iOS 切割图片

 - (UIImage *)CutImageWithImage:(UIImage *)image withRect:(CGRect)rect

 {

     //使用CGImageCreateWithImageInRect方法切割图片，第一个参数为CGImage类型，第二个参数为要切割的CGRect

     CGImageRef cutImage = CGImageCreateWithImageInRect(image.CGImage, rect);

     //将切割出得图片转换为UIImage

     UIImage *resultImage = [UIImage imageWithCGImage:cutImage];

     return resultImage;

 }