RTL適配
www.cocoachina.com/ios/2018041…
UITableView的plain樣式下，取消區頭停滯效果
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloat sectionHeaderHeight = sectionHead.height;
if (scrollView.contentOffset.y=0)
{
scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
}
else if(scrollView.contentOffset.y>=sectionHeaderHeight)
{
scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0);
}
}
複製程式碼獲取某個view所在的控制器
- (UIViewController *)viewController
{
UIViewController *viewController = nil;
UIResponder *next = self.nextResponder;
while (next)
{
if ([next isKindOfClass:[UIViewController class]])
{
viewController = (UIViewController *)next;
break;
}
next = next.nextResponder;
}
return viewController;
}
複製程式碼兩種方法刪除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];
}
複製程式碼取圖片某一畫素點的顏色 在UIImage的分類中
- (UIColor *)colorAtPixel:(CGPoint)point
{
if (!CGRectContainsPoint(CGRectMake(0.0f, 0.0f, self.size.width, self.size.height), point))
{
return nil;
}
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
int bytesPerPixel = 4;
int bytesPerRow = bytesPerPixel * 1;
NSUInteger bitsPerComponent = 8;
unsigned char pixelData[4] = {0, 0, 0, 0};
CGContextRef context = CGBitmapContextCreate(pixelData,
1,
1,
bitsPerComponent,
bytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextSetBlendMode(context, kCGBlendModeCopy);
CGContextTranslateCTM(context, -point.x, point.y - self.size.height);
CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, self.size.width, self.size.height), self.CGImage);
CGContextRelease(context);
CGFloat red = (CGFloat)pixelData[0] / 255.0f;
CGFloat green = (CGFloat)pixelData[1] / 255.0f;
CGFloat blue = (CGFloat)pixelData[2] / 255.0f;
CGFloat alpha = (CGFloat)pixelData[3] / 255.0f;
return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}
複製程式碼字串反轉
第一種：
- (NSString *)reverseWordsInString:(NSString *)str
{
NSMutableString *newString = [[NSMutableString alloc] initWithCapacity:str.length];
for (NSInteger i = str.length - 1; i >= 0 ; i --)
{
unichar ch = [str characterAtIndex:i];
[newString appendFormat:@"%c", ch];
}
return newString;
}
//第二種：
- (NSString*)reverseWordsInString:(NSString*)str
{
NSMutableString *reverString = [NSMutableString stringWithCapacity:str.length];
[str enumerateSubstringsInRange:NSMakeRange(0, str.length) options:NSStringEnumerationReverse | NSStringEnumerationByComposedCharacterSequences usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
[reverString appendString:substring];
}];
return reverString;
}
複製程式碼禁止鎖屏
[UIApplication sharedApplication].idleTimerDisabled = YES;
或
[[UIApplication sharedApplication] setIdleTimerDisabled:YES];
複製程式碼iOS跳轉到App Store下載應用評分
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"]];
複製程式碼手動更改iOS狀態列的顏色
- (void)setStatusBarBackgroundColor:(UIColor *)color
{
UIView *statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"];
if ([statusBar respondsToSelector:@selector(setBackgroundColor:)])
{
statusBar.backgroundColor = color;
}
}
複製程式碼判斷當前ViewController是push還是present的方式顯示的
NSArray *viewcontrollers=self.navigationController.viewControllers;
if (viewcontrollers.count > 1)
{
if ([viewcontrollers objectAtIndex:viewcontrollers.count - 1] == self)
{
//push方式
[self.navigationController popViewControllerAnimated:YES];
}
}
else
{
//present方式
[self dismissViewControllerAnimated:YES completion:nil];
}
獲取實際使用的LaunchImage圖片
- (NSString *)getLaunchImageName
{
CGSize viewSize = self.window.bounds.size;
// 豎屏
NSString *viewOrientation = @"Portrait";
NSString *launchImageName = nil;
NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
for (NSDictionary* dict in imagesDict)
{
CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
{
