使用UIButton截取UIView的屏幕截图

Question

我正在尝试制作一个带有按钮的应用程序，该按钮将对设备屏幕上绘制的对象进行截屏并保存在设备的照片库中... 你有什么想法吗？如何实现这个功能？

- Cristiano

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你需要截取整个屏幕的截图吗？ - Gypsa

Answer 1

    UIGraphicsBeginImageContext(self.view.bounds.size);
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *screenShotimage = UIGraphicsGetImageFromCurrentImageContext();
    UIImageWriteToSavedPhotosAlbum(screenShotimage, nil, nil, nil);
    UIGraphicsEndImageContext();

这段代码将会拍下你屏幕的截图并保存在照片库中。

- Gypsa

Answer 2

苹果公司在这里描述了一种方法：http://developer.apple.com/library/ios/#qa/qa1703/_index.html

- (UIImage*)screenshot 
{
// Create a graphics context with the target size
// On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration
// On iOS prior to 4, fall back to use UIGraphicsBeginImageContext
CGSize imageSize = [[UIScreen mainScreen] bounds].size;
if (NULL != UIGraphicsBeginImageContextWithOptions)
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
else
    UIGraphicsBeginImageContext(imageSize);

CGContextRef context = UIGraphicsGetCurrentContext();

// Iterate over every window from back to front
for (UIWindow *window in [[UIApplication sharedApplication] windows]) 
{
    if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
    {
        // -renderInContext: renders in the coordinate space of the layer,
        // so we must first apply the layer's geometry to the graphics context
        CGContextSaveGState(context);
        // Center the context around the window's anchor point
        CGContextTranslateCTM(context, [window center].x, [window center].y);
        // Apply the window's transform about the anchor point
        CGContextConcatCTM(context, [window transform]);
        // Offset by the portion of the bounds left of and above the anchor point
        CGContextTranslateCTM(context,
                              -[window bounds].size.width * [[window layer] anchorPoint].x,
                              -[window bounds].size.height * [[window layer] anchorPoint].y);

        // Render the layer hierarchy to the current context
        [[window layer] renderInContext:context];

        // Restore the context
        CGContextRestoreGState(context);
    }
}

// Retrieve the screenshot image
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;
}

记得引入 #import <QuartzCore/QuartzCore.h> 。

- bogen

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如果您的UIView具有遮罩图层，这将无法正常工作。 - Quaso

@Haaakon 抱歉，该页面无法找到。链接不可用。 - SwapnilPopat