objective-c - 创建 UIImage 抠图

Question

我有一个包含 2 个 UIImageViews 的 UIView - 一个框架和框架后面的图片。框架不是矩形 - 它是不规则形状。用户可以操纵框架后面的图片(缩放、旋转和平移)，完成后，我想在框架内捕获图片的剪切 - 而不是图片和框架在一起。我有办法做到这一点吗？

我已经设法将图片和框架拼合成一个图像，如下所示，但我只想要图片，如果成功提取，它将有一个框架形状的边框。

- (IBAction)renderPhoto:(id)sender {
    //Combine the layers into a single image
    UIView *canvas = [[[sender superview] subviews] objectAtIndex:0];
    UIGraphicsBeginImageContext(canvas.bounds.size);
    [canvas.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *combinedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
}

Answer 1

使用我的这个方法..

- (UIImage*)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect
{

    UIGraphicsBeginImageContext(photo.frame.size);/// use your screen or photo frame
    [photo.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();



    CGImageRef imageRef = CGImageCreateWithImageInRect([screenshot CGImage], rect);
    UIImage *cropped = [UIImage imageWithCGImage:imageRef];

    /*    no origin .....
    UIGraphicsBeginImageContext(tempview.frame.size);
    [[self.photo layer] renderInContext:UIGraphicsGetCurrentContext()];   
    cropped= UIGraphicsGetImageFromCurrentImageContext();    
    UIGraphicsEndImageContext(); 
    */
        return cropped;
}

希望，这对你有帮助......:)