iOS开发之TextField禁用粘贴、选择和全选功能

class CustomTextField: UITextField {  /// 是否只是用于显示（禁用粘贴、选择和全选功能）  var displayOnly = false  /// 禁用粘贴  var disablePaste = false  /// 禁用选择  var disableSelect = false  /// 禁用全选  var disableSelectAll = false  override func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {    if displayOnly {      return false    }    if disablePaste && action == #selector(paste(_:)) {      return false    }    if disableSelect && action == #selector(select(_:)) {      return false    }    if disableSelectAll && action == #selector(selectAll(_:)) {      return false    }    return super.canPerformAction(action, withSender: sender)  }}