播放视频

使用MediaPlayer可以播放音频，也可以播放视频，

播放视频时考虑到图片刷新频率高，可以使用SerfaceView组件完成。

本程序只能播放.3gp格式的视频，要想播放其他格式的视频需要使用其他算法。

在sdcard里面存放一个名为Vieo.3gp的视频文件。

在main.xml中：

<LinearLayout

    xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:background="#000000"

    android:gravity="center_horizontal"

    android:orientation="vertical">

    <LinearLayout

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginTop="20dp"

        android:gravity="center_horizontal">

        <ImageButton

            android:id="@+id/play"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:src="@drawable/play"/>

        <ImageButton

            android:id="@+id/stop"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:src="@drawable/stop"/>

    </LinearLayout>

    <SurfaceView

        android:id="@+id/surfaceView"

        android:layout_margin="50dp"

        android:layout_width="fill_parent"

        android:layout_height="180dp"/>

</LinearLayout>

在MyVideoDemo.java中：

package com.li.video;

import java.io.IOException;

import android.media.AudioManager;

import android.media.MediaPlayer;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.MenuItem;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.ImageButton;

import android.support.v4.app.NavUtils;

public class MyVideoDemo extends Activity {

  private ImageButton play = null;

  private ImageButton stop = null;

  private MediaPlayer media = null;

  private SurfaceView surfaceView = null;

  private SurfaceHolder surfaceHolder = null;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        super.setContentView(R.layout.main);

        this.play = (ImageButton)super.findViewById(R.id.play);

        this.stop = (ImageButton)super.findViewById(R.id.stop);

        this.surfaceView = (SurfaceView)super.findViewById(R.id.surfaceView);

        this.surfaceHolder = this.surfaceView.getHolder();

        this.surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        this.media = new MediaPlayer();

        try {

       this.media.setDataSource("/sdcard/wmv.3gp");

     } catch (IllegalArgumentException e) {

       e.printStackTrace();

     } catch (IllegalStateException e) {

       e.printStackTrace();

     } catch (IOException e) {

       e.printStackTrace();

     }

        this.play.setOnClickListener(new PlayOnClickListener());

        this.stop.setOnClickListener(new StopOnClickListener());

       

    }

    private class PlayOnClickListener implements OnClickListener{

     public void onClick(View v) {

       MyVideoDemo.this.media.setAudioStreamType(AudioManager.STREAM_MUSIC);

       MyVideoDemo.this.media.setDisplay(MyVideoDemo.this.surfaceHolder);

       try {

         MyVideoDemo.this.media.prepare();

       } catch (IllegalStateException e) {

         e.printStackTrace();

       } catch (IOException e) {

         e.printStackTrace();

       }

       MyVideoDemo.this.media.start();

     }

    }

    private class StopOnClickListener implements OnClickListener{

    public void onClick(View v) {

        MyVideoDemo.this.media.stop();

    }

    }

}