Draw roundCorner image in iPhone with sdk_drawroundimage-优快云博客

本文介绍了一种在 iOS 应用中实现图片圆角显示的方法。通过自定义 Core Graphics 函数来绘制带圆角的矩形路径，并利用此路径裁剪图片。此外，还提供了一个更简便的方式：直接设置 UIImageView 的 layer 属性来实现图片圆角效果。

static void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth,float ovalHeight) { float fw, fh; if (ovalWidth == 0 || ovalHeight == 0) { CGContextAddRect(context, rect); return; } CGContextSaveGState(context); CGContextTranslateCTM (context, CGRectGetMinX(rect), CGRectGetMinY(rect)); CGContextScaleCTM (context, ovalWidth, ovalHeight); fw = CGRectGetWidth (rect) / ovalWidth; fh = CGRectGetHeight (rect) / ovalHeight; CGContextMoveToPoint(context, fw, fh/2); CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1); CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); CGContextClosePath(context); CGContextRestoreGState(context); } - (UIImage *) roundCorners: (UIImage*) img { int w = img.size.width; int h = img.size.height; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst); CGContextBeginPath(context); CGRect rect = CGRectMake(0, 0, img.size.width, img.size.height); addRoundedRectToPath(context, rect, 100, 100); CGContextClosePath(context); CGContextClip(context); CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage); CGImageRef imageMasked = CGBitmapContextCreateImage(context); CGContextRelease(context); CGColorSpaceRelease(colorSpace); [img release]; return [UIImage imageWithCGImage:imageMasked]; } // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { image = [UIImage imageNamed:@"Free.png"]; imaged = [self roundCorners:image]; CGRect myImageRect = CGRectMake(30.0f, 30.0f, 160.0f, 230.0f); UIImageView *myImage = [[UIImageView alloc] initWithFrame:myImageRect]; [myImage setImage:imaged]; //myImage.opaque = YES; // explicitly opaque for performance [self.view addSubview:myImage]; [myImage release]; [super viewDidLoad]; }

参照别的的做的一个，现在好像有个什么简单的，直接设置属性就可以了

//还没测试，测试一下再修改

图片圆角 image round corner: m_mainImgView.layer.cornerRadius = 6; m_mainImgView.layer.masksToBounds = YES; 自动适应,保持图片宽高比 aspect fit: m_mainImgView.contentMode = UIViewContentModeScaleAspectFit;