launchImageName = dict[@"UILaunchImageName"];
}
}
return launchImageName;
}
複製程式碼iOS在當前螢幕獲取第一響應
UIWindow * keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView * firstResponder = [keyWindow performSelector:@selector(firstResponder)];
複製程式碼判斷view是不是指定檢視的子檢視
BOOL isView = [textView isDescendantOfView:self.view];
複製程式碼NSArray 快速求總和 最大值 最小值 和 平均值
NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];
CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];
CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];
複製程式碼修改UITextField中Placeholder的文字顏色
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
複製程式碼獲取一個類的所有子類
+ (NSArray *) allSubclasses
{
Class myClass = [self class];
NSMutableArray *mySubclasses = [NSMutableArray array];
unsigned int numOfClasses;
Class *classes = objc_copyClassList(&numOfClasses;);
for (unsigned int ci = 0; ci ( numOfClasses; ci++)
{
Class superClass = classes[ci];
do{
superClass = class_getSuperclass(superClass);
} while (superClass && superClass != myClass);
if (superClass)
{
[mySubclasses addObject: classes[ci]];
}
}
free(classes);
return mySubclasses;
}
複製程式碼阿拉伯數字轉中文格式
+(NSString *)translation:(NSString *)arebic
{
NSString *str = arebic;
NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"];
NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];
NSArray *digits = @[@"個",@"十",@"百",@"千",@"萬",@"十",@"百",@"千",@"億",@"十",@"百",@"千",@"兆"];
NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:chinese_numerals forKeys:arabic_numerals];
NSMutableArray *sums = [NSMutableArray array];
for (int i = 0; i ( str.length; i ++) {
NSString *substr = [str substringWithRange:NSMakeRange(i, 1)];
NSString *a = [dictionary objectForKey:substr];
NSString *b = digits[str.length -i-1];
NSString *sum = [a stringByAppendingString:b];
if ([a isEqualToString:chinese_numerals[9]])
{
if([b isEqualToString:digits[4]] || [b isEqualToString:digits[8]])
{
sum = b;
if ([[sums lastObject] isEqualToString:chinese_numerals[9]])
{
[sums removeLastObject];
}
}else
{
sum = chinese_numerals[9];
}
if ([[sums lastObject] isEqualToString:sum])
{
continue;
}
}
[sums addObject:sum];
}
NSString *sumStr = [sums componentsJoinedByString:@""];
NSString *chinese = [sumStr substringToIndex:sumStr.length-1];
NSLog(@"%@",str);
NSLog(@"%@",chinese);
return chinese;
}
複製程式碼圖片上繪製文字 寫一個UIImage的category
- (UIImage *)imageWithTitle:(NSString *)title fontSize:(CGFloat)fontSize
{
//畫布大小
CGSize size=CGSizeMake(self.size.width,self.size.height);
//建立一個基於點陣圖的上下文
UIGraphicsBeginImageContextWithOptions(size,NO,0.0);//opaque:NO scale:0.0
[self drawAtPoint:CGPointMake(0.0,0.0)];
//文字居中顯示在畫布上
NSMutableParagraphStyle* paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
paragraphStyle.lineBreakMode = NSLineBreakByCharWrapping;
paragraphStyle.alignment=NSTextAlignmentCenter;//文字居中
//計算文字所佔的size,文字居中顯示在畫布上
CGSize sizeText=[title boundingRectWithSize:self.size options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:fontSize]}context:nil].size;
CGFloat width = self.size.width;
CGFloat height = self.size.height;
CGRect rect = CGRectMake((width-sizeText.width)/2, (height-sizeText.height)/2, sizeText.width, sizeText.height);
//繪製文字
[title drawInRect:rect withAttributes:@{ NSFontAttributeName:[UIFont systemFontOfSize:fontSize],NSForegroundColorAttributeName:[ UIColor whiteColor],NSParagraphStyleAttributeName:paragraphStyle}];
//返回繪製的新圖形
UIImage *newImage= UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
複製程式碼UIView設定部分圓角
CGRect rect = view.bounds;
CGSize radio = CGSizeMake(30, 30);//圓角尺寸
UIRectCorner corner = UIRectCornerTopLeft|UIRectCornerTopRight;//這隻圓角位置
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect byRoundingCorners:corner cornerRadii:radio];
