c# - Xamarin iOS 在点击时隐藏占位符

Question

我有一个 Xamarin iOS 应用程序，它有文本字段，所以我希望我的文本字段在单击时隐藏它们的占位符，而不仅仅是在我开始输入字母时，这可能吗？

Answer 1

类似下面的内容:

  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);
  }