Android开发之MediaPlayer和SurfaceView组成视频播放器

SurfaceView

• 使用双缓冲技术
• 是个重量级的组件
• 只要不可见，就不会创建，可见时，才会创建
• 只要不可见，就会销毁

SurfaceView一旦不可见，就会被销毁，一旦可见，就会被创建，销毁时停止播放，再次创建时再开始播放

 import android.app.Activity;
 import android.media.MediaPlayer;
 import android.os.Bundle;
 import android.view.SurfaceHolder;
 import android.view.SurfaceHolder.Callback;
 import android.view.SurfaceView;

 public class MainActivity extends Activity {
     private MediaPlayer player;
     static int currentPosition;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);

         SurfaceView sv = (SurfaceView) findViewById(R.id.sv);
         // 拿到surfaceview的控制器
         final SurfaceHolder sh = sv.getHolder();
         //给SurfaceHolder设置CallBack，类似于侦听，可以知道SurfaceView的状态
         sh.addCallback(new Callback() {
             // surfaceView销毁时调用
             @Override
             public void surfaceDestroyed(SurfaceHolder holder) {
                 // 每次surfaceview销毁时，同时停止播放视频
                 if (player != null) {
                     currentPosition = player.getCurrentPosition();
                     player.stop();
                     player.release();
                     player = null;
                 }
             }

             // surfaceView创建时调用
             @Override
             public void surfaceCreated(SurfaceHolder holder) {
                 // 每次surfaceView创建时才去播放视频
                 if (player == null) {
                     player = new MediaPlayer();
                     player.reset();
                     try {
                         player.setDataSource("sdcard/2.3gp");
                         player.setDisplay(sh);
                         player.prepare();
                         player.start();
                         player.seekTo(currentPosition);
                     } catch (Exception e) {
                         e.printStackTrace();
                     }
                 }

             }

             // surfaceView结构改变时调用
             @Override
             public void surfaceChanged(SurfaceHolder holder, int format,
                     int width, int height) {
             }
         });
     }
 }