1

我想实现passcode view的效果（壁纸图片模糊变暗）

这给了我一个黑屏

func blurWithCoreImage(){

    var inputImage = CIImage(image: UIImage(named: "wallpaper"));

    // Apply gaussian blur filter with radius of 30
    var gaussianBlurFilter = CIFilter(name: "CIGaussianBlur");
    gaussianBlurFilter.setValue(inputImage, forKey: "inputImage")
    gaussianBlurFilter.setValue(30, forKey: "inputRadius")

    var context  =  CIContext(options:nil)
    var cgImage = context.createCGImage(gaussianBlurFilter.outputImage, fromRect: inputImage.extent())

    // Set up output context.
    UIGraphicsBeginImageContext(self.view.frame.size);
    var outputContext = UIGraphicsGetCurrentContext();

    // Invert image coordinates
    CGContextScaleCTM(outputContext, 1.0, -1.0);
    CGContextTranslateCTM(outputContext, 0, -self.view.frame.size.height);

    // Draw base image.
    CGContextDrawImage(outputContext, self.view.frame, cgImage);

    // Apply white tint
    CGContextSaveGState(outputContext);
    //  CGContextSetFillColorWithColor(outputContext, UIColor.blackColor().CGColor!);

    CGContextFillRect(outputContext, self.view.frame);
    CGContextRestoreGState(outputContext);

    // Output image is ready.
    var outputImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    backgroundImg.image =  outputImage;
}

此功能使图像模糊，但同时缩小图像，在密码视图中效果太远

func blurWithCoreImage2(){
    var ciimage = CIImage(image: UIImage(named: "passcode"))

    var filter = CIFilter(name:"CIGaussianBlur")

    filter.setDefaults()

    filter.setValue(ciimage, forKey: kCIInputImageKey)

    filter.setValue(1, forKey: kCIInputRadiusKey)

    var outputImage = filter.outputImage;

    var finalImage = UIImage(CIImage: outputImage);
    backgroundImg.image =  finalImage;
    UIGraphicsEndImageContext();

}
4

3 回答 3

13

由于您只需要支持 iOS 8 及更高版本，您就可以使用 new UIVisualEffectView，这是新的内置添加模糊的方式。

它非常易于使用，如下所示：

let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
let blurView = UIVisualEffectView(effect: blurEffect)
blurView.frame = myFrame
self.view.addSubview(blurView)

您可以看到您可以指定 a UIBlurEffectStyle，这也将允许您使其更暗。

于 2014-10-23T12:10:38.837 回答
2

试试这个来模糊和裁剪图像

func applyBlurEffect(image: UIImage){
var imageToBlur = CIImage(image: image)
var blurfilter = CIFilter(name: "CIGaussianBlur")
blurfilter.setValue(5, forKey: kCIInputRadiusKey)
blurfilter.setValue(imageToBlur, forKey: "inputImage")
var resultImage = blurfilter.valueForKey("outputImage") as! CIImage
var blurredImage = UIImage(CIImage: resultImage)
var cropped:CIImage=resultImage.imageByCroppingToRect(CGRectMake(0, 0,imageToBlur.extent().size.width, imageToBlur.extent().size.height))
blurredImage = UIImage(CIImage: cropped)
self.backgroundImage.image = blurredImage
}
于 2015-09-04T08:06:46.067 回答
0

我尝试更新答案，但毫无意义地被拒绝了。这是最新的语法：

斯威夫特 3.1

let blurEffect = UIBlurEffect(style: .dark)
let blurView = UIVisualEffectView(effect: blurEffect)
self.view.addSubview(blurView)
于 2017-05-17T07:01:51.443 回答