C# Xamarin iOS在单击时隐藏占位符

我有一个Xamarin iOS应用程序，它有文本字段，所以我想让我的文本字段在单击时隐藏其占位符，而不仅仅是在我开始输入字母时，有可能吗？

有可能，当文本字段开始编辑时，您可以将占位符文本设置为空字符串，如果结束编辑且仍然为空，则将其重置为上一个值。

您可以在文本字段开始编辑时将占位符文本设置为空字符串，如果结束编辑且仍然为空，则将其重置为上一个值。

如下所示：

  string _placeHolderText = "Some Test Placeholder...";

  public override void ViewWillAppear (bool animated)
  {
     base.ViewWillAppear (animated);

     var textView1 = new UITextField (new CGRect (0, 0, UIScreen.MainScreen.Bounds.Width, 100)) {
        Placeholder = _placeHolderText,
        BorderStyle = UITextBorderStyle.Line
     };
     textView1.EditingDidBegin += (object sender, EventArgs e) =>
     {
        textView1.Placeholder = string.Empty;
     };
     textView1.EditingDidEnd += (object sender, EventArgs e) =>
     {
        textView1.Placeholder = _placeHolderText;
     };

     var textView2 = new UITextField (new CGRect (0, textView1.Frame.Bottom, UIScreen.MainScreen.Bounds.Width, 100)) {
        Placeholder = _placeHolderText,
        BorderStyle = UITextBorderStyle.Line
     };

     this.View.AddSubviews (textView1, textView2);
  }

如下所示：

  string _placeHolderText = "Some Test Placeholder...";

  public override void ViewWillAppear (bool animated)
  {
     base.ViewWillAppear (animated);

     var textView1 = new UITextField (new CGRect (0, 0, UIScreen.MainScreen.Bounds.Width, 100)) {
        Placeholder = _placeHolderText,
        BorderStyle = UITextBorderStyle.Line
     };
     textView1.EditingDidBegin += (object sender, EventArgs e) =>
     {
        textView1.Placeholder = string.Empty;
     };
     textView1.EditingDidEnd += (object sender, EventArgs e) =>
     {
        textView1.Placeholder = _placeHolderText;
     };

     var textView2 = new UITextField (new CGRect (0, textView1.Frame.Bottom, UIScreen.MainScreen.Bounds.Width, 100)) {
        Placeholder = _placeHolderText,
        BorderStyle = UITextBorderStyle.Line
     };

     this.View.AddSubviews (textView1, textView2);
  }