objc Record Screenshot on iPad - 在模拟器上工作但在设备上不工作

Question

我尝试以编程方式录制屏幕截图。在模拟器上，截断的代码非常有效，但在 iPad 上它只有 return 一个空白页：

UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
UIGraphicsBeginImageContextWithOptions(keyWindow.frame.size, NO, 0);

UIView* screenshotView = [[UIScreen mainScreen] snapshotViewAfterScreenUpdates:YES];

[screenshotView drawViewHierarchyInRect:keyWindow.bounds afterScreenUpdates:YES];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

下一行应该return一个视图（包括状态栏）。它在模拟器上工作，但在真实设备上这个视图是空的。

UIView* screenshotView = [[UIScreen mainScreen] snapshotViewAfterScreenUpdates:YES];

什么原因？提前致谢。

Answer 1

如果你想获得 UIImage 对象，不要调用 snapshotViewAfterScreenUpdates API，只需在 keyWindow 上调用 drawViewHierarchyInRect API，但如果你想要已经用图像绘制的视图，则调用 snapshotViewAfterScreenUpdates，那里你不需要调用 drawViewHierarchyInRect API

Answer 2

任何正在寻找正确答案的人：

NSMutableArray* windows = [[[UIApplication sharedApplication] windows] mutableCopy];

NSString *statusBarString = [NSString stringWithFormat:@"_statusBarWindow"];
UIWindow* statusBarWindow =  [[UIApplication sharedApplication] valueForKey:statusBarString];

/*CGRect statusBarFrame = statusBarWindow.frame;
statusBarFrame.origin.x -= 20;
statusBarFrame.origin.y -= 20;
[statusBarWindow setFrame:statusBarFrame];*/
//statusBarWindow.backgroundColor = [UIColor blackColor];
[windows addObject:statusBarWindow];
[statusBarWindow release];



UIGraphicsBeginImageContextWithOptions(imageSize, YES, 0);
CGContextRef context = UIGraphicsGetCurrentContext();
for (UIWindow *window in windows) {
    CGContextSaveGState(context);
    CGContextTranslateCTM(context, window.center.x, window.center.y);
    CGContextConcatCTM(context, window.transform);
    CGContextTranslateCTM(context, -window.bounds.size.width * window.layer.anchorPoint.x, -window.bounds.size.height * window.layer.anchorPoint.y);
    if (orientation == UIInterfaceOrientationLandscapeLeft) {
        CGContextRotateCTM(context, M_PI_2);
        if(![window isKindOfClass:[UIStatusBarWindow class]])
        {
            CGContextTranslateCTM(context, 20, -imageSize.width+20);
        }
        else
        {
            CGContextTranslateCTM(context, 0, -imageSize.width);
        }
    } else if (orientation == UIInterfaceOrientationLandscapeRight) {
        CGContextRotateCTM(context, -M_PI_2);
        if(![window isKindOfClass:[UIStatusBarWindow class]])
        {
            CGContextTranslateCTM(context, -imageSize.height+20, 20);
        }
        else
        {
            CGContextTranslateCTM(context, -imageSize.height, 0);
        }
    } else if (orientation == UIInterfaceOrientationPortraitUpsideDown) {
        CGContextRotateCTM(context, M_PI);
        if(![window isKindOfClass:[UIStatusBarWindow class]])
        {
            CGContextTranslateCTM(context, -imageSize.width+20, -imageSize.height+20);
        }
        else
        {
            CGContextTranslateCTM(context, -imageSize.width, -imageSize.height);
        }
    }
    if ([window respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
        [window drawViewHierarchyInRect:window.bounds afterScreenUpdates:YES];
    } else {
        [window.layer renderInContext:context];
    }
    CGContextRestoreGState(context);
}

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

答案来自 here - 使用上面的解决方案，您也可以捕获状态栏。

PS：检查屏幕截图的正确方向和大小的代码...

objc Record Screenshot on iPad - 在模拟器上工作但在设备上不工作

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objective-c

uiview

ios7