Blur View works in Simulator but not on device

Question

I added a blur view in my app. If I run the app in the Simulator (iPhone 6, iOS 8.4) all works fine and the blur view is displayed. If I run the app on an device (iPad 3rd Gen., iOS 8.4) the blur view is displayed but doesn't displays a blurred background instead of this it displays a grey background. Don't know why. Do you know why and how to solve it?

Are you making sure to add your subviews of the blur view to the blur views contentView property? if you don't add subviews here I believe the behaviour is undefined. I would need to see screenshots to have a better idea what is happening. — Martin O'Shea, Oct 25 '15 at 22:22
No it's also not working in the iPad Simulator. Don't know what to do. Example (grey part is the blur view): https://www.dropbox.com/s/e77uinulbqjmu81/Bildschirmfoto%202015-10-25%20um%2023.31.37.png?dl=0 — user5473123, Oct 25 '15 at 22:31

score 0 · Answer 1 · answered Oct 27 '15 at 07:47

What code you are using?

func BlurEffect(){
     let extraLightBlur = UIBlurEffect(style: .Dark)
            let extraLightBlurView = UIVisualEffectView(effect: extraLightBlur)
            self.addSubview(extraLightBlurView)

            //let blurAreaAmount = CGRectMake(0, 0, frame.size.width, frame.size.height)
            extraLightBlurView.frame = CGRectMake(0, 0, frame.size.width, frame.size.height)
            let extraLightVibrancyView = vibrancyEffectView(forBlurEffectView: extraLightBlurView)
            extraLightBlurView.contentView.addSubview(extraLightVibrancyView)
        }

        private func vibrancyEffectView(forBlurEffectView blurEffectView:UIVisualEffectView) -> UIVisualEffectView {
            let vibrancy = UIVibrancyEffect(forBlurEffect: blurEffectView.effect as! UIBlurEffect)
            let vibrancyView = UIVisualEffectView(effect: vibrancy)
            vibrancyView.frame = blurEffectView.frame
            //vibrancyView.autoresizingMask = .FlexibleWidth | .FlexibleHeight
            return vibrancyView
        }

Yes I use this part of code but the style is `Light` not `Dark`. — user5473123, Oct 27 '15 at 12:55
I checked this code with iPhone 6+ (iOS 8.4). Its working well. — Pravin S., Oct 27 '15 at 14:45

score 0 · Answer 2 · answered Sep 11 '16 at 17:45

I ran into this problem too and wound up rolling my own blur effect using Core Image to create a UIView category. It works on a very old iPad mini and an iPod touch.

The header

//
//  UIView+CIFilters.h
//

#import <UIKit/UIKit.h>
@interface UIView (CIFilters)
- (UIImageView *)blurredBackgroundViewWithRadius:(CGFloat)radius;
@end

The category

#import "UIView+CIFilters.h"

@implementation UIView (CIFilters)

- (UIImageView *)blurredBackgroundViewWithRadius:(CGFloat)radius {

    UIView *snapshot = self;
    // Get a CIImage from the view's contents
    UIGraphicsBeginImageContextWithOptions(snapshot.bounds.size, snapshot.opaque, 0);
    [snapshot drawViewHierarchyInRect:snapshot.bounds afterScreenUpdates:YES];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    CIImage *snapshotImage = [CIImage imageWithCGImage:image.CGImage];

    //  Create a filter.
    //  This has to be applied first so that the edges of the CIGaussianBlur reach to the edge of the screen
    //  See the Core Image Filter Reference
    CIFilter *clampFilter = [CIFilter filterWithName:@"CIAffineClamp"
                                 withInputParameters:@{
                                                       kCIInputImageKey: snapshotImage
                                                       }];

    CIImage *clampImage = [clampFilter valueForKey:kCIOutputImageKey];

    CIFilter *blurFilter = [CIFilter filterWithName:@"CIGaussianBlur"
                                withInputParameters:@{
                                                      kCIInputImageKey: clampImage,
                                                      kCIInputRadiusKey:@(radius)
                                                      }
                            ];
    CIImage *blurredCIImage = [blurFilter valueForKey: kCIOutputImageKey];

    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef cgImage = [context createCGImage:blurredCIImage fromRect:[snapshotImage extent]];

    UIImage *blurredImage = [UIImage imageWithCGImage:cgImage];
    UIImageView *blurredSnaphotview = [[UIImageView alloc] initWithImage:blurredImage];

    return blurredSnaphotview;
}

@end

For example

UIImageView *blurredSnapshot = [self.view blurredBackgroundViewWithRadius:10.0];

will make a blurred snapshot of the entire view hierarchy of self.view where self is the current view controller. The larger the radius the blurrier the image. Substitute this view for a UIVisualEffectView.

Be sure to add CoreImage to your project frameworks.

Blur View works in Simulator but not on device

2 Answers2