽核模式，提醒後臺開啟此模式
3）主流程再跑一跑
4）全域性搜尋waring，檢查所有標記waring的地方
15、跳進app許可權設定
// 跳進app設定
if (UIApplicationOpenSettingsURLString != NULL) {
UIApplication *application = [UIApplication sharedApplication];
NSURL *URL = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
[application openURL:URL options:@{} completionHandler:nil];
} else {
[application openURL:URL];
}
}
16、給一個view截圖
UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
17、開發中如果要動態修改tableView的tableHeaderView或者tableFooterView的高度，需要給tableView重新設定，而不是直接更改高度。正確的做法是重新設定一下tableView.tableFooterView = 更改過高度的view。為什麼？其實在iOS8以上直接改高度是沒有問題的，在iOS8中出現了contentSize不準確的問題，這是解決辦法。
18、注意物件為nil的時候，呼叫此物件分類的方法不會執行
19、collectionView的內容小於其寬高的時候是不能滾動的，設定可以滾動：
collectionView.alwaysBounceHorizontal = YES;
collectionView.alwaysBounceVertical = YES;
20、設定navigationBar上的title顏色和大小
[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]
21、顏色轉圖片
+ (UIImage *)cl_imageWithColor:(UIColor *)color {
CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, rect);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
22、view設定圓角
#define ViewBorderRadius(View, Radius, Width, Color)\
\
[View.layer setCornerRadius:(Radius)];\
[View.layer setMasksToBounds:YES];\
[View.layer setBorderWidth:(Width)];\
[View.layer setBorderColor:[Color CGColor]] // view圓角
23、強／弱引用
#define WeakSelf(type) __weak typeof(type) weak##type = type; // weak
#define StrongSelf(type) __strong typeof(type) type = weak##type; // strong
24、由角度轉換弧度
#define DegreesToRadian(x) (M_PI * (x) / 180.0)
25、由弧度轉換角度
#define RadianToDegrees(radian) (radian*180.0)/(M_PI)
26、獲取圖片資源
#define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]]
27、獲取temp
#define PathTemp NSTemporaryDirectory()
28、獲取沙盒 Document
#define PathDocument [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject]
29、獲取沙盒 Cache
#define PathCache [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject]
30、GCD程式碼只執行一次
#define kDISPATCH_ONCE_BLOCK(onceBlock) static dispatch_once_t onceToken; dispatch_once(&onceToken, onceBlock);
31、自定義NSLog
#ifdef DEBUG
#define NSLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#else
#define NSLog(...)
#endif
32、Font
#define FontL(s) [UIFont systemFontOfSize:s weight:UIFontWeightLight]
#define FontR(s) [UIFont systemFontOfSize:s weight:UIFontWeightRegular]
#define FontB(s) [UIFont systemFontOfSize:s weight:UIFontWeightBold]
#define FontT(s) [UIFont systemFontOfSize:s weight:UIFontWeightThin]
#define Font(s) FontL(s)
33、FORMAT
#define FORMAT(f, ...) [NSString stringWithFormat:f, ## __VA_ARGS__]
34、在主執行緒上執行
#define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock);
35、開啟非同步執行緒
#define kDISPATCH_GLOBAL_QUEUE_DEFAULT(globalQueueBlock) dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), globalQueueBlocl);
36、通知
#define NOTIF_ADD(n, f) [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil]
#define NOTIF_POST(n, o) [[NSNotificationCenter defaultCenter] postNotificationName:n object:o]
#define NOTIF_REMV() [[NSNotificationCenter defaultCenter] removeObserver:self]
37、隨機顏色
+ (UIColor *)RandomColor {
NSInteger aRedValue = arc4random() % 255;
NSInteger aGreenValue = arc4random() % 255;
NSInteger aBlueValue = arc4random() % 255;
UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f green:aGreenValue / 255.0f blue:aBlueValue / 255.0f alpha:1.0f];
return randColor;
}
38、獲取window
+(UIWindow*)getWindow {
UIWindow* win = nil; //[UIApplication sharedApplication].keyWindow;
for (id item in [UIApplication sharedApplication].windows) {
if ([item class] == [UIWindow class]) {
if (!((UIWindow*)item).hidden) {
win = item;
break;
}
}
}
return win;
}
39、修改textField的placeholder的字型顏色、大小
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];
40、統一收起鍵盤
[[[UIApplication sharedApplication] keyWindow] endEditing:YES];
41、控制螢幕旋轉，在控制器中寫
/** 是否支援自動旋轉螢幕 */
- (BOOL)shouldAutorotate {
return YES;
}
/** 支援哪些螢幕方向 */
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight;
}
/** 預設的螢幕方向（當前ViewController必須是通過模態出來的UIViewController（模態帶導航的無效）方式展現出來的，才會呼叫這個方法） */
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight;
}
42、獲取app快取大小
- (CGFloat)getCachSize {
NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize];
//獲取自定義快取大小
//用列舉器遍歷 一個資料夾的內容
//1.獲取 資料夾列舉器
NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath];
__block NSUInteger count = 0;
//2.遍歷
for (NSString *fileName in enumerator) {
NSString *path = [myCachePath stringByAppendingPathComponent:fileName];
NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];
count += fileDict.fileSize;//自定義所有快取大小
}
// 得到是位元組 轉化為M
CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024;
return totalSize;
}
43、清理app快取
- (void)handleClearView {
//刪除兩部分
//1.刪除 sd 圖片快取
//先清除記憶體中的圖片快取
[[SDImageCache sharedImageCache] clearMemory];
//清除磁碟的快取
[[SDImageCache sharedImageCache] clearDisk];
//2.刪除自己快取
NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
