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[java]
view plain copyimport android.app.Activity;
import android.os.Bundle;
import android.view.Window;
public class Run extends Activity{
DrawView drawView;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
drawView = new DrawView(this);
setContentView(drawView);
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
drawView.resume();//因为可能出现 返回屏幕的情况，这这里调用 来控制 线程，当返回的时候，暂停线程，如果用到设备监听，这样可以节电
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
drawView.pause();
}
}
首先这是这主程序，主要用来启动控制下面(1),(2),程序：
(1)为调用的时候每次保留 canvas到bitmap中，每次刷新的时候继续使用之前的bitmap
（2）为每次 刷新canvas，用白色做背景，在其上面重新画图
（1）：
[java]
view plain copyimport java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Random;
import org.xml.sax.InputSource;
import android.R.color;
import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.Rect;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class DrawView extends SurfaceView implements Runnable{//继承runnable实现线程
//
Thread gameloop= null;
SurfaceHolder surface;
volatile Boolean running= false;
Bitmap bitmap;
Canvas can;
AssetManager assets = null;
BitmapFactory.Options options = null;
public DrawView(Context context) {
super(context);
// TODO Auto-generated constructor stub
surface=getHolder();
assets=context.getAssets();
options=new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
}
public void pause(){
running = false;
while(true){
try {
gameloop.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void resume(){
running = true;
gameloop = new Thread(this);
gameloop.start();
}
Random r=new Random();
boolean flag=true;
Point p=new Point();
@Override
public void run() {
// TODO Auto-generated method stub
int i=0;
while(running){
if(!surface.getSurface().isValid())
continue;
Canvas canvas = surface.lockCanvas();
if(flag==true){
paint.setColor(Color.rgb(r.nextInt(256),r.nextInt(256),r.nextInt(256)));
flag=false;
bitmap=Bitmap.createBitmap(
canvas.getWidth(),canvas.getHeight(),Config.ARGB_8888);
p.x=canvas.getWidth();
p.y=canvas.getHeight();
can=new Canvas();
can.setBitmap(bitmap);
can.drawColor(Color.WHITE);
}
getNext();
canvas.drawBitmap(bitmap, 0,0, paint);
surface.unlockCanvasAndPost(canvas);
try {
Thread.sleep(50);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Paint paint=new Paint();
private void getNext() {
// TODO Auto-generated method stub
paint.setColor(Color.rgb(r.nextInt(256),r.nextInt(256),r.nextInt(256)));
can.drawLine(r.nextInt(p.x), r.nextInt(p.y), r.nextInt(p.x), r.nextInt(p.y), paint);
}
}
在（1）中，我尝试过直接使用 canvas所得到的画布，但是每次都不能得到所想要的前一个画布
测试得到的情况如下：
null null null 一开始有三个为空的canvas，第一个设置的第一个会在 3的位置，但是获得的在第一个的位置，之后每次获得都是当前的三个之前，这样
就无法每次得到之前的canvas，然后在其中画图，我所做的处理是使用一个bitmap，每次将其保存在bitmap中，要画图的时候再从bitmap中提取出来
就相当于用一个bitmap来保存 状态，实质上还是每次 刷新canvas
(2)
[java]
view plain copy//
public class CopyOfDrawView extends SurfaceView implements Runnable{
Thread gameloop= null;
SurfaceHolder surface;
volatile Boolean running= false;
AssetManager assets = null;
BitmapFactory.Options options = null;
Bitmap knight[];
int frame=0;
public CopyOfDrawView(Context context) {
super(context);
// TODO Auto-generated constructor stub
surface=getHolder();
assets=context.getAssets();
options=new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
knight= new Bitmap[8];
try {
for(int i =0;i<8;i++){
String filename= "knight"+String.valueOf(i+1)+".png";//在 assets中放图片实现存8张bitmap在knight中，显示这8张位图就可以实现动态的动画
InputStream input = assets.open(filename);
knight[i]=BitmapFactory.decodeStream(input, null, options);
input.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void pause(){
running = false;
while(true){
try {
gameloop.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void resume(){
running = true;
gameloop = new Thread(this);
gameloop.start();
}
Random r=new Random();
boolean flag=true;
Point p=new Point();
@Override
public void run() {
// TODO Auto-generated method stub
int i=0;
while(running){
if(!surface.getSurface().isValid())
continue;
Canvas canvas = surface.lockCanvas();
canvas.drawColor(Color.WHITE);
canvas.drawBitmap(knight[frame], 0, 0,null);
Rect dest = new Rect(100,0,300,200); //使用 dest得到一个矩形，这个矩形作为bitmap的框，这样就可以实现不同大小的bitmap
canvas.drawBitmap(knight[frame],null, dest, null);
dest = new Rect(200,0,800,600);
canvas.drawBitmap(knight[frame],null, dest, null);//画位图
surface.unlockCanvasAndPost(canvas);
try {
Thread.sleep(50);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
这个是每次都在canvas中重画
