c#, xna, wp7 touch screen not working

Question

I am making a wp7 application and my touch screen doesnt seem to work. The code that i have wrote is below

protected override void Update(GameTime gameTime)
{
    TouchCollection touches = TouchPanel.GetState();
    if (touches.Count > 0 && touches[0].State == TouchLocationState.Pressed)
    {
        SpriteFont font = Content.Load<SpriteFont>("Font");
        Point touchPoint = new Point((int)touches[0].Position.X, (int)touches[0].Position.Y);
        spriteBatch.Begin();
        spriteBatch.DrawString(font, "hello ", new Vector2(touchPoint.X, touchPoint.Y), Color.White);
        spriteBatch.End();

        while (TouchPanel.IsGestureAvailable)
        {
            GestureSample gesture = TouchPanel.ReadGesture();
            switch (gesture.GestureType)
            {
                case GestureType.Tap:
                case GestureType.DoubleTap:
                    spriteBatch.Begin();
                    spriteBatch.DrawString(font, " ", new Vector2(touchPoint.X, touchPoint.Y), Color.White);
                    spriteBatch.End();
                    break;
            }
        }
    }
    base.Update(gameTime);
}

Answer 1

The problem can be that you trying to draw something in Update method. Draw method is for drawing . So in your case you draw something in Update method next you draw background in Draw method so you overried your text.

protected override void Draw(GameTime gameTime)
{
    GraphicsDevice.Clear(Color.CornflowerBlue);
    // overriding here
    ... draw background

    // *draw your text should be here
    base.Draw(gameTime);
}

So the solution is to move "spriteBatch.DrawString(...);" to Draw method and put it below background in your code or add depth parameter to draw methods.

Answer 2

looking at your code now, nothing seems wrong, but have you tried stepping through it? I see that tapping or double tapping do the same thing, but maybe something is being hung up.

The first thing that I thought of though, is your XAML. Do you have a control or something over top everything else? This could be catching you gestures.

If neither works, could you post more information?