UIBezierPath：视图屏幕截图的检索不正确

Question

我正在按照下面的方式截取屏幕截图。

- (UIImage*)screenshot 
{
    UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
    CGRect rect = [keyWindow bounds];
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [keyWindow.layer renderInContext:context];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return img;
}

在UIView上我使用UIBezierPath绘制路径。

我得到的屏幕截图不正确

为什么上半部分被切成空白的任何想法？在UIView上，所有绘图都正确显示。

---

更新：当我使用UIBezierPath绘制一条长路径时，当我释放我的画笔并获取截图时，它会正确获取截图。

Answer 1

我看到了你发布的另一个帖子。 根据{{​​3}}，您需要先调整几何坐标。 因此，在渲染窗口层之前，请先执行以下操作。

// -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);

Answer 2

- (UIImage*)screenshot :(UIView*)vw
{

    CGRect rect = [vw bounds];
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [vw.layer renderInContext:context];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return img;
}

使用此

Answer 3

-(IBAction)takeScreenShot:(id)sender
{

    UIGraphicsBeginImageContext(self.view.bounds.size); 

    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()]; 

    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
}