拷貝被人的drawRect繪圖分類用途，用法很全。留著、供用時參考
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
/*NO.1畫一條線
CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//線條顏色
CGContextMoveToPoint(context, 20, 20);
CGContextAddLineToPoint(context, 200,20);
CGContextStrokePath(context);
*/
/*NO.2寫文字
CGContextSetLineWidth(context, 1.0);
CGContextSetRGBFillColor (context, 0.5, 0.5, 0.5, 0.5);
UIFont *font = [UIFont boldSystemFontOfSize:18.0];
[@"公司：北京中軟科技股份有限公司\n部門：ERP事業部\n姓名：McLiang" drawInRect:CGRectMake(20, 40, 280, 300) withFont:font];
*/
/*NO.3畫一個正方形圖形 沒有邊框
CGContextSetRGBFillColor(context, 0, 0.25, 0, 0.5);
CGContextFillRect(context, CGRectMake(2, 2, 270, 270));
CGContextStrokePath(context);
*/
/*NO.4畫正方形邊框
CGContextSetRGBStrokeColor(context, 0.5, 0.5, 0.5, 0.5);//線條顏色
CGContextSetLineWidth(context, 2.0);
CGContextAddRect(context, CGRectMake(2, 2, 270, 270));
CGContextStrokePath(context);
*/
/*NO.5畫方形背景顏色
CGContextTranslateCTM(context, 0.0f, self.bounds.size.height);
CGContextScaleCTM(context, 1.0f, -1.0f);
UIGraphicsPushContext(context);
CGContextSetLineWidth(context,320);
CGContextSetRGBStrokeColor(context, 250.0/255, 250.0/255, 210.0/255, 1.0);
CGContextStrokeRect(context, CGRectMake(0, 0, 320, 460));
UIGraphicsPopContext();
*/
/*NO.6橢圓
CGRect aRect= CGRectMake(80, 80, 160, 100);
CGContextSetRGBStrokeColor(context, 0.6, 0.9, 0, 1.0);
CGContextSetLineWidth(context, 3.0);
CGContextAddEllipseInRect(context, aRect); //橢圓
CGContextDrawPath(context, kCGPathStroke);
*/
/*NO.7
CGContextBeginPath(context);
CGContextSetRGBStrokeColor(context, 0, 0, 1, 1);
CGContextMoveToPoint(context, 100, 100);
CGContextAddArcToPoint(context, 50, 100, 50, 150, 50);
CGContextStrokePath(context);
*/
/*NO.8漸變
CGContextClip(context);
CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB();
CGFloat colors[] =
{
204.0 / 255.0, 224.0 / 255.0, 244.0 / 255.0, 1.00,
29.0 / 255.0, 156.0 / 255.0, 215.0 / 255.0, 1.00,
0.0 / 255.0, 50.0 / 255.0, 126.0 / 255.0, 1.00,
};
CGGradientRef gradient = CGGradientCreateWithColorComponents
(rgb, colors, NULL, sizeof(colors)/(sizeof(colors[0])*4));
CGColorSpaceRelease(rgb);
CGContextDrawLinearGradient(context, gradient,CGPointMake
(0.0,0.0) ,CGPointMake(0.0,self.frame.size.height),
kCGGradientDrawsBeforeStartLocation);
*/
/* NO.9四條線畫一個正方形
//畫線
UIColor *aColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0];
CGContextSetRGBStrokeColor(context, 1.0, 0, 0, 1.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
CGContextSetLineWidth(context, 4.0);
CGPoint aPoints[5];
aPoints[0] =CGPointMake(60, 60);
aPoints[1] =CGPointMake(260, 60);
aPoints[2] =CGPointMake(260, 300);
aPoints[3] =CGPointMake(60, 300);
aPoints[4] =CGPointMake(60, 60);
CGContextAddLines(context, aPoints, 5);
CGContextDrawPath(context, kCGPathStroke); //開始畫線
*/
/* NO.10
UIColor *aColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0];
CGContextSetRGBStrokeColor(context, 1.0, 0, 0, 1.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
//橢圓
CGRect aRect= CGRectMake(80, 80, 160, 100);
CGContextSetRGBStrokeColor(context, 0.6, 0.9, 0, 1.0);
CGContextSetLineWidth(context, 3.0);
CGContextSetFillColorWithColor(context, aColor.CGColor);
CGContextAddRect(context, rect); //矩形
CGContextAddEllipseInRect(context, aRect); //橢圓
CGContextDrawPath(context, kCGPathStroke);
*/
/* NO.11
畫一個實心的圓
CGContextFillEllipseInRect(context, CGRectMake(95, 95, 100.0, 100));
