截取小图

- (UIImage*)getImageFromView:(UIView*)view atFrame:(CGRect)frame
{
    UIGraphicsBeginImageContext(view.frame.size);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGContextSaveGState(ctx);
//    UIRectClip(frame);
    [view.layerrenderInContext:ctx];
    UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
    UIImage * smallImage = [UIImageimageWithCGImage:CGImageCreateWithImageInRect([imageCGImage], frame)];

    UIGraphicsEndImageContext();
    return smallImage;
   
}

上边代码可以实现在视图中截取指定frame的图片。

保存到相册中：UIImageWriteToSavedPhotosAlbum(smallImage,self,nil,nil);