将 UIView 捕获为 UIImage

Question

我一直在使用这种方法将 UIView 转换为 UIImage。即视图的屏幕快照 -

@interface UIView(Extended) 

- (UIImage *) imageByRenderingView;

@end


@implementation UIView(Extended)


- (UIImage *)imageByRenderingView
{   
    UIGraphicsBeginImageContext(self.bounds.size);
    [self.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return resultingImage;
}

@end

要使用它，我这样做 -

UIImage *currImage = [self.view imageByRenderingView];

这给出了整个 UIView 的图像表示。现在我想要两张图像，一张是 UIView 的上半部分，另一张是下半部分。我该怎么做？

Answer 1

您可以使用以下代码将 UIImage 一分为二：

CGImageRef topOfImageCG =
         CGImageCreateWithImageInRect(currImage.CGImage,
                                      CGRectMake(0,
                                                 0,
                                                 currImage.size.width,
                                                 currImage.size.height / 2.0));

UIImage *topOfImage = [UIImage imageWithCGImage:topOfImageCG];

CGImageRelease(topOfImageCG);