CAShapeLayer *masklayer = [[CAShapeLayer alloc]init];//建立shapelayer
masklayer.frame = view.bounds;
masklayer.path = path.CGPath;//設定路徑
view.layer.mask = masklayer;
複製程式碼給UIView設定圖片
UIImage *image = [UIImage imageNamed:@"image"];
self.MYView.layer.contents = (__bridge id _Nullable)(image.CGImage);
self.MYView.layer.contentsRect = CGRectMake(0, 0, 0.5, 0.5);
複製程式碼防止scrollView手勢覆蓋側滑手勢
[scrollView.panGestureRecognizerrequireGestureRecognizerToFail:self.navigationController.interactivePopGestureRecognizer];
複製程式碼去掉導航欄返回的back標題
[[UIBarButtonItem appearance]setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)forBarMetrics:UIBarMetricsDefault];
複製程式碼UITextField每四位加一個空格,實現代理
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
// 四位加一個空格
if ([string isEqualToString:@""])
{
// 刪除字元
if ((textField.text.length - 2) % 5 == 0)
{
textField.text = [textField.text substringToIndex:textField.text.length - 1];
}
return YES;
}
else
{
if (textField.text.length % 5 == 0)
{
textField.text = [NSString stringWithFormat:@"%@ ", textField.text];
}
}
return YES;
}
複製程式碼獲取私有屬性和成員變數 #import(objc/runtime.h)(由於系統原因此處用圓括號代替尖括號) //獲取私有屬性 比如設定UIDatePicker的字型顏色
- (void)setTextColor
{
//獲取所有的屬性，去檢視有沒有對應的屬性
unsigned int count = 0;
objc_property_t *propertys = class_copyPropertyList([UIDatePicker class], &count);
for(int i = 0;i ( count;i ++)
{
//獲得每一個屬性
objc_property_t property = propertys[i];
//獲得屬性對應的nsstring
NSString *propertyName = [NSString stringWithCString:property_getName(property) encoding:NSUTF8StringEncoding];
//輸出列印看對應的屬性
NSLog(@"propertyname = %@",propertyName);
if ([propertyName isEqualToString:@"textColor"])
{
[datePicker setValue:[UIColor whiteColor] forKey:propertyName];
}
}
}
複製程式碼//獲得成員變數 比如修改UIAlertAction的按鈕字型顏色
unsigned int count = 0;
Ivar *ivars = class_copyIvarList([UIAlertAction class], &count);
for(int i =0;i ( count;i ++)
{
Ivar ivar = ivars[i];
NSString *ivarName = [NSString stringWithCString:ivar_getName(ivar) encoding:NSUTF8StringEncoding];
NSLog(@"uialertion.ivarName = %@",ivarName);
if ([ivarName isEqualToString:@"_titleTextColor"])
{
[alertOk setValue:[UIColor blueColor] forKey:@"titleTextColor"];
[alertCancel setValue:[UIColor purpleColor] forKey:@"titleTextColor"];
}
}
複製程式碼獲取手機安裝的應用
Class c =NSClassFromString(@"LSApplicationWorkspace");
id s = [(id)c performSelector:NSSelectorFromString(@"defaultWorkspace")];
NSArray *array = [s performSelector:NSSelectorFromString(@"allInstalledApplications")];
for (id item in array)
{
NSLog(@"%@",[item performSelector:NSSelectorFromString(@"applicationIdentifier")]);
//NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleIdentifier")]);
NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleVersion")]);
NSLog(@"%@",[item performSelector:NSSelectorFromString(@"shortVersionString")]);
}
複製程式碼判斷兩個日期是否在同一周 寫在NSDate的category裡面
- (BOOL)isSameDateWithDate:(NSDate *)date
{
//日期間隔大於七天之間返回NO
if (fabs([self timeIntervalSinceDate:date]) >= 7 * 24 *3600)
{
return NO;
}
NSCalendar *calender = [NSCalendar currentCalendar];
calender.firstWeekday = 2;//設定每週第一天從週一開始
//計算兩個日期分別為這年第幾周
NSUInteger countSelf = [calender ordinalityOfUnit:NSCalendarUnitWeekday inUnit:NSCalendarUnitYear forDate:self];
NSUInteger countDate = [calender ordinalityOfUnit:NSCalendarUnitWeekday inUnit:NSCalendarUnitYear forDate:date];
//相等就在同一周，不相等就不在同一周
return countSelf == countDate;
}
複製程式碼獲取到webview的高度
CGFloat height = [[self.webView stringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];
複製程式碼navigationBar變為純透明
//第一種方法
//導航欄純透明
[self.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
//去掉導航欄底部的黑線
self.navigationBar.shadowImage = [UIImage new];
//第二種方法
