将UIVisualEffectView添加到UITableView的背景视图仅适用于模拟器而非设备

Question

I have a UITableView with a UIImageView as the backgroundView . This works like a charm. However, now I'm trying to blur this image (using UIVisualEffectView ) so that the background of the tableView looks blurred. However, my code somehow ignores the image and simply blurs the white background of the table view. Here is the code:

UIImageView *tempImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"sidebarImage"]];
UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *blurEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
[blurEffectView setFrame:tempImageView.bounds];
[tempImageView addSubview:blurEffectView];
self.tableView.backgroundView = tempImageView;

EDIT: After some more testing, I found that this works on the simulator, but not on the actual device. I have attached screenshots below a well. What's even more surprising is that when I comment out [tempImageView addSubview:blurEffectView] ; the image shows up. That means the image is being copied to the phone.

Answer 1

This has got to be one of the silliest problems I encountered. Apparently, I had "Reduce Transparency" switched on in my iphone settings. Hence the problem. Hope this helps some other poor soul trying to conserve battery.

Answer 2

You can detect when "Reduce Transparency" is enabled in iOS 8+ using:

if (UIAccessibilityIsReduceTransparencyEnabled()) {
   ...
}

This blog post goes more in depth on detecting whether UIVisualEffectView is available on a device.

Answer 3

try this

 UIImageView *tempImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"sidebarImage"]];
    UIBlurEffect *blurEffect;
    blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];

    UIVisualEffectView * blurEffectView;
    blurEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];


    blurEffectView.frame = tempImageView.bounds;
    [tempImageView addSubview:blurEffectView];
    self.tableView.backgroundView = tempImageView;

look at this