【发布时间】：2013-12-18 07:28:25
【问题描述】：
我是 Xna 的新手，我正在尝试制作 rpg。我构建了我的游戏并在我的主游戏类中收到了一个错误。我的代码的 Draw 方法出现错误。我不习惯使用 switch 语句，我不确定制作一个的正确方法是什么。我可以采取哪些步骤来解决我的错误？谢谢。
错误：
上线：“switch(activeScreen)”
switch 表达式或 case 标签必须是 bool、char、string、 整数、枚举或对应的可空类型
游戏类：
public class Game1 : Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
SpriteFont font;
KeyboardState keyboardState;
KeyboardState oldKeyboardState;
GameScreen activeScreen;
StartScreen startScreen;
ActionScreen actionScreen;
CharScreen charScreen;
ClassScreen classScreen;
GenderScreen genderScreen;
Vector2 charPosition = new Vector2(0, 0);
Texture2D charSprite;
int charHorizSpeed = 1;
int charVertSpeed = 1;
Texture2D logoTexture;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
graphics.IsFullScreen = false;
oldKeyboardState = Keyboard.GetState();
}
protected override void Initialize()
{
base.Initialize();
}
protected override void LoadContent()
{
spriteBatch = new SpriteBatch(GraphicsDevice);
charSprite = this.Content.Load<Texture2D>("charSprite");
//create new instance of the startScreen
startScreen = new StartScreen(
this,
spriteBatch,
//loads the font to the screen
font = Content.Load<SpriteFont>("menufont"),
//loads the image to the screen
Content.Load<Texture2D>("RPGLogo"));
//adds the screen to components
Components.Add(startScreen);
//startScreen.Hide();
//creates new instance the actionScreen
actionScreen = new ActionScreen(
this,
spriteBatch,
Content.Load<Texture2D>("tileMap"),
Content.Load<Texture2D>("character"),
charSprite = Content.Load<Texture2D>("charSprite"));
//adds the screen to components
Components.Add(actionScreen);
//actionScreen.Hide();
activeScreen.Hide();
activeScreen = startScreen;
activeScreen.Show();
charScreen = new CharScreen(
this,
spriteBatch,
charSprite = Content.Load<Texture2D>("charSprite"),
font = Content.Load<SpriteFont>("menufont"));
Components.Add(charScreen);
//charScreen.Hide ();
activeScreen.Hide();
activeScreen = charScreen;
activeScreen.Show();
classScreen = new ClassScreen(
this,
spriteBatch,
charSprite = Content.Load<Texture2D>("charSprite"),
font = Content.Load<SpriteFont>("menufont"));
Components.Add(classScreen);
activeScreen.Hide();
activeScreen = classScreen;
activeScreen.Show();
}
protected override void Update(GameTime gameTime)
{
//get hte current state of the keyboard
keyboardState = Keyboard.GetState();
UpdateSprite(gameTime);
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
//checks if instances are the same
if (activeScreen == startScreen)
{
//checks if enter key was pressed
if (CheckKey(Keys.Enter))
{
//if the selected index is on the first item (start game), the current active screen will hide adn it will be switched to the action screen
if (startScreen.SelectedIndex == 0)
{
activeScreen.Hide();
activeScreen = actionScreen;
activeScreen.Show();
}
//if the selected index is on the second item (exit) the game will exit
if (startScreen.SelectedIndex == 1)
{
this.Exit();
}
}
}
if (activeScreen == charScreen)
{
if (CheckKey(Keys.Enter))
{
if (charScreen.SelectedIndex == 0)
{
activeScreen.Hide();
activeScreen = classScreen;
activeScreen.Show();
//create a drop down menu for character class options/pop up?
}
}
if (CheckKey(Keys.Enter))
{
if (charScreen.SelectedIndex == 1)
{
activeScreen.Hide();
activeScreen = genderScreen;
activeScreen.Show();
}
}
}
if (activeScreen == classScreen)
{
if (CheckKey(Keys.Enter))
{
if (classScreen.SelectedIndex == 0)
{
//call warior class
}
if (classScreen.SelectedIndex == 1)
{
//call mage class
}
if (classScreen.SelectedIndex == 2)
{
//call ranger class
}
}
}
if (activeScreen == genderScreen)
{
if (CheckKey(Keys.Enter))
{
if (genderScreen.SelectedIndex == 0)
{
//call gender class (male)
}
if (genderScreen.SelectedIndex == 1)
{
//call gender class (female)
}
}
}
base.Update(gameTime);
oldKeyboardState = keyboardState;
}
private bool CheckKey(Keys theKey)
{
//returns if the key was pressed in the last frame
return keyboardState.IsKeyUp(theKey) &&
oldKeyboardState.IsKeyDown(theKey);
}
private void DrawStartScreen()
{
spriteBatch.DrawString(font, "Vengence In Albion", new Vector2(20, 45), Color.White);
}
private void DrawCharScreen()
{
spriteBatch.DrawString(font, "Character Selection", new Vector2(20, 45), Color.White);
spriteBatch.Draw(charSprite, charPosition, Color.White);
}
private void DrawClassScreen()
{
spriteBatch.DrawString(font, "Choose your Class", new Vector2(20, 45), Color.White);
}
private void DrawGenderScreen()
{
spriteBatch.DrawString(font, "Choose a gender", new Vector2(20, 45), Color.White);
}
private void UpdateSprite(GameTime gameTime)
{
//move the sprite by speed
KeyboardState newState = Keyboard.GetState();
int MaxX = Window.ClientBounds.Width - charSprite.Width;
int MaxY = Window.ClientBounds.Height - charSprite.Height;
int MinX = 0;
int MinY = 0;
if (newState.IsKeyDown(Keys.Left))
{
// Move left
charHorizSpeed = -1;
}
if (newState.IsKeyDown(Keys.Right))
{
// Move left
charHorizSpeed = 1;
}
if (newState.IsKeyDown(Keys.Up))
{
// Move left
charVertSpeed = -1;
}
if (newState.IsKeyDown(Keys.Down))
{
// Move left
charVertSpeed = 1;
}
if (charPosition.X > MaxX)
{
charHorizSpeed *= -1;
charPosition.X = MaxX;
}
else if (charPosition.X < MinX)
{
charHorizSpeed *= -1;
charPosition.X = MinX;
}
if (charPosition.Y > MaxY)
{
charVertSpeed *= -1;
charPosition.Y = MaxY;
}
else if (charPosition.Y < MinY)
{
charVertSpeed *= -1;
charPosition.Y = MinY;
}
oldKeyboardState = keyboardState;
}
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.DarkSlateBlue);
spriteBatch.Begin();
switch (activeScreen)
{
case activeScreen.startScreen:
DrawStartScreen();
StartScreen();
break;
case activeScreen.charScreen:
DrawCharScreen();
CharScreen();
break;
case activeScreen.actionScreen:
//draw map
break;
case activeScreen.classScreen:
DrawClassScreen();
ClassScreen();
break;
case activeScreen.genderScreen:
DrawGenderScreen();
GenderScreen();
break;
}
base.Draw(gameTime);
spriteBatch.End();
}
}
【问题讨论】：
-
下次尝试只发布相关代码，而不是全班。
标签： c# xna switch-statement