XNA / C＃2D播放器动画问题

Question

My friend and I have decided to make a game for ourselves. It is going with a Pokemon and the old Harvest Moon graphics style. I have was doing some testing with animation and I got it to work. My player Sprite Sheet has eight images (2 for each direction).

But, When I hold down the Up arrow key and Left or Right or Down arrow keys and Left or Right it is trying to do both animations at once. I know that there must be a way to solve this I just need someone to tell me how.

This is my Animation Class that I have for my Player:

public class Animation
{
    Texture2D texture;
    Rectangle rectangle;
    public Vector2 position;
    Vector2 origin;
    Vector2 velocity;

    int currentFrame;
    int frameHeight;
    int frameWidth;

    float timer;
    float interval = 75;

    public Animation(Texture2D newTexture, Vector2 newPosition, int newFrameHeight, int newFrameWidth)
    {
        texture = newTexture;
        position = newPosition;
        frameWidth = newFrameWidth;
        frameHeight = newFrameHeight;
    }

    public void Update(GameTime gameTime)
    {
        rectangle = new Rectangle(currentFrame * frameWidth, 0, frameWidth, frameHeight);
        origin = new Vector2(rectangle.Width / 2, rectangle.Height / 2);
        position = position + velocity;

        // Comment Out For Camera!!!!
        if (position.X <= 0 + 10) position.X = 0 + 10;
        if (position.X >= 1920 - rectangle.Width + 5) position.X = 1920 - rectangle.Width + 5;
        if (position.Y <= 0 + 10) position.Y = 0 + 10;
        if (position.Y >= 1080 - rectangle.Height + 7) position.Y = 1080 - rectangle.Height + 7;

        if (Keyboard.GetState().IsKeyDown(Keys.Right))
        {
            AnimateRight(gameTime);
            velocity.X = 2;
        }
        else if (Keyboard.GetState().IsKeyDown(Keys.Left))
        {
            AnimateLeft(gameTime);
            velocity.X = -2;
        }
        else velocity = Vector2.Zero;

        if (Keyboard.GetState().IsKeyDown(Keys.Up))
        {
            AnimateUp(gameTime);
            velocity.Y = -2;
        }
        if (Keyboard.GetState().IsKeyDown(Keys.Down))
        {
            AnimateDown(gameTime);
            velocity.Y = 2;
        }
    }

    public void AnimateRight(GameTime gameTime)
    {
            timer += (float)gameTime.ElapsedGameTime.TotalMilliseconds / 2;
            if (timer > interval)
            {
                currentFrame++;
                timer = 0;
                if (currentFrame > 1)
                    currentFrame = 0;
            }
    }

    public void AnimateLeft(GameTime gameTime)
    {
            timer += (float)gameTime.ElapsedGameTime.TotalMilliseconds / 2;
            if (timer > interval)
            {
                currentFrame++;
                timer = 0;
                if (currentFrame > 3 || currentFrame < 2)
                    currentFrame = 2;
            }
    }

    public void AnimateUp(GameTime gameTime)
    {
            timer += (float)gameTime.ElapsedGameTime.TotalMilliseconds / 2;
            if (timer > interval)
            {
                currentFrame++;
                timer = 0;
                if (currentFrame > 5 || currentFrame < 4)
                    currentFrame = 4;
            }
    }

    public void AnimateDown(GameTime gameTime)
    {
            timer += (float)gameTime.ElapsedGameTime.TotalMilliseconds / 2;
            if (timer > interval)
            {
                currentFrame++;
                timer = 0;
                if (currentFrame > 7 || currentFrame < 6)
                    currentFrame = 6;
            }
    }

    public void Draw(SpriteBatch spriteBatch)
    {
        spriteBatch.Draw(texture, position, rectangle, Color.White, 0f, origin, 1.0f, SpriteEffects.None, 0);
    }
}

Answer 1

This would allow movement in only one direction at a time (which I believe is what you want if you are following pokemon's game style):

    if (Keyboard.GetState().IsKeyDown(Keys.Right))
    {
        AnimateRight(gameTime);
        velocity.X = 2;
    }
    else if (Keyboard.GetState().IsKeyDown(Keys.Left))
    {
        AnimateLeft(gameTime);
        velocity.X = -2;
    }       
    else if (Keyboard.GetState().IsKeyDown(Keys.Up))
    {
        AnimateUp(gameTime);
        velocity.Y = -2;
    }
    else if (Keyboard.GetState().IsKeyDown(Keys.Down))
    {
        AnimateDown(gameTime);
        velocity.Y = 2;
    }
    else velocity = Vector2.Zero;

If you want to move two directions at once, something like:

    bool animated = false;
    if (Keyboard.GetState().IsKeyDown(Keys.Right))
    {
        AnimateRight(gameTime);
        velocity.X = 2;
        animated = true;
    }
    else if (Keyboard.GetState().IsKeyDown(Keys.Left))
    {
        AnimateLeft(gameTime);
        velocity.X = -2;
        animated = true;
    }    
    else
    {
         velocity.X = 0;
    }  

    if (Keyboard.GetState().IsKeyDown(Keys.Up))
    {
        if(animated == false)
        {   AnimateUp(gameTime); }

        velocity.Y = -2;
    }
    else if (Keyboard.GetState().IsKeyDown(Keys.Down))
    {
        if(animated == false)
        { AnimateDown(gameTime); }
        velocity.Y = 2;
    }
    else velocity.Y = 0;

Answer 2

I know this is kinda old but with this scenario, there is order priority that the player can't control which affect the direction he will be moving if two keys are pressed at the same time. A better solution would be :

velocity = Vector2.Zero;

if (Keyboard.GetState().IsKeyDown(Keys.Right))
    velocity.X += 2;
if (Keyboard.GetState().IsKeyDown(Keys.Left))
    velocity.X -= 2;

if (Keyboard.GetState().IsKeyDown(Keys.Up))
    velocity.Y -= 2;
if (Keyboard.GetState().IsKeyDown(Keys.Down))
    velocity.Y += 2;

if (velocity.X > 0)
    AnimateRight(gameTime);
else if (velocity.X < 0)
    AnimateLeft(gameTime);

// Animate Up/Down only if Left/Right does not... 
// not sure if needed but will follow the style.
if (velocity.X == 0) 
{
    if (velocity.Y > 0)
        AnimateDown(gameTime);
    else if (velocity.Y < 0)
        AnimateUp(gameTime);
}

This way, we separate the input and the logic, which makes things much clearer and we doesn't put priority over certain input (xept for the up/down... but w/e) If a player tries to go Left and Right at the same time, the movement will just be canceled.