iOS 文字模糊

一开始需求下来是要做成文本被涂抹过的模糊效果,就是既要看的到大概的字,又不能看的很清晰,直接上图

截屏2020-07-28 下午10.20.31.png

然后呢,我就想着用UIVibrancyEffect做,毛玻璃嘛,然后试了一个多小时,找他的各种属性调试,不行,
然后就想着可能需要先把文字转成图片,在加毛玻璃

func image(string:String,font:UIFont,height: CGFloat,width:CGFloat,textAlignment:NSTextAlignment) -> UIImage{
        let str = string as NSString
        let size = CGSize(width: width, height: height)//str.boundingRect(with:
        UIGraphicsBeginImageContext(size)
        let context = UIGraphicsGetCurrentContext()
        UIColor.clear.set()
        let rect = CGRect(x:0, y:0, width: size.width + 200, height : size.height)
        context!.fill(rect)
        let paragraph = NSMutableParagraphStyle()
        paragraph.alignment = .left
       // paragraph.firstLineHeadIndent = 0
       // paragraph.headIndent = 0
       // paragraph.paragraphSpacingBefore = 0
       // paragraph.paragraphSpacing = 0
       // paragraph.lineSpacing = 0
        let attributes = [NSAttributedString.Key.foregroundColor : UIColor.black,
                          NSAttributedString.Key.font : font,
                          NSAttributedString.Key.paragraphStyle:paragraph
                         ]
        str.draw(in: rect, withAttributes: attributes)
        let image = UIGraphicsGetImageFromCurrentImageContext()

        UIGraphicsEndImageContext()

        return image!

    }

也不行,去百度和谷歌都找不到相应的东西,然后为了发版本,只能先盖一张固定的模糊过的文字图片上去做做样子(感谢UI妹纸的配合),先发了版本再说,于是过了几天,我突然想到一个东西:CIFilter,他也可以做模糊的呀,于是我找了下资料

// CIGaussianBlur   高斯模糊
// CIBoxBlur        均值模糊
// CIDiscBlur       环形卷积模糊
// CIMotionBlur     运动模糊
CIFilter *filter = [CIFilter filterWithName:@"CIMotionBlur"];

运动模糊应该就是我要的效果了
于是直接试了一下

let inputImg = self.image(string: label.text!, font: UIFont.systemFont(ofSize: 22),height:label.frame.size.height,  width: label.frame.size.width, textAlignment: .left)
let input = CIImage(cgImage: inputImg.cgImage!)
let filter = CIFilter(name: "CIMotionBlur")
filter?.setValue(input, forKey: kCIInputImageKey)
filter?.setValue(NSNumber(value: 8), forKey: kCIInputRadiusKey)
let context = CIContext(options: nil)
let outputImg = filter?.outputImage
let imgRef = context.createCGImage(outputImg!, from: outputImg!.extent)
imageV.image = UIImage.init(cgImage: imgRef!)

也就是上面那个效果,不过此处有个问题,模糊图片前面会有一段空白,这个是在文本转图片的时候存在的问题,我也试了修改NSMutableParagraphStyle的属性值,也就是我所注释掉的那部分代码,即使加了那些也没有办法把文字开头的空白去掉,只能带改天研究如何做到文本和文字一样等高等宽了.
如果有什么遗漏的或者知道怎么解决这个问题的小伙伴,还请不吝赐教.