How to working with Android Widgets? Like EditText or Button...

In my game I have to let player input some double byte character, So I think use Android Widgets like EditText and Button is a good choice.
This is my View class:

public class TextInputView : LinearLayout
{
Android.Widget.Button _bt;
Android.Widget.EditText _te;

    public TextInputView(Context context, View v)
        : base(context)
    {
        _bt = new Android.Widget.Button(context);
        _te = new Android.Widget.EditText(context);

        _bt.Text = "OK";
        _bt.Click += delegate
        {
            Game1.Activity.SetContentView(v);
        };
        AddView(_te);
        AddView(_bt);
    }

}

In my Activity class:
public class Activity1 : Microsoft.Xna.Framework.AndroidGameActivity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);

        Game1.Activity = this;
        var g = new Game1();
        View gameView = g.Window;
        g.Run();

        TextInputView inputView = new TextInputView(this,gameView);
        Game1.View = inputView;
        SetContentView(gameView);
    }
}

In my Game1 class, I use SetContentView(Game1.View);
It’s works fine, TextInputView shows up, but when I click button want switch back to game, I got a black screen.

Solved by myself. When Game class get back all texture was delected, I have to reload it.