[[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];
}
44、模型轉字典
static NSSet *classes;
- (NSMutableDictionary *)getParameterDictionary {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
Class c = self.class;
while (c) {
unsigned count;
objc_property_t *properties = class_copyPropertyList([c class], &count);
for (int i = 0; i < count; i++) {
NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];
dict[key] = [self valueForKey:key];
}
free(properties);
// 獲得父類
c = class_getSuperclass(c);
if ([self isClassFromFoundation:c]) break;
}
return dict;
}
- (BOOL)isClassFromFoundation:(Class)c
{
if (c == [NSObject class] || c == [NSManagedObject class]) return YES;
__block BOOL result = NO;
[[self foundationClasses] enumerateObjectsUsingBlock:^(Class foundationClass, BOOL *stop) {
if ([c isSubclassOfClass:foundationClass]) {
result = YES;
*stop = YES;
}
}];
return result;
}
- (NSSet *)foundationClasses
{
if (classes == nil) {
// 集合中沒有NSObject，因為幾乎所有的類都是繼承自NSObject，具體是不是NSObject需要特殊判斷
classes = [NSSet setWithObjects:
[NSURL class],
[NSDate class],
[NSValue class],
[NSData class],
[NSError class],
[NSArray class],
[NSDictionary class],
[NSString class],
[NSAttributedString class], nil];
}
return classes;
}
45、交換兩個方法實現
Class aClass = [self class];
SEL originalSelector = @selector(viewWillAppear:);
SEL swizzledSelector = @selector(xxx_viewWillAppear:);
Method originalMethod = class_getInstanceMethod(aClass, originalSelector);
Method swizzledMethod = class_getInstanceMethod(aClass, swizzledSelector);
BOOL didAddMethod =
class_addMethod(aClass,
originalSelector,
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(aClass,
swizzledSelector,
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
} else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
46、列印百分號和引號
NSLog(@"%%");
NSLog(@"\"");
47、幾個常用許可權判斷
if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) {
NSLog(@"沒有定位許可權");
}
AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if (statusVideo == AVAuthorizationStatusDenied) {
NSLog(@"沒有攝像頭許可權");
}
//是否有麥克風許可權
AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio];
if (statusAudio == AVAuthorizationStatusDenied) {
NSLog(@"沒有錄音許可權");
}
[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
if (status == PHAuthorizationStatusDenied) {
NSLog(@"沒有相簿許可權");
}
}];
48、獲取手機型號
+ (NSString *)getDeviceInfo {
struct utsname systemInfo;
uname(&systemInfo);
NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding];
if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone 2G";
if ([platform isEqualToString:@"iPhone1,2"]) return @"iPhone 3G";
if ([platform isEqualToString:@"iPhone2,1"]) return @"iPhone 3GS";
if ([platform isEqualToString:@"iPhone3,1"]) return @"iPhone 4";
if ([platform isEqualToString:@"iPhone3,2"]) return @"iPhone 4";
if ([platform isEqualToString:@"iPhone3,3"]) return @"iPhone 4";
if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone 4S";
if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone 5";
if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone 5";
if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone 5c";
if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone 5c";
if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone 5s";
if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone 5s";
if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone 6 Plus";
if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone 6";
if ([platform isEqualToString:@"iPhone8,1"]) return @"iPhone 6s";
if ([platform isEqualToString:@"iPhone8,2"]) return @"iPhone 6s Plus";
// 日行兩款手機型號均為日本獨佔，可能使用索尼FeliCa支付方案而不是蘋果支付
if ([platform isEqualToString:@"iPhone9,1"]) return @"國行、日版、港行iPhone 7";
if ([platform isEqualToString:@"iPhone9,2"]) return @"港行、國行iPhone 7 Plus";
if ([platform isEqualToString:@"iPhone9,3"]) return @"美版、臺版iPhone 7";
if ([platform isEqualToString:@"iPhone9,4"]) return @"美版、臺版iPhone 7 Plus";
if ([platform isEqualToString:@"iPhone8,4"]) return @"iPhone SE";
if ([platform isEqualToString:@"iPod1,1"]) return @"iPod Touch 1G";
if ([platform isEqualToString:@"iPod2,1"]) return @"iPod Touch 2G";
if ([platform isEqualToString:@"iPod3,1"]) return @"iPod Touch 3G";
if ([platform isEqualToString:@"iPod4,1"]) return @"iPod Touch 4G";
if ([platform isEqualToString:@"iPod5,1"]) return @"iPod Touch 5G";
if ([platform isEqualToString:@"iPad1,1"]) return @"iPad 1G";
if ([platform isEqualToString:@"iPad2,1"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,2"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,3"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,4"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad3,1"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,2"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,3"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,4"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad3,5"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad3,6"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,3"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"iPad4,6"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"i386"]) return @"iPhone Simulator";
