手写画板android

水深无声 2022-08-07 03:35 226阅读 0赞

package com.qn.game;  
import android.content.Context;  
import android.graphics.Canvas;  
import android.graphics.Color;  
import android.graphics.Paint;  
import android.graphics.PaintFlagsDrawFilter;  
import android.graphics.Path;  
import android.graphics.Paint.Style;  
import android.view.KeyEvent;  
import android.view.MotionEvent;  
import android.view.SurfaceHolder;  
import android.view.SurfaceHolder.Callback;  
import android.view.SurfaceView;  
public class GameView2 extends SurfaceView implements Callback,Runnable\{  
 private Paint paint=null;  
 private SurfaceHolder holder=null;  
 private boolean flag=true;  
 Canvas canvas=null;  
 private Path path;  
 public GameView2(Context context) \{  
  super(context);  
  setFocusable(true);  
  paint=new Paint();  
  path=new Path();  
   holder=this.getHolder();//得到SurfaceHolder对象，SurfaceHolder  
  //就是指向SurfaceView的指针，SurfaceView就相当于电视机SurfaceHolder就相当于指向电视机  
  //的遥控器，以后要就可以通过SurfaceHolder控制SurfaceView  
  holder.addCallback(this);//在SurfaceHolder上面注册一个监听  
   
 \}  
 public void run() \{  
  while(flag)\{  
   drawView();   
   try \{  
    Thread.sleep(50);  
   \} catch (Exception e) \{  
    // TODO Auto-generated catch block  
    e.printStackTrace();  
   \}  
  \}  
 \}  
 int x=0;  
 private void drawView() \{  
        try\{  
   if(holder!=null)\{  
   canvas=holder.lockCanvas();//锁定的面板在这个锁定面板中就可以绘制了，这个地方  
   canvas.setDrawFilter(new PaintFlagsDrawFilter(0,Paint.ANTI\_ALIAS\_FLAG  
     |Paint.FILTER\_BITMAP\_FLAG));  
  //体现二级缓存第地方  
          paint.setColor(Color.GREEN);  
          paint.setStyle(Style.STROKE);  
          paint.setStrokeWidth(5);  
         // canvas.drawCircle(200, 200, x++, paint);  
          canvas.drawPath(path, paint);  
   \}  
  \}catch (Exception e) \{  
   e.printStackTrace();  
  \}  
  finally\{  
   if(canvas!=null)\{  
          holder.unlockCanvasAndPost(canvas);//画好之后解除锁定并且发送，把当前画好的界面发送到View上  
   \}  
  \}  
 \}  
 public void surfaceChanged(SurfaceHolder holder, int format, int width,  
   int height) \{//当前view改变的时候创建的方法。  
   
 \}  
 public void surfaceCreated(SurfaceHolder holder) \{//当前view创建完成后调用的方法  
  new Thread(this).start();  
 \}  
 public void surfaceDestroyed(SurfaceHolder holder) \{//当前view销毁是执行的方法  
  flag=false;  
 \}  
 @Override  
 public boolean onTouchEvent(MotionEvent event) \{  
  switch (event.getAction()) \{//手按下去抬起来的瞬间  
  case MotionEvent.ACTION\_DOWN:  
   path.moveTo(event.getX(), event.getY());  
   break;  
  case MotionEvent.ACTION\_MOVE:  
   path.lineTo(event.getX(), event.getY());  
   break;  
  default:  
   break;  
  \}  
           invalidate();  
  return true;  
 \}  
   
\}