         }
         return superReturnValue
     }
-    
+
     override func paste(_ sender: Any?) {
         var shouldCallSuper = true
         if let pasteBlock = self.pasteBlock {

            }
        }
    }
    
    override var contentOffset: CGPoint {
        get {
            return super.contentOffset

        self.placeholder = placeholder // 触发文字样式的更新
    }

    // MARK: - UIResponderStandardEditActions

    override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        let superReturnValue = super.canPerformAction(action, withSender: sender)
        if action == #selector(paste(_:)) && canPerformPasteActionBlock != nil {