if ([platform isEqualToString:@"x86_64"]) return @"iPhone Simulator";
return platform;
}
49、長按複製功能
- (void)viewDidLoad
{
[self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]];
}
- (void)pasteBoard:(UILongPressGestureRecognizer *)longPress {
if (longPress.state == UIGestureRecognizerStateBegan) {
UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
pasteboard.string = @"需要複製的文字";
}
}
50、cocoapods升級
在終端執行 sudo gem install -n / usr / local / bin cocoapods --pre
51、設定啟動頁後，依然顯示之前的
刪除app，手機重啟，重新安裝
52、判斷圖片型別
//通過圖片Data資料第一個位元組 來獲取圖片副檔名
- (NSString *)contentTypeForImageData:(NSData *)data
{
uint8_t c;
[data getBytes:&c length:1];
switch (c)
{
case 0xFF:
return @"jpeg";
case 0x89:
return @"png";
case 0x47:
return @"gif";
case 0x49:
case 0x4D:
return @"tiff";
case 0x52:
if ([data length] < 12) {
return nil;
}
NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];
if ([testString hasPrefix:@"RIFF"]
&& [testString hasSuffix:@"WEBP"])
{
return @"webp";
}
return nil;
}
return nil;
}
53、獲取手機和app資訊
NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];
CFShow(infoDictionary);
// app名稱
NSString *app_Name = [infoDictionary objectForKey:@"CFBundleDisplayName"];
// app版本
NSString *app_Version = [infoDictionary objectForKey:@"CFBundleShortVersionString"];
// app build版本
NSString *app_build = [infoDictionary objectForKey:@"CFBundleVersion"];
//手機序列號
NSString* identifierNumber = [[UIDevice currentDevice] uniqueIdentifier];
NSLog(@"手機序列號: %@",identifierNumber);
//手機別名： 使用者定義的名稱
NSString* userPhoneName = [[UIDevice currentDevice] name];
NSLog(@"手機別名: %@", userPhoneName);
//裝置名稱
NSString* deviceName = [[UIDevice currentDevice] systemName];
NSLog(@"裝置名稱: %@",deviceName );
//手機系統版本
NSString* phoneVersion = [[UIDevice currentDevice] systemVersion];
NSLog(@"手機系統版本: %@", phoneVersion);
//手機型號
NSString* phoneModel = [[UIDevice currentDevice] model];
NSLog(@"手機型號: %@",phoneModel );
//地方型號 （國際化區域名稱）
NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel];
NSLog(@"國際化區域名稱: %@",localPhoneModel );
NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];
// 當前應用名稱
NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"];
NSLog(@"當前應用名稱：%@",appCurName);
// 當前應用軟體版本 比如：1.0.1
NSString *appCurVersion = [infoDictionary objectForKey:@"CFBundleShortVersionString"];
NSLog(@"當前應用軟體版本:%@",appCurVersion);
// 當前應用版本號碼 int型別
NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"];
NSLog(@"當前應用版本號碼：%@",appCurVersionNum);
54、獲取一個類的所有屬性
id LenderClass = objc_getClass("Lender");
unsigned int outCount, i;
objc_property_t *properties = class_copyPropertyList(LenderClass, &outCount);
for (i = 0; i < outCount; i++) {
objc_property_t property = properties[i];
fprintf(stdout, "%s %s\n", property_getName(property), property_getAttributes(property));
}
55、image圓角
- (UIImage *)circleImage
{
// NO代表透明
UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);
// 獲得上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
// 新增一個圓
CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
// 方形變圓形
CGContextAddEllipseInRect(ctx, rect);
// 裁剪
CGContextClip(ctx);
// 將圖片畫上去
[self drawInRect:rect];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
56、image拉伸
+ (UIImage *)resizableImage:(NSString *)imageName
{
UIImage *image = [UIImage imageNamed:imageName];
CGFloat imageW = image.size.width;
CGFloat imageH = image.size.height;
return [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5, imageW * 0.5) resizingMode:UIImageResizingModeStretch];
}
57、JSON字串轉字典
+ (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString {
NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];
return responseJSON;
}
58、身份證號驗證
- (BOOL)validateIdentityCard {
BOOL flag;
if (self.length <= 0) {
flag = NO;
return flag;
}
NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";
NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
return [identityCardPredicate evaluateWithObject:self];
}
59、獲取裝置mac地址
+ (NSString *)macAddress {
int mib[6];
size_t len;
char *buf;
unsigned char *ptr;
struct if_msghdr *ifm;
struct sockaddr_dl *sdl;
mib[0] = CTL_NET;
mib[1] = AF_ROUTE;
mib[2] = 0;
mib[3] = AF_LINK;
mib[4] = NET_RT_IFLIST;
if((mib[5] = if_nametoindex("en0")) == 0) {
printf("Error: if_nametoindex error\n");
return NULL;
}
if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
printf("Error: sysctl, take 1\n");
return NULL;
}
if((buf = malloc(len)) == NULL) {
printf("Could not allocate memory. Rrror!\n");
return NULL;
}
if(sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
printf("Error: sysctl, take 2");
