UIScreen上的snapshotViewAfterScreenUpdates为设备提供了空白快照

I'm trying to get an image of the entire screen as the user sees it. The following code should work however it will only work in the simulator. What do I have to do to get this to work on a device running iOS 8.1?

我试着在用户看到的时候得到整个屏幕的图像。下面的代码应该可以工作，但是它只能在模拟器中工作。在运行iOS 8.1的设备上，我需要做什么才能让它工作呢?

UIView *snapshot = [[UIScreen mainScreen] snapshotViewAfterScreenUpdates:YES];
CGSize outputSize = CGSizeMake([UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
UIGraphicsBeginImageContextWithOptions(outputSize, NO, 0);
[snapshot drawViewHierarchyInRect:CGRectMake(0.0, 0.0, outputSize.width, outputSize.height) afterScreenUpdates:YES];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

Happy to try alternative strategies but the key is I want it as the user sees it - keyboards and all.

很乐意尝试不同的策略，但关键是我想让用户看到它——键盘和所有的东西。

Cheers

干杯

1 个解决方案

#1

UIGraphicsBeginImageContextWithOptions(CGSizeMake(CGRectGetWidth(self.view.frame), CGRectGetHeight(self.view.frame)), NO, 1.0f);
        [self.view drawViewHierarchyInRect:CGRectMake(0, 0, CGRectGetWidth(self.view.frame), CGRectGetHeight(self.view.frame)) afterScreenUpdates:NO];
        UIImage *snapshotImage = UIGraphicsGetImageFromCurrentImageContext();