我正在制作一个非常基本的马里奥风格游戏，我希望我的一个平台在屏幕上来回移动。
在我的平台类中，我创建了一个 Update() 方法，然后在我的 Game1 类中调用它。但是，该平台保持静止。我知道代码在前后移动方面是不完整的，但现在我只想让平台移动。
代码：
class Platforms
{
int xCoord;
int yCoord;
int leftLimit;
int rightLimit;
int length;
Rectangle drawPlatformRectangle;
const int width = 20; // until i figure out how to Game1.twoWidthUnits
const int height = 20; // until i figure out how to Game1.twoHeightUnits
Texture2D blockSprite;
Texture2D leftBlockEdgeSprite;
Texture2D rightBlockEdgeSprite;
public Rectangle CollisionRectangle
{
get { return drawPlatformRectangle; }
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="xCoord">X-Coord of upper left-hand corner of platform</param>
/// <param name="yCoord">Y-Coord of upper left-hand corner of platform</param>
/// <param name="length">Length of platform (oneWidthUnits)</param>
/// <param name="blockSprite">sprite</param>
/// <param name="leftBlockEdgeSprite">sprite</param>
/// <param name="rightBlockEdgeSprite">sprite</param>
public Platforms(int xCoord, int yCoord, int length,
Texture2D blockSprite, Texture2D leftBlockEdgeSprite, Texture2D rightBlockEdgeSprite)
{
this.blockSprite = blockSprite;
this.leftBlockEdgeSprite = leftBlockEdgeSprite;
this.rightBlockEdgeSprite = rightBlockEdgeSprite;
this.length = length;
this.xCoord = xCoord;
this.yCoord = yCoord;
//build draw rectangles
this.drawPlatformRectangle = new Rectangle(
xCoord, yCoord, 2* width, 2* height);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="xCoord">X-Coord of upper left-hand corner of platform</param>
/// <param name="yCoord">Y-Coord of upper left-hand corner of platform</param>
/// <param name="length">Length of platform (oneWidthUnits)</param>
/// <param name="blockSprite">sprite</param>
/// <param name="leftBlockEdgeSprite">sprite</param>
/// <param name="rightBlockEdgeSprite">sprite</param>
/// <param name="leftLimit">X-Coord of how far left platform should travel</param>
/// <param name="rightLimit">X-Coord of how far right platform should travel</param>
public Platforms(int xCoord, int yCoord, int length,
Texture2D blockSprite, Texture2D leftBlockEdgeSprite, Texture2D rightBlockEdgeSprite,
int leftLimit, int rightLimit)
{
this.blockSprite = blockSprite;
this.leftBlockEdgeSprite = leftBlockEdgeSprite;
this.rightBlockEdgeSprite = rightBlockEdgeSprite;
this.length = length;
this.xCoord = xCoord;
this.yCoord = yCoord;
this.leftLimit = leftLimit;
this.rightLimit = rightLimit;
//build draw rectangles
this.drawPlatformRectangle = new Rectangle(
xCoord, yCoord, 2 * width, 2 * height);
}
public void Draw(SpriteBatch spriteBatch)
{
// draw the platform
for (int i = xCoord; i < xCoord + (width * length); i += width * 2)
{
drawPlatformRectangle.X = i; drawPlatformRectangle.Y = yCoord;
spriteBatch.Draw(blockSprite, drawPlatformRectangle, Color.White);
}
// draw the grass edges
drawPlatformRectangle.X = xCoord - width*2; drawPlatformRectangle.Y = yCoord;
spriteBatch.Draw(leftBlockEdgeSprite, drawPlatformRectangle, Color.White);
drawPlatformRectangle.X = xCoord + (width * length)+width; drawPlatformRectangle.Y = yCoord;
spriteBatch.Draw(rightBlockEdgeSprite, drawPlatformRectangle, Color.White);
}
public void Update(GameTime gameTime)
{
drawPlatformRectangle.X += 5;
// to do: reverse direction when it reaches limits
}
}
这是 Game1 类：
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
const int WINDOW_WIDTH = 800;
const int WINDOW_HEIGHT = 600;
// game state
GameState gameState = GameState.OpeningMenu;
// menu fields
Texture2D test;
// Level 1 textures list
Texture2D skyBackground;
Texture2D grassTexture;
Texture2D leftGrassTexture;
Texture2D rightGrassTexture;
SpriteFont score;
// Level 1 platforms
Platforms platform1;
Platforms platform2;
Platforms platform3;
Platforms platform4;
Platforms platform5;