return NULL;
}
ifm = (struct if_msghdr *)buf;
sdl = (struct sockaddr_dl *)(ifm + 1);
ptr = (unsigned char *)LLADDR(sdl);
NSString *outstring = [NSString stringWithFormat:@"%02X:%02X:%02X:%02X:%02X:%02X",
*ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];
free(buf);
return outstring;
}
60、匯入自定義字型庫
1、找到你想用的字型的 ttf 格式，拖入工程
2、在工程的plist中增加一行陣列，“Fonts provided by application”
3、為這個key新增一個item，value為你剛才匯入的ttf檔名
4、直接使用即可：label.font = [UIFont fontWithName:@"你剛才匯入的ttf檔名" size:20.0]；
61、拿到當前正在顯示的控制器，不管是push進去的，還是present進去的都能拿到
- (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc {
if ([vc isKindOfClass:[UINavigationController class]]) {
return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]];
}else if ([vc isKindOfClass:[UITabBarController class]]){
return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]];
} else {
if (vc.presentedViewController) {
return [self getVisibleViewControllerFrom:vc.presentedViewController];
} else {
return vc;
}
}
}
62、runtime為一個類動態新增屬性
// 動態新增屬性的本質是: 讓物件的某個屬性與值產生關聯
objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
63、獲取runtime為一個類動態新增的屬性
objc_getAssociatedObject(self, WZBPlaceholderViewKey);
64、KVO監聽某個物件的屬性
// 新增監聽者
[self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil];
// 當監聽的屬性值變化的時候會來到這個方法
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqualToString:@"property"]) {
[self textViewTextChange];
} else {
}
}
65、Reachability判斷網路狀態
NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus];
if (status == NotReachable) {
NSLog(@"當前裝置無網路");
}
if (status == ReachableViaWiFi) {
NSLog(@"當前wifi網路");
}
if (status == ReachableViaWWAN) {
NSLog(@"當前蜂窩行動網路");
}
66、AFNetworking監聽網路狀態
// 監聽網路狀況
AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager];
[mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
switch (status) {
case AFNetworkReachabilityStatusUnknown:
break;
case AFNetworkReachabilityStatusNotReachable: {
[SVProgressHUD showInfoWithStatus:@"當前裝置無網路"];
}
break;
case AFNetworkReachabilityStatusReachableViaWiFi:
[SVProgressHUD showInfoWithStatus:@"當前Wi-Fi網路"];
break;
case AFNetworkReachabilityStatusReachableViaWWAN:
[SVProgressHUD showInfoWithStatus:@"當前蜂窩行動網路"];
break;
default:
break;
}
}];
[mgr startMonitoring];
67、透明顏色不影響子檢視透明度
[UIColor colorWithRed:<#(CGFloat)#> green:<#(CGFloat)#> blue:<#(CGFloat)#> alpha:<#(CGFloat)#>];
68、取圖片某一點的顏色
if (point.x < 0 || point.y < 0) return nil;
CGImageRef imageRef = self.CGImage;
NSUInteger width = CGImageGetWidth(imageRef);
NSUInteger height = CGImageGetHeight(imageRef);
if (point.x >= width || point.y >= height) return nil;
unsigned char *rawData = malloc(height * width * 4);
if (!rawData) return nil;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(rawData,
width,
height,
bitsPerComponent,
bytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedLast
| kCGBitmapByteOrder32Big);
if (!context) {
free(rawData);
return nil;
}
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CGContextRelease(context);
int byteIndex = (bytesPerRow * point.y) + point.x * bytesPerPixel;
CGFloat red = (rawData[byteIndex] * 1.0) / 255.0;
CGFloat green = (rawData[byteIndex + 1] * 1.0) / 255.0;
CGFloat blue = (rawData[byteIndex + 2] * 1.0) / 255.0;
CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.0;
UIColor *result = nil;
result = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
free(rawData);
return result;
69、判斷該圖片是否有透明度通道
- (BOOL)hasAlphaChannel
{
CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage);
return (alpha == kCGImageAlphaFirst ||
alpha == kCGImageAlphaLast ||
alpha == kCGImageAlphaPremultipliedFirst ||
alpha == kCGImageAlphaPremultipliedLast);
}
70、獲得灰度圖
+ (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage
{
int width = sourceImage.size.width;
int height = sourceImage.size.height;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);
CGColorSpaceRelease(colorSpace);
if (context == NULL) {
return nil;
}
CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);
CGImageRef contextRef = CGBitmapContextCreateImage(context);
UIImage *grayImage = [UIImage imageWithCGImage:contextRef];
CGContextRelease(context);
CGImageRelease(contextRef);
return grayImage;
}
71、根據bundle中的檔名讀取圖片
+ (UIImage *)imageWithFileName:(NSString *)name {
NSString *extension = @"png";
NSArray *components = [name componentsSeparatedByString:@"."];
if ([components count] >= 2) {
NSUInteger lastIndex = components.count - 1;
extension = [components objectAtIndex:lastIndex];
name = [name substringToIndex:(name.length-(extension.length+1))];
}
// 如果為Retina螢幕且存在對應圖片，則返回Retina圖片，否則查詢普通圖片
if ([UIScreen mainScreen].scale == 2.0) {
name = [name stringByAppendingString:@"@2x"];
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
if (path != nil) {
return [UIImage imageWithContentsOfFile:path];
}
}
if ([UIScreen mainScreen].scale == 3.0) {
