UITextField文本居右时空格显示异常bug修复

废话不多说, 直接上解决方案

1. 给输入框的editingChanged事件绑定一个方法.

self.textField.addTarget(self, action: #selector(textfieldEditChanged(textfield:)), for: .editingChanged)

2. 方法内调用解决方案的关键代码.

@objc func textfieldEditChanged(textfield: UITextField) {
    textField.fixRightAlignmentBug()
}

3. 核心代码, 思路, 替换普通空格为Unicode的空格(由于给输入框的text更新赋值, 所以要处理了一下光标位置).

extension UITextField {
    func fixRightAlignmentBug() {
        guard self.textAlignment == .right, let text = self.text, let selectedRange = self.selectedTextRange else {
            return
        }
        let tempRange = NSRange.init(location: self.offset(from: self.beginningOfDocument, to: selectedRange.start), length: 0)
        guard let star = self.position(from: self.beginningOfDocument, offset: tempRange.location), let end = self.position(from: star, offset: tempRange.length) else {
            return
        }
        self.text = text.replacingOccurrences(of: " ", with: "\u{00a0}")
        self.selectedTextRange = self.textRange(from: star, to: end)
    }
}