Android游戏开发中绘制游戏触摸轨迹的曲线图

/** 创建曲线画笔 **/ 
mPaint = new Paint(); 
mPaint.setColor(Color.BLACK); 
/**设置画笔抗锯齿**/ 
mPaint.setAntiAlias(true); 
/**画笔的类型**/ 
mPaint.setStyle(Paint.Style.STROKE); 
/**设置画笔变为圆滑状**/ 
mPaint.setStrokeCap(Paint.Cap.ROUND); 
/**设置线的宽度**/ 
mPaint.setStrokeWidth(5); 

@Override 
public boolean onTouchEvent(MotionEvent event) { 
 /** 拿到触摸的状态 **/ 
 int action = event.getAction(); 
 float x = event.getX(); 
 float y = event.getY(); 
 switch (action) { 
 // 触摸按下的事件 
 case MotionEvent.ACTION_DOWN: 
 /**设置曲线轨迹起点 X Y坐标**/ 
 mPath.moveTo(x, y); 
 break; 
 // 触摸移动的事件 
 case MotionEvent.ACTION_MOVE: 
 /**设置曲线轨迹**/ 
 //参数1 起始点X坐标 
 //参数2 起始点Y坐标 
 //参数3 结束点X坐标 
 //参数4 结束点Y坐标 
 mPath.quadTo(mposX, mposY, x, y); 
 break; 
 // 触摸抬起的事件 
 case MotionEvent.ACTION_UP: 
 /**按键抬起后清空路径轨迹**/ 
 mPath.reset(); 
 break; 
 } 
 //记录当前触摸X Y坐标 
 mposX = x; 
 mposY = y; 
 return true; 
} 

private void Draw() { 
 /**清空画布**/ 
 mCanvas.drawColor(Color.WHITE); 
 /**绘制曲线**/ 
 mCanvas.drawPath(mPath, mPaint); 
 /**记录当前触点位置**/ 
 mCanvas.drawText("当前触笔 X：" + mposX, 0, 20,mTextPaint); 
 mCanvas.drawText("当前触笔 Y：" + mposY, 0, 40,mTextPaint); 
} 