name = [name stringByAppendingString:@"@3x"];
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
if (path != nil) {
return [UIImage imageWithContentsOfFile:path];
}
}
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
if (path) {
return [UIImage imageWithContentsOfFile:path];
}
return nil;
}
72、合併兩個圖片
+ (UIImage*)mergeImage:(UIImage*)firstImage withImage:(UIImage*)secondImage {
CGImageRef firstImageRef = firstImage.CGImage;
CGFloat firstWidth = CGImageGetWidth(firstImageRef);
CGFloat firstHeight = CGImageGetHeight(firstImageRef);
CGImageRef secondImageRef = secondImage.CGImage;
CGFloat secondWidth = CGImageGetWidth(secondImageRef);
CGFloat secondHeight = CGImageGetHeight(secondImageRef);
CGSize mergedSize = CGSizeMake(MAX(firstWidth, secondWidth), MAX(firstHeight, secondHeight));
UIGraphicsBeginImageContext(mergedSize);
[firstImage drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)];
[secondImage drawInRect:CGRectMake(0, 0, secondWidth, secondHeight)];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
73、根據bundle中的圖片名建立imageview
+ (id)imageViewWithImageNamed:(NSString*)imageName
{
return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
}
74、為imageView新增倒影
CGRect frame = self.frame;
frame.origin.y += (frame.size.height + 1);
UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame];
self.clipsToBounds = TRUE;
reflectionImageView.contentMode = self.contentMode;
[reflectionImageView setImage:self.image];
reflectionImageView.transform = CGAffineTransformMakeScale(1.0, -1.0);
CALayer *reflectionLayer = [reflectionImageView layer];
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.bounds = reflectionLayer.bounds;
gradientLayer.position = CGPointMake(reflectionLayer.bounds.size.width / 2, reflectionLayer.bounds.size.height * 0.5);
gradientLayer.colors = [NSArray arrayWithObjects:
(id)[[UIColor clearColor] CGColor],
(id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil];
gradientLayer.startPoint = CGPointMake(0.5,0.5);
gradientLayer.endPoint = CGPointMake(0.5,1.0);
reflectionLayer.mask = gradientLayer;
[self.superview addSubview:reflectionImageView];
75、畫水印
// 畫水印
- (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect
{
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)
{
UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0);
}
//原圖
[image drawInRect:self.bounds];
//水印圖
[mark drawInRect:rect];
UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self.image = newPic;
}
76、讓label的文字內容顯示在左上／右上／左下／右下／中心頂／中心底部
自定義UILabel
// 重寫label的textRectForBounds方法
- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {
CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];
switch (self.textAlignmentType) {
case WZBTextAlignmentTypeLeftTop: {
rect.origin = bounds.origin;
}
break;
case WZBTextAlignmentTypeRightTop: {
rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y);
}
break;
case WZBTextAlignmentTypeLeftBottom: {
rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height);
}
break;
case WZBTextAlignmentTypeRightBottom: {
rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height);
}
break;
case WZBTextAlignmentTypeTopCenter: {
rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y);
}
break;
case WZBTextAlignmentTypeBottomCenter: {
rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height);
}
break;
case WZBTextAlignmentTypeLeft: {
rect.origin = CGPointMake(0, rect.origin.y);
}
break;
case WZBTextAlignmentTypeRight: {
rect.origin = CGPointMake(rect.origin.x, 0);
}
break;
case WZBTextAlignmentTypeCenter: {
rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2);
}
break;
default:
break;
}
return rect;
}
- (void)drawTextInRect:(CGRect)rect {
CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines];
[super drawTextInRect:textRect];
}
77、scrollView上的輸入框，鍵盤擋住的問題
推薦用IQKeyboardManager這個框架！
手動解決如下
1、監聽鍵盤彈出／消失的通知
2、在通知中加入程式碼：
NSDictionary* info = [aNotification userInfo];
CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view];
CGSize kbSize =keyPadFrame.size;
CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview];
CGRect aRect = self.view.bounds;
aRect.size.height -= (kbSize.height);
CGPoint origin = activeRect.origin;
origin.y -= backScrollView.contentOffset.y;
if (!CGRectContainsPoint(aRect, origin)) {
CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height));
[backScrollView setContentOffset:scrollPoint animated:YES];
}
78、frame佈局的cell動態高度
這種通常在你的模型中新增一個輔助屬性cellHeight，在模型中重寫這個屬性的get方法，根據你的佈局和模型中的其他屬性值計算出總高度。最後在tableView：heightForRow方法中，根據indexPath找出對應的模型，返回這個高度即可。
79、AutoLayout佈局的cell動態高度
1、設定tableView的屬性
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 44.0; // 這個屬性非0，估計cell高度
2、至上而下設定cell的約束，注意，上下左右最好都要頂到cell的四周
圖片.png
80、使用performSelector:呼叫函式，記憶體洩漏問題
當我們在開發中使用[obj performSelector:NSSelectorFromString(@"aMethod")];這類方法時可能會收到一個警告"performSelector may cause a leak because its selector is unknown".
