[英]iOS make screenshot of entire screen issue
我有图像视图的自我看法:
UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.bounds];
[self setBluredImageView:imageView];
[self addSubview:imageView];
- (UIImage *)takeSnapshotOfView:(UIView *)view
{
CGFloat reductionFactor = 1;
UIGraphicsBeginImageContext(CGSizeMake(view.frame.size.width/reductionFactor, view.frame.size.height/reductionFactor));
[view drawViewHierarchyInRect:CGRectMake(0, 0, view.frame.size.width/reductionFactor, view.frame.size.height/reductionFactor) afterScreenUpdates:YES];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
在方法中,当我想在其他视图上显示自己的视图时,我这样做:
- (void)showMe; {
AppDelegate* app = [AppDelegate shared];
[app.window addSubview:self];
UIImage *image = [self blurWithImageEffects:[self takeSnapshotOfView:app.window]];
[[self bluredImageView] setImage:image];
[UIView animateWithDuration:0.4 animations:^{
[self setAlpha:1.0];
}];
}
如您所见,我想模糊基于主窗口视图的“图形上下文”。 第一次显示自我视图时,它可以完美工作,但是随后,诸如模糊图像之类的东西会彼此相乘。
所以这是我刚开始显示视图时的图像:
当我几次提出视图时,模糊的图像看起来像这样:
因此,您可以看到每次模糊的屏幕截图都是不同的,但是我使用相同的方法来获取屏幕截图,并且不更新视图控制器或其他ui部件的内容。
一些方法和图像类别在这里找到。
您已经创建了一个模糊循环。 当您第二次获取视图的屏幕截图时,blurredImageView也在屏幕截图中。 这就是为什么您看到效果成倍增长的原因。 尝试删除它,只捕获没有效果的上下文,然后将其重新添加
- (UIImage *)takeSnapshotOfView:(UIView *)view
{
//Remove the blured image before taking another screenshot.
[self bluredImageView] removeFromSuperview];
CGFloat reductionFactor = 1;
UIGraphicsBeginImageContext(CGSizeMake(view.frame.size.width/reductionFactor, view.frame.size.height/reductionFactor));
[view drawViewHierarchyInRect:CGRectMake(0, 0, view.frame.size.width/reductionFactor, view.frame.size.height/reductionFactor) afterScreenUpdates:YES];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//Add it back now that the effect is done
[self addSubview:[self bluredImageView];
return image;
}
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