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- (UIView *)containerBackgroundView {
if (!_containerBackgroundView) {
UIToolbar *toolBar = [[UIToolbar alloc] initWithFrame:CGRectZero];
toolBar.barStyle = UIBarStyleBlack;
toolBar.clipsToBounds = YES;
_containerBackgroundView = toolBar;
}
return _containerBackgroundView;
}
You can also use UIBlurEffect:
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UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *blurView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
blurView.frame = myView.bounds;
[myView addSubview:blurView];
UIBlurEffectStyle
UIBlurEffectStyleExtraLight,//Extra brightness (highlight style)
UIBlurEffectStyleLight,//Light style
UIBlurEffectStyleDark//Dark style
UIBlurEffect cannot adjust the blur radius.
If you want to adjust the blur radius,
you can apply a Gaussian blur to the image:
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-(UIImage *)convertToBlurImage:(UIImage *)image{
CIFilter *gaussianBlurFilter = [CIFilter filterWithName:@"CIGaussianBlur"];
[gaussianBlurFilter setDefaults];
CIImage *inputImage = [CIImage imageWithCGImage:[image CGImage]];
[gaussianBlurFilter setValue:inputImage forKey:kCIInputImageKey];
[gaussianBlurFilter setValue:@5 forKey:kCIInputRadiusKey];
CIImage *outputImage = [gaussianBlurFilter outputImage];
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef cgimg = [context createCGImage:outputImage fromRect:[inputImage extent]]; // note, use input image extent if you want it the same size, the output image extent is larger
UIImage *convertedImage = [UIImage imageWithCGImage:cgimg];
return convertedImage;
}
The core line is [gaussianBlurFilter setValue:@5 forKey:kCIInputRadiusKey];
I tested 100 and it worked fine too — I never found the maximum value.
Above are several pieces of Gaussian blur related code.
End of article