是因為編譯器不清楚這個物件能不能相應這個方法，如果不能，則是不安全的，而且編譯器也不清楚該怎麼處理這個方法的返回值！
使用以下程式碼呼叫即可：
if (! obj) { return; }
SEL selector = NSSelectorFromString(@"aMethod");
IMP imp = [obj methodForSelector:selector];
void (*func)(id, SEL) = (void *)imp;
func(obj, selector);
或者：
SEL selector = NSSelectorFromString(@"aMethod");
((void (*)(id, SEL))[obj methodForSelector:selector])(obj, selector);
81、一個字串是否包含另一個字串
// 方法1
if ([str1 containsString:str2]) {
NSLog(@"str1包含str2");
} else {
NSLog(@"str1不包含str2");
}
// 方法2
if ([str1 rangeOfString: str2].location == NSNotFound) {
NSLog(@"str1不包含str2");
} else {
NSLog(@"str1包含str2");
}
82、cell去除選中效果
cell.selectionStyle = UITableViewCellSelectionStyleNone;
83、cell點按效果
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
84、當刪除一個從xib拖出來的屬性時，一定記得把xib中對應的線也刪掉，不然會報類似[<ViewController 0x7fea6ed05980> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key的crash
85、真機測試的時候報錯：Could not launch "你的 App"，process launch failed: Security
因為你的app沒有上線，iOS9開始，需要手動信任Xcode生成的描述檔案，開啟手機設定->通用->描述檔案->點選你的app的描述檔案->點選信任
86、真機測試的時候報錯：Could not find Developer Disk Image
這是因為你的裝置系統版本大於Xcode能相容的系統版本，比如你的裝置是iOS10.3，而Xcode版本是8.2（Xcode8.2最大相容iOS10.2），就會報這個錯誤。解決辦法就是升級Xcode！
87、UITextView沒有placeholder的問題？
網上有很多此類自定義控制元件，也可以參考下我寫的一個UITextView分類 UITextView-WZB
88、移除字串中的空格和換行
+ (NSString *)removeSpaceAndNewline:(NSString *)str {
NSString *temp = [str stringByReplacingOccurrencesOfString:@" " withString:@""];
temp = [temp stringByReplacingOccurrencesOfString:@"\r" withString:@""];
temp = [temp stringByReplacingOccurrencesOfString:@"\n" withString:@""];
return temp;
}
89、判斷字串中是否有空格
+ (BOOL)isBlank:(NSString *)str {
NSRange _range = [str rangeOfString:@" "];
if (_range.location != NSNotFound) {
//有空格
return YES;
} else {
//沒有空格
return NO;
}
}
90、獲取一個視訊的第一幀圖片
NSURL *url = [NSURL URLWithString:filepath];
AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url options:nil];
AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1];
generate1.appliesPreferredTrackTransform = YES;
NSError *err = NULL;
CMTime time = CMTimeMake(1, 2);
CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err];
UIImage *one = [[UIImage alloc] initWithCGImage:oneRef];
return one;
91、獲取視訊的時長
+ (NSInteger)getVideoTimeByUrlString:(NSString *)urlString {
NSURL *videoUrl = [NSURL URLWithString:urlString];
AVURLAsset *avUrl = [AVURLAsset assetWithURL:videoUrl];
CMTime time = [avUrl duration];
int seconds = ceil(time.value/time.timescale);
return seconds;
}
92、字串是否為空
+ (BOOL)isEqualToNil:(NSString *)str {
return str.length <= 0 || [str isEqualToString:@""] || !str;
}
93、將app上傳到App Store的時候通常會遇到這個問題
圖片.png
很多人說這事蘋果爸爸伺服器問題，重複嘗試幾次，總會成功的！
但是經過嘗試發現如果使用Application Loader上傳成功率就非常高，所以還是推薦把ipa檔案匯出直接用Application Loader上傳。
如果Application Loader也不行，需要檢查下自己的網路，有時候vpn也會提高速度。
94、當tableView佔不滿一屏時，去除下邊多餘的單元格
self.tableView.tableHeaderView = [UIView new];
self.tableView.tableFooterView = [UIView new];
95、isKindOfClass和isMemberOfClass的區別
isKindOfClass可以判斷某個物件是否屬於某個類，或者這個類的子類。
isMemberOfClass更加精準，它只能判斷這個物件型別是否為這個類(不能判斷子類)
96、__block
當一個區域性變數需要在block裡改變時，需要在定義時加上__block修飾，具體請看官方文件 http://developer.apple.com/library/ios/documentation/cocoa/Conceptual/Blocks/Articles/bxVariables.html#//apple_ref/doc/uid/TP40007502-CH6-SW6
97、-[ViewController aMethod:]: unrecognized selector sent to instance 0x7fe91e607fb0
這是一個經典錯誤，ViewController不能響應aMethod這個方法，錯誤原因可能viewController檔案中沒有實現aMethod這個方法
98、UITableView (<UITableView: 0x7ff19b027000; >) failed to obtain a cell from its dataSource (<ViewController: 0x7ff19a507520>)
這個錯誤原因是tableView的代理方法-tableView:cellForRowAtIndexPath:需要返回一個UITableViewCell,而你返回了一個nil。另外這個地方返回值不是UITableViewCell型別也會導致崩潰
99、約束如何做UIView動畫？
1、把需要改的約束Constraint拖條線出來，成為屬性
2、在需要動畫的地方加入程式碼，改變此屬性的constant屬性
3、開始做UIView動畫，動畫裡邊呼叫layoutIfNeeded方法
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint;
self.buttonTopConstraint.constant = 100;
[UIView animateWithDuration:.5 animations:^{
[self.view layoutIfNeeded];
}];
100、從NSURL中拿到連結字串
NSString *urlString = myURL.absoluteString;
101、將tableView滾動到頂部
[tableView setContentOffset:CGPointZero animated:YES];
或者
[tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];
102、如果用addTarget:action:forControlEvents:方法為一個button新增了很多點選事件，在某個時刻想一次刪除怎麼辦？只需要呼叫下邊這句程式碼
[youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents];
103、某個字型的高度
font.lineHeight;
104、刪除某個view所有的子檢視
[[someView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];
105、刪除NSUserDefaults所有記錄
//方法一
NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];
//方法二
- (void)resetDefaults {
NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
NSDictionary * dict = [defs dictionaryRepresentation];
for (id key in dict) {
[defs removeObjectForKey:key];
}
[defs synchronize];
}
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];
106、禁用系統滑動返回功能
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;
}
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;
}
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
return NO;
}
107、模擬器報錯
圖片.png
模擬器報錯 解決辦法：
開啟模擬器->Simulator->Reset Content and Settings...
