android+SurfaceView+path+onTouchEvent画图

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.graphics.Path.FillType;

import android.graphics.Point;

import android.os.Bundle;

import android.view.MotionEvent;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

import android.view.WindowManager;

public class TouchAndSurActivity extends Activity {

   

GameView myView;

Point point=new Point();

Paint paint = new Paint();

Path path = new Path();

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

       getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);//设置全屏显示

        myView = new GameView(this);    

        setContentView(myView);//使其显示视图

    }

    public boolean onTouchEvent(MotionEvent event) {

        // TODO Auto-generated method stub

        myView.OnTouch(event);

        myView.postInvalidate();

        return super.onTouchEvent(event);

}

    

    

public class GameView extends SurfaceView implements SurfaceHolder.Callback {

        SurfaceHolder surfaceHolder;

        

        public GameView(Context context) {

                super(context);

                // TODO Auto-generated constructor stub

                surfaceHolder = this.getHolder();  

                surfaceHolder.addCallback(this);       

                this.setFocusable(true);  

        }

        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

        }

        public void surfaceCreated(SurfaceHolder holder) {

        }

        public void surfaceDestroyed(SurfaceHolder holder) {

        }

        

        public void OnTouch(MotionEvent event){

   

                paint.setColor(Color.RED);

          paint.setStyle(Paint.Style.STROKE);   //关键在于设置这个   ，默认情况下为实心！！
    

          paint.setStrokeWidth(3);//设置线条粗细

            switch (event.getAction()) 

            {

             case MotionEvent.ACTION_DOWN:

             path.moveTo(event.getX(), event.getY()-40);//设置起点

              break;

              

             case MotionEvent.ACTION_MOVE:

             path.lineTo(event.getX(), event.getY()-40);      

             Canvas canvas = surfaceHolder.lockCanvas();

             canvas.drawPath(path, paint);//指定轨迹画图       由于path是多个轮廓叠加在一起，所以可以绘制在一张图上面。越往后，path中包含的轮廓越多！   

             surfaceHolder.unlockCanvasAndPost(canvas);

              break;

              

             case MotionEvent.ACTION_UP:

              break;

              

             default:            

              break;

            }//switch

           

        }//Ontouch

}  //GameView

    

}//TouchAndSurActivity