[Android实例] android多点触摸demo .

multitouchactivity

java代码  

package com.zhaokai.multitouch;  

import android.app.activity;  

import android.os.bundle;  

import android.view.window;  

import android.view.windowmanager;  

public class multitouchactivity extends activity {  

    /** called when the activity is first created. */  

     /** called when the activity is first created. */  

    @override  

    public void oncreate(bundle savedinstancestate) {  

      super.oncreate(savedinstancestate);            

      //隐藏标题栏            

      requestwindowfeature(window.feature_no_title);            

      //设置成全屏           

      getwindow().setflags(windowmanager.layoutparams.flag_fullscreen,windowmanager.layoutparams.flag_fullscreen);            

      //设置为上面的mtview            

      setcontentview(new mysurfaceview(this));    

    }  

}  

surfaceview类： 

import android.content.context;  

import android.graphics.canvas;  

import android.graphics.color;  

import android.graphics.paint;  

import android.view.motionevent;  

import android.view.surfaceholder;  

import android.view.surfaceholder.callback;  

import android.view.surfaceview;  

public class mysurfaceview extends surfaceview implements callback{  

private static final int max_touchpoints = 10;  

private static final string start_text = "请随便触摸屏幕进行测试";        

private paint textpaint = new paint();        

private paint touchpaints[] = new paint[max_touchpoints];        

private int colors[] = new int[max_touchpoints];           

private int width, height;        

private float scale = 1.0f;  

public mysurfaceview(context context) {  

  super(context);  

  surfaceholder holder = getholder();            

  holder.addcallback(this);            

  setfocusable(true); // 确保我们的view能获得输入焦点            

  setfocusableintouchmode(true); // 确保能接收到触屏事件            

  init();    

public void init(){  

  // 初始化10个不同颜色的画笔            

  textpaint.setcolor(color.white);    

  colors[0] = color.blue;    

  colors[1] = color.red;  

  colors[2] = color.green;  

  colors[3] = color.yellow;  

  colors[4] = color.cyan;  

  colors[5] = color.magenta;  

  colors[6] = color.dkgray;  

  colors[7] = color.white;  

  colors[8] = color.ltgray;  

  colors[9] = color.gray;  

  for(int i=0;i<max_touchpoints;i++){  

   touchpaints[i]=new paint();  

   touchpaints[i].setcolor(colors[i]);  

  }  

@override  

public boolean ontouchevent(motionevent event) {  

  int pointercount=event.getpointercount();  

  if(pointercount>max_touchpoints){  

   pointercount=max_touchpoints;  

  canvas c=getholder().lockcanvas();  

  if(c!=null){  

   c.drawcolor(color.black);  

   if(event.getaction()==motionevent.action_up){  

    // 当手离开屏幕时，清屏  

    c.drawcolor(color.black);  

   }else{  

     // 先在屏幕上画一个十字，然后画一个圆  

    for(int i=0;i<pointercount;i++){  

     //获取一个触点的坐标，然后开始绘制  

     int id=event.getpointerid(i);  

     int x=(int)event.getx(i);  

     int y=(int)event.gety(i);  

     drawcrosshairsandtext(x, y, touchpaints[id], i, id, c);  

     drawcircle(x, y, touchpaints[id],c);  

   }  

   getholder().unlockcanvasandpost(c);  

  return true;  

private void drawcrosshairsandtext(int x, int y, paint paint, int ptr,int id, canvas c) {  

  c.drawline(0, y, width, y, paint);            

  c.drawline(x, 0, x, height, paint);            

  int texty = (int) ((15 + 20 * ptr) * scale);            

  c.drawtext("x" + ptr + "=" + x, 10 * scale, texty, textpaint);            

  c.drawtext("y" + ptr + "=" + y, 70 * scale, texty, textpaint);            

  c.drawtext("id" + ptr + "=" + id, width - 55 * scale, texty, textpaint);     

}    

private void drawcircle(int x, int y, paint paint, canvas c) {  

  c.drawcircle(x, y, 40 * scale, paint);        

public void surfacechanged(surfaceholder holder, int format, int width,  

   int height) {  

   this.width = width;            

   this.height = height;            

   if (width > height){                

    this.scale = width / 480f;            

   } else {  

   this.scale = height / 480f;            

   }            

   textpaint.settextsize(14 * scale);            

   canvas c = getholder().lockcanvas();            

   if (c != null) {              // 背景黑色                

    c.drawcolor(color.black);                

    float twidth = textpaint.measuretext(start_text);                

    c.drawtext(start_text, width / 2 - twidth / 2, height / 2,textpaint);                

    getholder().unlockcanvasandpost(c);            

  }    

public void surfacecreated(surfaceholder holder) {  

  // todo auto-generated method stub  

public void surfacedestroyed(surfaceholder holder) {  

}   

}