如果不行，就重啟試試！
108、自定義cell選中背景顏色
UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor redColor];
[cell setSelectedBackgroundView:bgColorView];
109、UILabel設定內邊距
子類化UILabel，重寫drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect {
// 邊距，上左下右
UIEdgeInsets insets = {0, 5, 0, 5};
[super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}
110、UILabel設定文字描邊
子類化UILabel，重寫drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect
{
CGContextRef c = UIGraphicsGetCurrentContext();
// 設定描邊寬度
CGContextSetLineWidth(c, 1);
CGContextSetLineJoin(c, kCGLineJoinRound);
CGContextSetTextDrawingMode(c, kCGTextStroke);
// 描邊顏色
self.textColor = [UIColor redColor];
[super drawTextInRect:rect];
// 文字顏色
self.textColor = [UIColor yellowColor];
CGContextSetTextDrawingMode(c, kCGTextFill);
[super drawTextInRect:rect];
}
111、使用模擬器截圖
快捷鍵command + s
或者File->Save Screen Shot
112、scrollView滾動到最下邊
CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);
[scrollView setContentOffset:bottomOffset animated:YES];
113、UIView背景顏色漸變
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
[self.view addSubview:view];
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = view.bounds;
gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
[view.layer insertSublayer:gradient atIndex:0];
114、停止UIView動畫
[yourView.layer removeAllAnimations]
115、為UIView某個角新增圓角
// 左上角和右下角新增圓角
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = view.bounds;
maskLayer.path = maskPath.CGPath;
view.layer.mask = maskLayer;
116、刪除Xcode Derived data快取資料
依次點選Xcode -> Preferences -> location，然後點選 Derived data路徑後到小箭頭，刪除這個資料夾下的資料就可以了，如圖
圖片.png
117、將一個view放置在其兄弟檢視的最上面
[parentView bringSubviewToFront:yourView]
118、將一個view放置在其兄弟檢視的最下面
[parentView sendSubviewToBack:yourView]
119、讓手機震動一下
匯入框架
#import <AudioToolbox/AudioToolbox.h>
AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);
或者
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
120、layoutSubviews方法什麼時候呼叫？
1、init方法不會呼叫
2、addSubview方法等時候會呼叫
3、bounds改變的時候呼叫
4、scrollView滾動的時候會呼叫scrollView的layoutSubviews方法(所以不建議在scrollView的layoutSubviews方法中做複雜邏輯)
5、旋轉裝置的時候呼叫
6、子檢視被移除的時候呼叫
參考請看：http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/
121、讓UILabel在指定的地方換行
// 換行符為\n,在需要換行的地方加上這個符號即可，如
label.numberOfLines = 0;
label.text = @"此處\n換行";
122、搖一搖功能
1、開啟搖一搖功能
[UIApplication sharedApplication].applicationSupportsShakeToEdit = YES;
2、讓需要搖動的控制器成為第一響應者
[self becomeFirstResponder];
3、實現以下方法
// 開始搖動
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 取消搖動
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 搖動結束
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event
123、獲取圖片大小
CGFloat imageWidth = image.size.width;
CGFloat imageHeight = imageWidth * image.scale;
124、獲取view的座標在整個window上的位置
// v上的(0, 0)點在toView上的位置
CGPoint point = [v convertPoint:CGPointMake(0, 0) toView:[UIApplication sharedApplication].windows.lastObject];
或者
CGPoint point = [v.superview convertPoint:v.frame.origin toView:[UIApplication sharedApplication].windows.lastObject];
125、提交App Store稽核程式限制
您的應用程式的未壓縮大小必須小於4GB。每個Mach-O可執行檔案（例如app_name.app/app_name）不能超過這些限制：
對於MinimumOSVersion小於7.0的應用程式：TEXT二進位制檔案中所有部分的總數最多為80 MB 。
對於MinimumOSVersion7.x到8.x的應用程式：TEXT對於二進位制檔案中每個體系結構片段的每個片段，最大為60 MB 。
對於MinimumOSVersion9.0或更高版本的應用程式：__TEXT二進位制檔案中所有部分的總數最多為500 MB 。參閱：iTunes Connect開發者指南
126、修改UISegmentedControl的字型大小
[segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal];
127、在非ViewController的地方彈出UIAlertController對話方塊
// 最好抽成一個分類
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
//...
