如何通过快速点击按钮来动态更改文本视图中的字体？

Question

我创建了如下所示的文本视图，并添加了键盘按钮供用户更改字体。它正在工作，但是它更改了整个文本的字体，但是我只想在单击按钮后更改字体。您可以帮忙吗？

   func setKeyboard() { // this is for keyboard button

    let bar = UIToolbar()

    let flex = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: self, action: nil)

     let font = UIBarButtonItem(image: UIImage(named: "icons8-image-80"), style: .plain, target: self, action: #selector(fontTapped))

bar.barTintColor = UIColor(displayP3Red: 30/255, green: 30/255, blue: 30/255, alpha: 1)
bar.sizeToFit()

    writePost.inputAccessoryView = bar

}

// and this one is fontTapped function

   @objc func fontTapped() {

    if fontTag == 0 {
       let attributedText = NSMutableAttributedString(string: writePost.text, attributes: [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 12)])
         writePost.attributedText = attributedText
        fontTag = 1

    } else {

        writePost.font = UIFont(name: "AvenirNext-DemiBoldItalic", size: 16)
        fontTag = 0
}
}

Answer 1

您将像这样使用UITextField的attributedText属性：

https://medium.com/swift-india/multiple-font-style-for-uilable-text-using-nsattributed-string-3f121036a533

并且可能在UITextFieldDelegate的shouldChangeCharactersInRange（）中构建您的属性字符串，以便更改传入字符的字体。

How shouldChangeCharactersInRange works in Swift?