Android轻松画出触摸轨迹

本文实例介绍了android如何画出触摸轨迹的方法，分享给大家供大家参考，具体内容如下

效果图：

实现代码：

package com.android.gameview5;

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.surfaceholder.callback;
import android.view.surfaceview;
import android.view.window;
import android.view.windowmanager;

public class surfaceviewactivity3 extends activity {
  public void oncreate(bundle s){
  super.oncreate(s);
  //全屏显示
  requestwindowfeature(window.feature_no_title);
  getwindow().setflags(windowmanager.layoutparams.flag_fullscreen,
  windowmanager.layoutparams.flag_fullscreen);
  setcontentview(new myview(this));
  }
  public class myview extends surfaceview implements callback,runnable{

  
  public static final int time_in_frame =50;
  
  paint mpaint = null;
  paint mtextpaint = null;
  surfaceholder msurfaceholder = null;
  
  
  boolean mrunning = false;
  
  
  canvas mcanvas = null;
  
  
  private path mpath;
  
  private float mposx,mposy;
  
public myview(context context){
super(context);
this.setfocusable(true);
this.setfocusableintouchmode(true);
  msurfaceholder = this.getholder();
  msurfaceholder.addcallback(this);
  mcanvas = new canvas();
      
  mpaint = new paint();
  mpaint.setcolor(color.black);
  
  
  mpaint.setantialias(true);
  
  mpaint.setstyle(paint.style.stroke);
  
  
  mpaint.setstrokecap(paint.cap.round);
  
  
  mpaint.setstrokewidth(6);
  
  mpath = new path();
  
  
  mtextpaint = new paint();
  
  mtextpaint.setcolor(color.black);
  
  mtextpaint.settextsize(15);
  
}
public boolean ontouchevent(motionevent event){
  int action = event.getaction();
  float x = event.getx();
  float y = event.gety();
  switch(action){
  case motionevent.action_down:
  mpath.moveto(x, y);
  break;
  case motionevent.action_move:
  mpath.quadto(mposx, mposy, x, y);
  break;
  case motionevent.action_up:
  //mpath.reset();
  break;
  }
  //记录当前触摸点得当前得坐标
  mposx = x;
  mposy = y;
return true;
}
private void ondraw(){
mcanvas.drawcolor(color.white);
//绘制曲线
mcanvas.drawpath(mpath, mpaint);
mcanvas.drawtext("当前触笔x："+mposx,0,20,mtextpaint);
mcanvas.drawtext("当前触笔y:"+mposy,0,40,mtextpaint);
}
public void run() {
// todo auto-generated method stub
while(mrunning){
long starttime = system.currenttimemillis();
synchronized(msurfaceholder){
mcanvas = msurfaceholder.lockcanvas();
ondraw();
msurfaceholder.unlockcanvasandpost(mcanvas);
}
long endtime = system.currenttimemillis();
int difftime = (int) (endtime - starttime);
while(difftime<=time_in_frame){
difftime =(int)(system.currenttimemillis()-starttime);
thread.yield();
}
}
}

@override
public void surfacechanged(surfaceholder holder, int format, int width,
int height) {
// todo auto-generated method stub
}

@override
public void surfacecreated(surfaceholder holder) {
mrunning = true;
new thread(this).start();
}

@override
public void surfacedestroyed(surfaceholder holder) {
// todo auto-generated method stub
mrunning = false;
}
  
  }
}

以上就是android轻松画出触摸轨迹的具体方法，希望对大家的学习有所帮助。