id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController;
if([rootViewController isKindOfClass:[UINavigationController class]])
{
rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject;
}
if([rootViewController isKindOfClass:[UITabBarController class]])
{
rootViewController = ((UITabBarController *)rootViewController).selectedViewController;
}
[rootViewController presentViewController:alertController animated:YES completion:nil];
128、獲取一個view所屬的控制器
// view分類方法
- (UIViewController *)belongViewController {
for (UIView *next = [self superview]; next; next = next.superview) {
UIResponder* nextResponder = [next nextResponder];
if ([nextResponder isKindOfClass:[UIViewController class]]) {
return (UIViewController *)nextResponder;
}
}
return nil;
}
129、UIImage和base64互轉
// view分類方法
- (NSString *)encodeToBase64String:(UIImage *)image {
return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}
- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
return [UIImage imageWithData:data];
}
130、UIWebView設定背景透明
[webView setBackgroundColor:[UIColor clearColor]];
[webView setOpaque:NO];
131、判斷NSDate是不是今天
NSDateComponents *otherDay = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate];
NSDateComponents *today = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:[NSDate date]];
if([today day] == [otherDay day] &&
[today month] == [otherDay month] &&
[today year] == [otherDay year] &&
[today era] == [otherDay era]) {
// 是今天
}
132、設定tableView分割線顏色
[self.tableView setSeparatorColor:[UIColor myColor]];
133、設定螢幕方向
NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
[[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];
[UIViewController attemptRotationToDeviceOrientation];
134、比較兩個顏色是否相等
- (BOOL)isEqualToColor:(UIColor *)otherColor {
CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();
UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) {
if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) {
const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);
CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};
CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components );
UIColor *color = [UIColor colorWithCGColor:colorRef];
CGColorRelease(colorRef);
return color;
} else
return color;
};
UIColor *selfColor = convertColorToRGBSpace(self);
otherColor = convertColorToRGBSpace(otherColor);
CGColorSpaceRelease(colorSpaceRGB);
return [selfColor isEqual:otherColor];
}
135、tableViewCell分割線頂到頭
(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
[cell setSeparatorInset:UIEdgeInsetsZero];
[cell setLayoutMargins:UIEdgeInsetsZero];
cell.preservesSuperviewLayoutMargins = NO;
}(void)viewDidLayoutSubviews {
[self.tableView setSeparatorInset:UIEdgeInsetsZero];
[self.tableView setLayoutMargins:UIEdgeInsetsZero];
}
136、不讓控制器的view隨著控制器的xib拉伸或壓縮
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
137、cocoaPods報錯 : [!] Unable to add a source with url https://github.com/CocoaPods/Specs.git named master-1.You can try adding it manually in ~/.cocoapods/repos or via pod repo add.
解決方法：這是因為電腦裡安裝了另外一個Xcode導致cocoapods找不到路徑了
在終端執行 sudo xcode-select -switch /Applications/Xcode.app 即可
138、安裝cocoapods的時候出現 ERROR: While executing gem ... (Errno::EPERM) Operation not permitted - /usr/bin/pod
解決辦法：直接在終端執行 sudo gem install -n /usr/local/bin cocoapods
139、在狀態列增加網路請求的菊花，類似safari載入網頁的時候狀態列菊花
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
140、檢查一個rect是否包含一個point
// point是否在rect內
BOOL isContains = CGRectContainsPoint(rect, point);
141、在指定的寬度下，讓UILabel自動設定最佳font
label.adjustsFontSizeToFitWidth = YES;
142、將一個image儲存在相簿中
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
或者
#import <Photos/Photos.h>
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetChangeRequest *changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
changeRequest.creationDate = [NSDate date];
} completionHandler:^(BOOL success, NSError *error) {
if (success) {
NSLog(@"successfully saved");
}
else {
NSLog(@"error saving to photos: %@", error);
}
}];
143、修改cell.imageView的大小
UIImage *icon = [UIImage imageNamed:@""];
CGSize itemSize = CGSizeMake(30, 30);
UIGraphicsBeginImageContextWithOptions(itemSize, NO ,0.0);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[icon drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
144、為一個view新增虛線邊框
CAShapeLayer *border = [CAShapeLayer layer];
border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor;
border.fillColor = nil;
border.lineDashPattern = @[@4, @2];
border.path = [UIBezierPath bezierPathWithRect:view.bounds].CGPath;
border.frame = view.bounds;
[view.layer addSublayer:border];
145、UITextView中開啟或禁用複製，剪下，選擇，全選等功能
// 繼承UITextView重寫這個方法
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
// 返回NO為禁用，YES為開啟
// 貼上
if (action == @selector(paste:)) return NO;
// 剪下
if (action == @selector(cut:)) return NO;
// 複製
if (action == @selector(copy:)) return NO;
// 選擇
if (action == @selector(select:)) return NO;
// 選中全部
if (action == @selector(selectAll:)) return NO;
// 刪除
if (action == @selector(delete:)) return NO;
// 分享
if (action == @selector(share)) return NO;
return [super canPerformAction:action withSender:sender];
}
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