How to set Placeholder and PlaceHolder Color in Editor Xamarin Forms

Question

How to set Placeholder Text and Placeholder Color in Editor in Xamarin Forms.

It has no default Functiona

Answer 1

Set the placeholder string to your Editor's Text in Xaml Then in Code behind file:

InitializeComponent();

var placeholder = myEditor.Text;

myEditor.Focused += (sender, e) =>
{
     // Set the editor's text empty on focus, only if the place 
     // holder is present
     if (myEditor.Text.Equals(placeholder))
     {
          myEditor.Text = string.Empty;
          // Here You can change the text color of editor as well
          // to active text color
     }
};

myEditor.Unfocused += (sender, e) => 
{
     // Set the editor's text to place holder on unfocus, only if 
     // there is no data entered in editor
    if (string.IsNullOrEmpty(myEditor.Text.Trim()))
    {
        myEditor.Text = placeholder;
        // Here You can change the text color of editor as well
        // to dim text color (Text Hint Color)
    }
};

Answer 2

You will need a custom renderer for that (Here is the Android Custom Renderer) you will need another renderer for iOS:

public class PlaceholderEditor : Editor
{
    public static readonly BindableProperty PlaceholderProperty =
        BindableProperty.Create<PlaceholderEditor, string>(view => view.Placeholder, String.Empty);

    public PlaceholderEditor()
    {
    }

    public string Placeholder
    {
        get
        {
            return (string)GetValue(PlaceholderProperty);
        }

        set
        {
            SetValue(PlaceholderProperty, value);
        }
    }
}

public class PlaceholderEditorRenderer : EditorRenderer
{
    public PlaceholderEditorRenderer()
    {
    }

    protected override void OnElementChanged(
        ElementChangedEventArgs<Editor> e)
    {
        base.OnElementChanged(e);

        if (e.NewElement != null)
        {
            var element = e.NewElement as PlaceholderEditor;
            this.Control.Hint = element.Placeholder;
        }
    }

    protected override void OnElementPropertyChanged(
        object sender,
        PropertyChangedEventArgs e)
    {
        base.OnElementPropertyChanged(sender, e);

        if (e.PropertyName == PlaceholderEditor.PlaceholderProperty.PropertyName)
        {
            var element = this.Element as PlaceholderEditor;
            this.Control.Hint = element.Placeholder;
        }
    }
}

And for the color you may need something like this (Android):

Control.SetHintTextColor(Android.Graphics.Color.White);

There already a thread for this in the Xamarin Forums: https://forums.xamarin.com/discussion/20616/placeholder-editor

And more about Custom Renderers information below: https://developer.xamarin.com/guides/xamarin-forms/custom-renderer/