前文简单介绍了Android中SurfaceView的基本使用，本文就来介绍一下SurfaceView与多线程的混搭。SurfaceView与多线程混搭，是为了防止动画闪烁而实现的一种多线程应用。android的多线程用法与JAVA的多线程用法完全一样，本文不做多线程方面的介绍了。直接讲解SurfaceView与多线程的混合使用，即开一条线程专门读取图片，另外一条线程专门绘图。

本文程序运行截图如下，左边是开单个线程读取并绘图，右边是开两个线程，一个专门读取图片，一个专门绘图：

对比一下可以看出，右边动画的帧速明显比左边的快，左右两者都没使用Thread.sleep()。为什么要开两个线程一个读一个画，而不去开两个线程像左边那样都“边读边画”呢？因为SurfaceView每次绘图都会锁定Canvas,也就是说同一片区域这次没画完下次就不能画，因此要提高动画播放的效率，就得开一条线程专门画图，开另外一条线程做预处理的工作。

main.xml的源码如下：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical"> <LinearLayout android:id="@+id/LinearLayout01" android:layout_width="wrap_content" android:layout_height="wrap_content"> <Button android:id="@+id/Button01" android:layout_width="wrap_content"  android:layout_height="wrap_content" android:text="单个独立线程"></Button> <Button android:id="@+id/Button02" android:layout_width="wrap_content"  android:layout_height="wrap_content" android:text="两个独立线程"></Button> </LinearLayout> <SurfaceView android:id="@+id/SurfaceView01" android:layout_width="fill_parent" android:layout_height="fill_parent"></SurfaceView></LinearLayout>

Java程序的源码如下：

package com.testSurfaceView;import java.lang.reflect.Field;import java.util.ArrayList;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.Rect;import android.os.Bundle;import android.util.Log;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import android.widget.Button;public class testSurfaceView extends Activity { /** Called when the activity is first created. */ Button btnSingleThread, btnDoubleThread; SurfaceView sfv; SurfaceHolder sfh; ArrayList<Integer> imgList = new ArrayList<Integer>(); int imgWidth, imgHeight; Bitmap bitmap;//独立线程读取，独立线程绘图 @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btnSingleThread = (Button) this.findViewById(R.id.Button01); btnDoubleThread = (Button) this.findViewById(R.id.Button02); btnSingleThread.setOnClickListener(new ClickEvent()); btnDoubleThread.setOnClickListener(new ClickEvent()); sfv = (SurfaceView) this.findViewById(R.id.SurfaceView01); sfh = sfv.getHolder(); sfh.addCallback(new MyCallBack());// 自动运行surfaceCreated以及surfaceChanged } class ClickEvent implements View.OnClickListener { @Override public void onClick(View v) {  if (v == btnSingleThread) {  new Load_DrawImage(0, 0).start();//开一条线程读取并绘图  } else if (v == btnDoubleThread) {  new LoadImage().start();//开一条线程读取  new DrawImage(imgWidth + 10, 0).start();//开一条线程绘图  } } } class MyCallBack implements SurfaceHolder.Callback { @Override public void surfaceChanged(SurfaceHolder holder, int format, int width,  int height) {  Log.i("Surface:", "Change"); } @Override public void surfaceCreated(SurfaceHolder holder) {  Log.i("Surface:", "Create");  // 用反射机制来获取资源中的图片ID和尺寸  Field[] fields = R.drawable.class.getDeclaredFields();  for (Field field : fields) {  if (!"icon".equals(field.getName()))// 除了icon之外的图片  {   int index = 0;   try {   index = field.getInt(R.drawable.class);   } catch (IllegalArgumentException e) {   // TODO Auto-generated catch block   e.printStackTrace();   } catch (IllegalAccessException e) {   // TODO Auto-generated catch block   e.printStackTrace();   }   // 保存图片ID   imgList.add(index);  }  }  // 取得图像大小  Bitmap bmImg = BitmapFactory.decodeResource(getResources(),   imgList.get(0));  imgWidth = bmImg.getWidth();  imgHeight = bmImg.getHeight(); } @Override public void surfaceDestroyed(SurfaceHolder holder) {  Log.i("Surface:", "Destroy"); } } /* * 读取并显示图片的线程 */ class Load_DrawImage extends Thread { int x, y; int imgIndex = 0; public Load_DrawImage(int x, int y) {  this.x = x;  this.y = y; } public void run() {  while (true) {  Canvas c = sfh.lockCanvas(new Rect(this.x, this.y, this.x   + imgWidth, this.y + imgHeight));  Bitmap bmImg = BitmapFactory.decodeResource(getResources(),   imgList.get(imgIndex));  c.drawBitmap(bmImg, this.x, this.y, new Paint());  imgIndex++;  if (imgIndex == imgList.size())   imgIndex = 0;  sfh.unlockCanvasAndPost(c);// 更新屏幕显示内容  } } }; /* * 只负责绘图的线程 */ class DrawImage extends Thread { int x, y; public DrawImage(int x, int y) {  this.x = x;  this.y = y; } public void run() {  while (true) {  if (bitmap != null) {//如果图像有效   Canvas c = sfh.lockCanvas(new Rect(this.x, this.y, this.x    + imgWidth, this.y + imgHeight));   c.drawBitmap(bitmap, this.x, this.y, new Paint());   sfh.unlockCanvasAndPost(c);// 更新屏幕显示内容  }  } } }; /* * 只负责读取图片的线程 */ class LoadImage extends Thread { int imgIndex = 0; public void run() {  while (true) {  bitmap = BitmapFactory.decodeResource(getResources(),   imgList.get(imgIndex));  imgIndex++;  if (imgIndex == imgList.size())//如果到尽头则重新读取   imgIndex = 0;  } } };}

希望本文所述示例能对大家进行Android的SurfaceView与多线程的混搭编程有所帮助。