[[self.navigationBar subviews] objectAtIndex:0].alpha = 0;
複製程式碼//是否為同一天
+ (BOOL)isSameDay:(NSDate*)date1 date2:(NSDate*)date2
{
NSCalendar* calendar = [NSCalendar currentCalendar];
unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
NSDateComponents* comp1 = [calendar components:unitFlags fromDate:date1];
NSDateComponents* comp2 = [calendar components:unitFlags fromDate:date2];
return [comp1 day] == [comp2 day] && [comp1 month] == [comp2 month] && [comp1 year] == [comp2 year];
}
複製程式碼通過新增一個負值寬度的固定間距的item來解決，也可以改變寬度實現不同的間隔：
UIImage *img = [[UIImage imageNamed:@"icon_cog"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
//寬度為負數的固定間距的系統item
UIBarButtonItem *rightNegativeSpacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
[rightNegativeSpacer setWidth:-15];
UIBarButtonItem *rightBtnItem1 = [[UIBarButtonItem alloc]initWithImage:img style:UIBarButtonItemStylePlain target:self action:@selector(rightButtonItemClicked:)];
UIBarButtonItem *rightBtnItem2 = [[UIBarButtonItem alloc]initWithImage:img style:UIBarButtonItemStylePlain target:self action:@selector(rightButtonItemClicked:)];
self.navigationItem.rightBarButtonItems = @[rightNegativeSpacer,rightBtnItem1,rightBtnItem2];
複製程式碼修改textField的placeholder的字型顏色、大小
[self.textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[self.textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];
複製程式碼AFN移除JSON中的NSNull
AFJSONResponseSerializer *response = [AFJSONResponseSerializer serializer];
response.removesKeysWithNullValues = YES;
複製程式碼NSString過濾特殊字元
// 定義一個特殊字元的集合
NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:
@"@／：；（）¥「」＂、[]{}#%-*+=_\\|~＜＞$€^•'@#$%^&*()_+'\""];
// 過濾字串的特殊字元
NSString *newString = [trimString stringByTrimmingCharactersInSet:set];
複製程式碼去掉分割線多餘15畫素
首先在viewDidLoad方法加入以下程式碼：
if ([self.tableView respondsToSelector:@selector(setSeparatorInset:)]) {
[self.tableView setSeparatorInset:UIEdgeInsetsZero];
}
if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) {
[self.tableView setLayoutMargins:UIEdgeInsetsZero];
}
然後在重寫willDisplayCell方法
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell
forRowAtIndexPath:(NSIndexPath *)indexPath{
if ([cell respondsToSelector:@selector(setSeparatorInset:)]) {
[cell setSeparatorInset:UIEdgeInsetsZero];
}
if ([cell respondsToSelector:@selector(setLayoutMargins:)]) {
[cell setLayoutMargins:UIEdgeInsetsZero];
}
}
複製程式碼計算方法耗時時間間隔
// 獲取時間間隔
#define TICK CFAbsoluteTime start = CFAbsoluteTimeGetCurrent();
#define TOCK NSLog(@"Time: %f", CFAbsoluteTimeGetCurrent() - start)
複製程式碼讓iOS應用直接退出
- (void)exitApplication {
AppDelegate *app = [UIApplication sharedApplication].delegate;
UIWindow *window = app.window;
[UIView animateWithDuration:1.0f animations:^{
window.alpha = 0;
} completion:^(BOOL finished) {
exit(0);
}];
}
複製程式碼Label行間距
-（void）test{
NSMutableAttributedString *attributedString =
[[NSMutableAttributedString alloc] initWithString:self.contentLabel.text];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle setLineSpacing:3];
//調整行間距
[attributedString addAttribute:NSParagraphStyleAttributeName
value:paragraphStyle
range:NSMakeRange(0, [self.contentLabel.text length])];
self.contentLabel.attributedText = attributedString;
}
複製程式碼把tableview裡cell的小對勾的顏色改成別的顏色
_mTableView.tintColor = [UIColor redColor];
複製程式碼螢幕截圖
// 1. 開啟一個與圖片相關的圖形上下文
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size,NO,0.0);
// 2. 獲取當前圖形上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
// 3. 獲取需要擷取的view的layer
[self.view.layer renderInContext:ctx];
// 4. 從當前上下文中獲取圖片
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
// 5. 關閉圖形上下文
UIGraphicsEndImageContext();
// 6. 把圖片儲存到相簿
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
複製程式碼