SurfaceView的特性是：可以在主线程之外的线程中向屏幕绘图上。这样可以避免画图任务繁重的时候造 成主线程阻塞，从而提高了程序的反应速度。在游戏开发中多用到SurfaceView，游戏中的背景、人物、动画等等尽量在画布canvas中画出。
1.案例一
布局文件：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent" android:weightSum="1">
<SurfaceView
android:layout_height="220dip"
android:layout_gravity="center"
android:id="@+id/surface"
android:layout_weight="0.25"
android:layout_width="320dip">
</SurfaceView>
<LinearLayout
android:id="@+id/linearLayout1"
android:layout_height="wrap_content"
android:layout_width="fill_parent">
<Button
android:text="播放"
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</Button>
<Button
android:text="暂停"
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</Button>
<Button
android:text="停止"
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</Button>
</LinearLayout>
</LinearLayout>
主程序：
public class SurfaceActivity extends Activity implements SurfaceHolder.Callback {
/** Called when the activity is first created. */
MediaPlayer player;
SurfaceView surface;
SurfaceHolder surfaceHolder;
Button play,pause,stop;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
play=(Button)findViewById(R.id.button1);
pause=(Button)findViewById(R.id.button2);
stop=(Button)findViewById(R.id.button3);
surface=(SurfaceView)findViewById(R.id.surface);
surfaceHolder=surface.getHolder();//SurfaceHolder是SurfaceView的控制接口
surfaceHolder.addCallback(this); //因为这个类实现了SurfaceHolder.Callback接口，所以回调参数直接this
surfaceHolder.setFixedSize(320, 220);//显示的分辨率,不设置为视频默认
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//Surface类型
play.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
player.start();
}});
pause.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
player.pause();
}});
stop.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
player.stop();
}});
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
}
@Override
public void surfaceCreated(SurfaceHolder arg0) {
//必须在surface创建后才能初始化MediaPlayer,否则不会显示图像
player=new MediaPlayer();
player.setAudioStreamType(AudioManager.STREAM_MUSIC);
player.setDisplay(surfaceHolder);
//设置显示视频显示在SurfaceView上
try {
player.setDataSource("/sdcard/3.mp4");
player.prepare();
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
}
@Override protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
if(player.isPlaying()){
player.stop(); }
player.release();
//Activity销毁时停止播放，释放资源。不做这个操作，即使退出还是能听到视频播放的声音
}
}
2.案例二
布局文件main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#ffffff"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/filename"
/>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="oppo.mp4"
android:id="@+id/filename"
/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:src="@drawable/play"
android:id="@+id/play"
/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:src="@drawable/pause"
android:id="@+id/pause"
/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:src="@drawable/stop"
android:id="@+id/stop"
/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:src="@drawable/reset"
android:id="@+id/reset"
/>
</LinearLayout>
<SurfaceView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/surfaceview"
/>
</LinearLayout>
主程序VodeoPlayActivity.java
public class VodeoPlayActivity extends Activity {
/** Called when the activity is first created. */
private EditText filenamEditText;
private MediaPlayer mediaPlayer;
private String filename;
private SurfaceView surfaceView;
private final static String TAG="VodeoPlayActivity";
private int prosition=0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
filenamEditText=(EditText) this.findViewById(R.id.filename);
surfaceView=(SurfaceView)this.findViewById(R.id.surfaceview);
surfaceView.getHolder().setFixedSize(176, 144);//设置分辨率
surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//设置surfaceview不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前
surfaceView.getHolder().addCallback(new SurceCallBack());//对surface对象的状态进行监听
mediaPlayer=new MediaPlayer();
ButtonOnClikListiner buttonOnClikListinero=new ButtonOnClikListiner();
ImageButton start=(ImageButton) this.findViewById(R.id.play);
ImageButton pause=(ImageButton) this.findViewById(R.id.pause);
ImageButton stop=(ImageButton) this.findViewById(R.id.stop);
ImageButton replay=(ImageButton) this.findViewById(R.id.reset);
start.setOnClickListener(buttonOnClikListinero);
pause.setOnClickListener(buttonOnClikListinero);
stop.setOnClickListener(buttonOnClikListinero);
replay.setOnClickListener(buttonOnClikListinero);
}
private final class ButtonOnClikListiner implements View.OnClickListener{
@Override
public void onClick(View v) {
if(Environment.getExternalStorageState()==Environment.MEDIA_UNMOUNTED){
Toast.makeText(VodeoPlayActivity.this, "sd卡不存在", Toast.LENGTH_SHORT).show();
return;
}
filename=filenamEditText.getText().toString();
switch (v.getId()) {
case R.id.play:
play();
break;
case R.id.pause:
if(mediaPlayer.isPlaying()){
mediaPlayer.pause();
}else{
mediaPlayer.start();
}
break;
case R.id.reset:
if(mediaPlayer.isPlaying()){
mediaPlayer.seekTo(0);
}else{
play();
}
break;
case R.id.stop:
if(mediaPlayer.isPlaying()){
mediaPlayer.stop();
}
break;
}
}
}
private void play() {
try {
File file=new File(Environment.getExternalStorageDirectory(),filename);
mediaPlayer.reset();//重置为初始状态
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);//设置音乐流的类型
mediaPlayer.setDisplay(surfaceView.getHolder());//设置video影片以surfaceviewholder播放
mediaPlayer.setDataSource(file.getAbsolutePath());//设置路径
mediaPlayer.prepare();//缓冲
mediaPlayer.start();//播放
} catch (Exception e) {
Log.e(TAG, e.toString());
e.printStackTrace();
}
}
private final class SurceCallBack implements SurfaceHolder.Callback{
/** * 画面修改 */
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// TODO Auto-generated method stub
}
/** * 画面创建 */
@Override
public void surfaceCreated(SurfaceHolder holder) {
if(prosition>0&&filename!=null){
play();
mediaPlayer.seekTo(prosition);
prosition=0; }
}
/** * 画面销毁 */
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
if(mediaPlayer.isPlaying()){
prosition=mediaPlayer.getCurrentPosition();
mediaPlayer.stop();
}
}
}
}
