给图片设置圆角 使用CALayer

现在添加头文件：

#import<QuartzCore/QuartzCore.h>

UIImage *playImage=[UIImageimageNamed:@"pic.png"];

        UIImageView * headerImage = [[UIImageViewalloc] initWithFrame:CGRectMake(10.0, 10.0, 64.0, 64.0)];

        headerImage.image = playImage;

        CALayer * layer = [headerImage layer];

        [layer setMasksToBounds:YES];

        [layer setCornerRadius:20.0];

        [layer setBorderWidth:0.1];

        [layersetBorderColor:[[UIColorblueColor] CGColor]];

此时headerImage便已是具有圆角的UIImageView了