如何使用 Swift 降低 UITextView 中文本的质量 [英] How to reduce the quality of the text inside UITextView with Swift

问题描述

我试图在发送消息之前降低消息的质量，例如，如果连接很差，我想模糊 UITextView 中的文本，如果连接改善或互联网出现返回，然后移除模糊并在 UITextView 中显示普通文本.我试过使用 CATextLayer 不起作用.有什么办法可以做到这一点吗?

I'm trying to reduce the quality of a message before its being sent, for example if the connect is poor I want to blur out the text in the UITextView and if connection improves or internet comes back, then remove the blur and show the normal text in the UITextView. I have tried using CATextLayer doesn't work. Is there a way I can achieve this?

cell.messageTextView.text = theText

let textLayer = CATextLayer()
textLayer.string = cell.messageTextView.text
textLayer.contentsScale = 0.2
cell.messageTextView.layer.addSublayer(textLayer)

推荐答案

您可以通过将图层栅格化并缩小其比例来降低图层的质量:

You can drop the quality of the layer by making it rasterized and reducing the scale of it:

let badQualityRatio: CGFloat = 4
textView.layer.shouldRasterize = true
textView.layer.rasterizationScale = UIScreen.main.scale/badQualityRatio

结果:

_{您可以设置 rasterizationScale 0 到 UIScreen.main.scale}

_{you can set the rasterizationScale any number between 0 and UIScreen.main.scale}

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