Platforms platform6;
Platforms platform7;
Platforms platform8;
Platforms platform9;
// sounds
SoundEffect backgroundSong;
SoundEffectInstance backgroundSongInstance;
// drawing variables
int oneWidthUnit = WINDOW_WIDTH / 40;
int oneHeightUnit = WINDOW_HEIGHT / 30;
//int twoWidthUnits = WINDOW_WIDTH / 20;
//int twoHeightUnits = WINDOW_HEIGHT / 15;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
graphics.PreferredBackBufferWidth = WINDOW_WIDTH;
graphics.PreferredBackBufferHeight = WINDOW_HEIGHT;
IsMouseVisible = true;
}
protected override void Initialize()
{
Window.Title = "Rory's Super Mega Awesome Game of Awesomeness";
base.Initialize();
}
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
// TODO: use this.Content to load your game content here
// Opening Screen Textures
test = Content.Load<Texture2D>("test");
// Load sounds here
backgroundSong = Content.Load<SoundEffect>("Call to Adventure");
backgroundSongInstance = backgroundSong.CreateInstance();
backgroundSongInstance.IsLooped = true;
// Load Level 1 sprite textures here
skyBackground = Content.Load<Texture2D>("skybackground");
//dirtTexture = Content.Load<Texture2D>("dirt");
grassTexture = Content.Load<Texture2D>("grass_top");
leftGrassTexture = Content.Load<Texture2D>("edge_left");
rightGrassTexture = Content.Load<Texture2D>("edge_right");
//create platforms
platform1 = new Platforms(0, 28 * oneHeightUnit, 15, grassTexture, leftGrassTexture, rightGrassTexture);
platform2 = new Platforms(26 * oneWidthUnit, 28 * oneHeightUnit, 14, grassTexture, leftGrassTexture, rightGrassTexture);
platform3 = new Platforms(10 * oneWidthUnit, 23 * oneHeightUnit, 7, grassTexture, leftGrassTexture, rightGrassTexture);
platform4 = new Platforms(18 * oneWidthUnit, 19 * oneHeightUnit, 5, grassTexture, leftGrassTexture, rightGrassTexture);
platform5 = new Platforms(5 * oneWidthUnit, 15 * oneHeightUnit, 9, grassTexture, leftGrassTexture, rightGrassTexture);
platform6 = new Platforms(19 * oneWidthUnit, 11 * oneHeightUnit, 3, grassTexture, leftGrassTexture, rightGrassTexture);
platform7 = new Platforms(23 * oneWidthUnit, 7 * oneHeightUnit, 3, grassTexture, leftGrassTexture, rightGrassTexture);
platform8 = new Platforms(30 * oneWidthUnit, 7 * oneHeightUnit, 7, grassTexture, leftGrassTexture, rightGrassTexture);
platform9 = new Platforms(34 * oneWidthUnit, 14 * oneHeightUnit, 6, grassTexture, leftGrassTexture, rightGrassTexture);
}
protected override void Update(GameTime gameTime)
{
// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
// goes from menu to level 1 when player presses enter
if (gameState == GameState.OpeningMenu && Keyboard.GetState().IsKeyDown(Keys.Enter))
{
gameState = GameState.Play;
backgroundSongInstance.Play();
}
if (gameState == GameState.Play)
{
platform4.Update(gameTime); // ******THIS IS WHERE I'M HAVING THE PROBLEM!********
}
base.Update(gameTime);
}
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
// TODO: Add your drawing code here
spriteBatch.Begin();
// draw opening menu
if (gameState == GameState.OpeningMenu)
{
Rectangle rec = new Rectangle(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT);
spriteBatch.Draw(test, rec, Color.White);
}
// draw level 1
else if (gameState == GameState.Play)
{
DrawScenery();
platform1.Draw(spriteBatch);
platform2.Draw(spriteBatch);
platform3.Draw(spriteBatch);
platform4.Draw(spriteBatch);
platform5.Draw(spriteBatch);
platform6.Draw(spriteBatch);
platform7.Draw(spriteBatch);
platform8.Draw(spriteBatch);
platform9.Draw(spriteBatch);
}
spriteBatch.End();
base.Draw(gameTime);
}
private void DrawScenery()
{
Rectangle backgroundRectangle = new Rectangle(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT);
spriteBatch.Draw(skyBackground, backgroundRectangle, Color.White);
}
}