*/
/*NO.12
畫一個菱形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 150);
CGContextAddLineToPoint(context, 100, 200);
CGContextAddLineToPoint(context, 50, 150);
CGContextAddLineToPoint(context, 100, 100);
CGContextStrokePath(context);
*/
/*NO.13 畫矩形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddRect(context, rectangle);
CGContextStrokePath(context);
*/
/*橢圓
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddEllipseInRect(context, rectangle);
CGContextStrokePath(context);
*/
/*用紅色填充了一段路徑:
CGContextMoveToPoint(context, 100, 100);
CGContextAddLineToPoint(context, 150, 150);
CGContextAddLineToPoint(context, 100, 200);
CGContextAddLineToPoint(context, 50, 150);
CGContextAddLineToPoint(context, 100, 100);
CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
CGContextFillPath(context);
*/
/*填充一個藍色邊的紅色矩形
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGRect rectangle = CGRectMake(60,170,200,80);
CGContextAddRect(context, rectangle);
CGContextStrokePath(context);
CGContextSetFillColorWithColor(context, [UIColor redColor].CGColor);
CGContextFillRect(context, rectangle);
*/
/*畫弧
//弧線的是通過指定兩個切點，還有角度，呼叫CGContextAddArcToPoint()繪製
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 100, 100);
CGContextAddArcToPoint(context, 100,200, 300,200, 100);
CGContextStrokePath(context);
*/
/*
繪製貝茲曲線
//貝茲曲線是通過移動一個起始點，然後通過兩個控制點,還有一箇中止點，呼叫CGContextAddCurveToPoint() 函式繪製
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 10, 10);
CGContextAddCurveToPoint(context, 0, 50, 300, 250, 300, 400);
CGContextStrokePath(context);
*/
/*繪製二次貝茲曲線
CGContextSetLineWidth(context, 2.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, 10, 200);
CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
CGContextStrokePath(context);
*/
/*繪製虛線
CGContextSetLineWidth(context, 5.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGFloat dashArray[] = {2,6,4,2};
CGContextSetLineDash(context, 3, dashArray, 4);//跳過3個再畫虛線，所以剛開始有6-（3-2）=5個虛點
CGContextMoveToPoint(context, 10, 200);
CGContextAddQuadCurveToPoint(context, 150, 10, 300, 200);
CGContextStrokePath(context);
*/
/*繪製圖片
NSString* imagePath = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage* myImageObj = [[UIImage alloc] initWithContentsOfFile:imagePath];
//[myImageObj drawAtPoint:CGPointMake(0, 0)];
[myImageObj drawInRect:CGRectMake(0, 0, 320, 480)];
NSString *s = @"我的小狗";
[s drawAtPoint:CGPointMake(100, 0) withFont:[UIFont systemFontOfSize:34.0]];
*/
/*
NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);
*/
/*NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGContextRotateCTM(context, M_PI);
CGContextTranslateCTM(context, -img.size.width, -img.size.height);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);*/
/*
NSString *path = [[NSBundle mainBundle] pathForResource:@"dog" ofType:@"png"];
UIImage *img = [UIImage imageWithContentsOfFile:path];
CGImageRef image = img.CGImage;
CGContextSaveGState(context);
CGAffineTransform myAffine = CGAffineTransformMakeRotation(M_PI);
myAffine = CGAffineTransformTranslate(myAffine, -img.size.width, -img.size.height);
CGContextConcatCTM(context, myAffine);
CGContextRotateCTM(context, M_PI);
CGContextTranslateCTM(context, -img.size.width, -img.size.height);
CGRect touchRect = CGRectMake(0, 0, img.size.width, img.size.height);
CGContextDrawImage(context, touchRect, image);
CGContextRestoreGState(context);
*/
}