学习笔记30（手把手教用XNA开发WINPHONE7游戏4）

XNA Game Studio游戏输入

昨天的双11让人感触颇多，幸好有http://winphone.us/和博客园还有技术陪伴我，还有很多园子里的朋友，大家一定不要放弃自己的梦想。

在这个环节，你将为游戏添加输入部分。对于windows Phone手机，他的输入主要是通过触摸板或者重力感应。由于Windows Phone模拟器不提供重力感应，我们提供了一个通过键盘来模拟重力感应的解决方案。这个只供模拟设备测试用，不能在真机上使用。

1.添加Microsoft.Device.Sensors程序集的引用。

图1

Adding a reference to the Microsoft.Devices.Sensors assembly

Note:要添加引用，在解决方案资源管理器中的AlienGame项目下，右键点击References：

2.打开GameplayScreen.cs（如果没有打开的话）.

3.添加如下命名申请:

(Code Snippet –Game Development with XNA– Gameplay Screen – more using statements)

C#

usingMicrosoft.Xna.Framework.Input;

usingMicrosoft.Xna.Framework.Input.Touch;

usingMicrosoft.Devices.Sensors;

4.添加附加的类变量用以保存触摸和加速度计状态：

(Code Snippet –Game Development with XNA– Gameplay Screen – more class variables)

C#

//Input Members

AccelerometerReadingEventArgsaccelState;

TouchCollectiontouchState;

AccelerometerAccelerometer;

5.在构造函数添加如下代码，初始化重力感应:

(Code Snippet –Game Development with XNA– Gameplay Screen – Accelerometer Initialization)

C#

Accelerometer =newAccelerometer();

if(Accelerometer.State ==SensorState.Ready)

{

Accelerometer.ReadingChanged += (s, e) =>

{

accelState = e;

};

Accelerometer.Start();

}

6.创建GameplayScreen类中的"输入"区域:

C#

#regionInput

#endregion

7.在“Input”区域给基类的HandleInput方法添加一个override，此方法将读取当前用户的输入数据，并在之后根据游戏中变化作出响应。

Note:在仿真设备中，鼠标点击将被认为是触摸或者键盘输入。但是使用真机的时候，键盘输入是不会发生的。

(Code Snippet –Game Development with XNA– Gameplan Screen – HandleInput method)

C#

/// <summary>

///Input helper method provided by GameScreen.Packages up the various input

///values for ease of use.Here it checks for pausing and handles controlling

///the player's tank.

/// </summary>

/// <param name="input">The state of the gamepads</param>

publicoverridevoidHandleInput(InputStateinput)

{

if(input ==null)

thrownewArgumentNullException("input");

if(input.PauseGame)

{

if(gameOver ==true)

finishCurrentGame();

}

else

{

touchState =TouchPanel.GetState();

boolbuttonTouched =false;

//interpret touch screen presses

foreach(TouchLocationlocationintouchState)

{

switch(location.State)

{

caseTouchLocationState.Pressed:

buttonTouched =true;

break;

caseTouchLocationState.Moved:

break;

caseTouchLocationState.Released:

break;

}

}

floatmovement = 0.0f;

if(accelState !=null)

{

if(Math.Abs(accelState.X) > 0.10f)

{

if(accelState.X > 0.0f)

movement = 1.0f;

else

movement = -1.0f;

}

}

//TODO: Update player Velocity over X axis #1

//This section handles tank movement.We only allow one "movement" action

//to occur at once so that touchpad devices don't get double hits.

KeyboardStatekeyState =Keyboard.GetState();

if(input.CurrentGamePadStates[0].DPad.Left == ButtonState.Pressed || keyState.IsKeyDown(Keys.Left))

{

//TODO: Update player velocity over X axis #2

}

elseif(input.CurrentGamePadStates[0].DPad.Right == ButtonState.Pressed || keyState.IsKeyDown(Keys.Right))

{

//TODO: Update player velocity over X axis #3

}

else

{

//TODO: Update player velocity over X axis #4

}

// B button, or pressing on the upper half of the pad or space on keyboard or touching the touch panel fires the weapon.

if(input.CurrentGamePadStates[0].IsButtonDown(Buttons.B) || input.CurrentGamePadStates[0].IsButtonDown(Buttons.A) || input.CurrentGamePadStates[0].ThumbSticks.Left.Y > 0.25f ||

keyState.IsKeyDown(Keys.Space) || buttonTouched)

{

if(!gameOver)

{

//TODO: Fire the bullet

}

elseif(gameOver)

finishCurrentGame();

}

}

}

8.添加Helper方法来完成游戏:

(Code Snippet –Game Development with XNA– Gameplay Screen – finishCurrentGame method)

C#

privatevoid finishCurrentGame()

{

foreach(GameScreenscreeninScreenManager.GetScreens())

screen.ExitScreen();

ScreenManager.AddScreen(newBackgroundScreen());

ScreenManager.AddScreen(newMainMenuScreen());

}

9.编译应用程序。

在此部分的过程中，您创建一个游戏的输入处理子系统。它将在创建游戏逻辑的下一个任务中使用。

下一篇就是最后一篇了，你的游戏就要出现了：）