Is it possible to trigger a loop with key input

Question

Ok I need to know if it is possible to trigger a gameloop with a key press? ex code

 if (GamePad.GetState(PlayerIndex.One).Buttons.X == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Up))
        {
            ball.Update();
        }

obviously this is wrong because when I press the up button the ballstarts moving but stops when I release. and yes I looked online and couldn't find anything on this

Answer 1

Yes, make a boolean variable at the start in Game1. Like this:

if (ballStart)
{
    ball.update();
}

Next, go to where you get the input from the user and change the boolean to be true once the key is pressed. eg.

if (player1keyboardState.IsKeyDown(Keys.W))
{
    paddle1.direction.Y = -1;
    ballStart = true;
}

Hope this helps.

Answer 2

This is possible. As for how to do it, there are many ways. The simplest is probably to use a boolean variable. When the input is read, set that variable to true. Have a while loop use that boolean flag as its condition. When you press the button, the flag is set to true, and the loop happens. When you want to end the loop, set the flag to false again.

Again, many ways to do it. But this one is almost trivially simple.