import android.app.Activity; 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Path; 
import android.os.Bundle; 
import android.view.MotionEvent; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 
import android.view.Window; 
import android.view.WindowManager; 
import android.view.SurfaceHolder.Callback; 
public class SurfaceViewAcitvity extends Activity { 
 MyView mAnimView = null; 
 @Override 
 public void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 // 全屏显示窗口 
 requestWindowFeature(Window.FEATURE_NO_TITLE); 
 getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
  WindowManager.LayoutParams.FLAG_FULLSCREEN); 
 // 显示自定义的游戏View 
 mAnimView = new MyView(this); 
 setContentView(mAnimView); 
 } 
 public class MyView extends SurfaceView implements Callback,Runnable { 
  /**每50帧刷新一次屏幕**/ 
 public static final int TIME_IN_FRAME = 50; 
 /** 游戏画笔 **/ 
 Paint mPaint = null; 
 Paint mTextPaint = null; 
 SurfaceHolder mSurfaceHolder = null; 
 /** 控制游戏更新循环 **/ 
 boolean mRunning = false; 
 /** 游戏画布 **/ 
 Canvas mCanvas = null; 
 /**控制游戏循环**/ 
 boolean mIsRunning = false; 
 /**曲线方向**/ 
 private Path mPath; 
 private float mposX, mposY; 
 public MyView(Context context) { 
  super(context); 
  /** 设置当前View拥有控制焦点 **/ 
  this.setFocusable(true); 
  /** 设置当前View拥有触摸事件 **/ 
  this.setFocusableInTouchMode(true); 
  /** 拿到SurfaceHolder对象 **/ 
  mSurfaceHolder = this.getHolder(); 
  /** 将mSurfaceHolder添加到Callback回调函数中 **/ 
  mSurfaceHolder.addCallback(this); 
  /** 创建画布 **/ 
  mCanvas = new Canvas(); 
  /** 创建曲线画笔 **/ 
  mPaint = new Paint(); 
  mPaint.setColor(Color.BLACK); 
  /**设置画笔抗锯齿**/ 
  mPaint.setAntiAlias(true); 
  /**画笔的类型**/ 
  mPaint.setStyle(Paint.Style.STROKE); 
  /**设置画笔变为圆滑状**/ 
  mPaint.setStrokeCap(Paint.Cap.ROUND); 
  /**设置线的宽度**/ 
  mPaint.setStrokeWidth(5); 
  /**创建路径对象**/ 
  mPath = new Path(); 
  /** 创建文字画笔 **/ 
  mTextPaint = new Paint(); 
  /**设置颜色**/ 
  mTextPaint.setColor(Color.BLACK); 
  /**设置文字大小**/ 
  mTextPaint.setTextSize(15); 
 } 
 @Override 
 public boolean onTouchEvent(MotionEvent event) { 
  /** 拿到触摸的状态 **/ 
  int action = event.getAction(); 
  float x = event.getX(); 
  float y = event.getY(); 
  switch (action) { 
  // 触摸按下的事件 
  case MotionEvent.ACTION_DOWN: 
  /**设置曲线轨迹起点 X Y坐标**/ 
  mPath.moveTo(x, y); 
  break; 
  // 触摸移动的事件 
  case MotionEvent.ACTION_MOVE: 
  /**设置曲线轨迹**/ 
  //参数1 起始点X坐标 
  //参数2 起始点Y坐标 
  //参数3 结束点X坐标 
  //参数4 结束点Y坐标 
  mPath.quadTo(mposX, mposY, x, y); 
  break; 
  // 触摸抬起的事件 
  case MotionEvent.ACTION_UP: 
  /**按键抬起后清空路径轨迹**/ 
  mPath.reset(); 
  break; 
  } 
  //记录当前触摸X Y坐标 
  mposX = x; 
  mposY = y; 
  return true; 
 } 
 private void Draw() { 
  /**清空画布**/ 
  mCanvas.drawColor(Color.WHITE); 
  /**绘制曲线**/ 
  mCanvas.drawPath(mPath, mPaint); 
  /**记录当前触点位置**/ 
  mCanvas.drawText("当前触笔 X：" + mposX, 0, 20,mTextPaint); 
  mCanvas.drawText("当前触笔 Y：" + mposY, 0, 40,mTextPaint); 
 } 
 @Override 
 public void surfaceChanged(SurfaceHolder holder, int format, int width, 
  int height) { 
 } 
 @Override 
 public void surfaceCreated(SurfaceHolder holder) { 
  /**开始游戏主循环线程**/ 
  mIsRunning = true; 
  new Thread(this).start(); 
 } 
 @Override 
 public void surfaceDestroyed(SurfaceHolder holder) { 
  mIsRunning = false; 
 } 
 @Override 
 public void run() { 
  while (mIsRunning) { 
  /** 取得更新游戏之前的时间 **/ 
  long startTime = System.currentTimeMillis(); 
  /** 在这里加上线程安全锁 **/ 
  synchronized (mSurfaceHolder) { 
   /** 拿到当前画布 然后锁定 **/ 
   mCanvas = mSurfaceHolder.lockCanvas(); 
   Draw(); 
   /** 绘制结束后解锁显示在屏幕上 **/ 
   mSurfaceHolder.unlockCanvasAndPost(mCanvas); 
  } 
  /** 取得更新游戏结束的时间 **/ 
  long endTime = System.currentTimeMillis(); 
  /** 计算出游戏一次更新的毫秒数 **/ 
  int diffTime = (int) (endTime - startTime); 
  /** 确保每次更新时间为50帧 **/ 
  while (diffTime <= TIME_IN_FRAME) { 
   diffTime = (int) (System.currentTimeMillis() - startTime); 
   /** 线程等待 **/ 
   Thread.yield(); 
  } 
  } 
 } 
 } 
}