动画图像屏幕截图

Question

我有一个图像视图，它每隔几秒钟就会随着卷曲动画而改变。我想拍一段视频，所以我所做的就是，我每秒都会截取屏幕截图，并从中创建视频。但是当图像是动画的时候，我无法截取屏幕截图，那时它会返回图像稳定或没有动画的截图。

我使用下面的代码来截取图像的屏幕截图

{
    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] presentationLayer] renderInContext:context];

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

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

    UIGraphicsEndImageContext();

    return image;
}

有人知道这件事吗？

提前谢谢。

-Austin

Answer 1

我认为你应该使用：

[[[[window contentView] layer] presentationLayer] renderInContext:context];

为了捕获动画的当前状态，而不是源或目标状态

Answer 2

根据您的代码，您似乎是在截取屏幕。所以你可以试试这个：

[[UIScreen mainScreen] snapshotViewAfterScreenUpdates:NO]

否则：

[yourAnimatedView.layer.presentationLayer snapshotViewAfterScreenUpdates:NO]