ios圖片截取

- (UIImage *)clipImage:(UIImage *)image imageoritation:(UIImageOrientation)oritation withRect:(CGRect)rect
{
    CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], rect);
    UIImage *clipImage = [UIImage imageWithCGImage:imageRef scale:image.scale orientation:oritation];//UIImageOrientationLeft
    CGImageRelease(imageRef);
    return clipImage;
}