XNA Changing Draw When player uses keyboard [closed] - xna

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Would someone be able to give me an example how to change the texture drawn when the user pressed the keyboard ?
Basically I have 5 sprite images stood still, up, down, left, right
My first attempt was to make boolean conditions in the update method such as if keys.left is pressed the rectangle moves left and for the draw method to draw the character moving left, my problem is the texture of him stood still doesnt disappear and overlaps the same when moving in different directions.
I've tried else statements etc but I'm stuck on basic movements.

Answer 1

So this is very pseudo code, but this is a basic approach how to do that
First we create class which contains all our informations about the player. You can add Health, Score etc aswell.
class Player
{
Texture2D Sprite;
Vector2 Position;
Vector2 Velocity;
static const float PlayerSpeed = 5;
}
Important here is the Position (top left of the sprite), the Velocity(the amount of change every second) and the sprite which is just our texture we want to use. Of course it would be better to use only one player texture and modify the source rect accordingly.
Now our input handling.
void OnKeyboard(GameTime aGameTime, KeyArg aKey)
{
if(aKey == Keys.Left)
{
mPlayer.Velocity = new Vector2(-Player.PlayerSpeed, 0);
mPlayer.Sprite = TextureManager.GetTexture("left_player");
}
else if(aKey == Keys.Right)
{
mPlayer.Velocity = new Vector2(Player.PlayerSpeed, 0);
mPlayer.Sprite = TextureManager.GetTexture("right_player");
}
mPlayer.Position += aGameTime.EllapsedMiliseconds * mPlayer.Velocity;
}
Here we just check which key was pressed, modify the velocity and change the current sprite for our player. The final line is the most important one, this modifies the players position using the velocity modified by the elapsed time of the frame. That way you have a steady movement instead despite any frame rate inconsistencies.
void Render()
{
Sprite.Draw(mPlayer.Sprite, mPlayer.Position);
}
Finally the rendering, how to render a sprite should be clear, here you just use the set sprite and the position.
There is a lot of room for improvements, for example minimizing texture switches, handling sprites with alpha, and the most important one proper handling of the keyboard. You need to steadily adjust the position, but depending on how you implement it, the movement might be bound to the key repeat rate, which may not be desired.