从 /samples/android-16 >/ApiDemos 上传了一个示例。一个项目中有几个例子。从那里提取一个-MediaPlayerDemo_Video，像这样：
Mediaplayer_video.java
package com.example.mediaplayer_video;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnBufferingUpdateListener;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnPreparedListener;
import android.media.MediaPlayer.OnVideoSizeChangedListener;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.Toast;
public class Mediaplayer_video extends Activity implements
OnBufferingUpdateListener, OnCompletionListener,
OnPreparedListener, OnVideoSizeChangedListener, SurfaceHolder.Callback {
private static final String TAG = "MediaPlayerVideo";
private int mVideoWidth;
private int mVideoHeight;
private MediaPlayer mMediaPlayer;
private SurfaceView mPreview;
private SurfaceHolder holder;
private String path;
private Bundle extras;
private static final String MEDIA = "media";
private boolean mIsVideoSizeKnown = false;
private boolean mIsVideoReadyToBePlayed = false;
/**
*
* Called when the activity is first created.
*/
@SuppressWarnings("deprecation")
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.mediaplayer_2);
mPreview = (SurfaceView) findViewById(R.id.surface);
holder = mPreview.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
extras = getIntent().getExtras();
}
private void playVideo(Integer Media) {
doCleanUp();
try {
path = "sdcard/scheen.mp4";
if (path == "") {
// Tell the user to provide a media file URL.
Toast
.makeText(
Mediaplayer_video.this,
"Please edit Mediaplayer_Video Activity, "
+ "and set the path variable to your media file path."
+ " Your media file must be stored on sdcard.",
Toast.LENGTH_LONG).show();
}
// Create a new media player and set the listeners
mMediaPlayer = new MediaPlayer();
mMediaPlayer.setDataSource(path);
mMediaPlayer.setDisplay(holder);
mMediaPlayer.prepare();
mMediaPlayer.setOnBufferingUpdateListener(this);
mMediaPlayer.setOnCompletionListener(this);
mMediaPlayer.setOnPreparedListener(this);
mMediaPlayer.setOnVideoSizeChangedListener(this);
mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
} catch (Exception e) {
Log.e(TAG, "error: " + e.getMessage(), e);
}
}
public void onBufferingUpdate(MediaPlayer arg0, int percent) {
Log.d(TAG, "onBufferingUpdate percent:" + percent);
}
public void onCompletion(MediaPlayer arg0) {
Log.d(TAG, "onCompletion called");
}
public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
Log.v(TAG, "onVideoSizeChanged called");
if (width == 0 || height == 0) {
Log.e(TAG, "invalid video width(" + width + ") or height(" + height + ")");
return;
}
mIsVideoSizeKnown = true;
mVideoWidth = width;
mVideoHeight = height;
if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown) {
startVideoPlayback();
}
}
public void onPrepared(MediaPlayer mediaplayer) {
Log.d(TAG, "onPrepared called");
mIsVideoReadyToBePlayed = true;
if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown) {
startVideoPlayback();
}
}
public void surfaceChanged(SurfaceHolder surfaceholder, int i, int j, int k) {
Log.d(TAG, "surfaceChanged called");
}
public void surfaceDestroyed(SurfaceHolder surfaceholder) {
Log.d(TAG, "surfaceDestroyed called");
}
public void surfaceCreated(SurfaceHolder holder) {
Log.d(TAG, "surfaceCreated called");
playVideo(extras.getInt(MEDIA));
}
@Override
protected void onPause() {
super.onPause();
releaseMediaPlayer();
doCleanUp();
}
@Override
protected void onDestroy() {
super.onDestroy();
releaseMediaPlayer();
doCleanUp();
}
private void releaseMediaPlayer() {
if (mMediaPlayer != null) {
mMediaPlayer.release();
mMediaPlayer = null;
}
}
private void doCleanUp() {
mVideoWidth = 0;
mVideoHeight = 0;
mIsVideoReadyToBePlayed = false;
mIsVideoSizeKnown = false;
}
private void startVideoPlayback() {
Log.v(TAG, "startVideoPlayback");
holder.setFixedSize(mVideoWidth, mVideoHeight);
mMediaPlayer.start();
}
}
mediaplayer_2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".Mediaplayer_video" >
<SurfaceView
android:id="@+id/surface"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" >
</SurfaceView>
</LinearLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mediaplayer_video"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="16" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.mediaplayer_video.Mediaplayer_video"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
带有此徽标的瀑布：
07-20 17:54:04.597: E/Trace(5713): error opening trace file: No such file or directory (2)
07-20 17:54:07.006: D/MediaPlayerVideo(5713): surfaceCreated called
07-20 17:54:07.106: D/AndroidRuntime(5713): Shutting down VM
07-20 17:54:07.106: W/dalvikvm(5713): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
07-20 17:54:07.236: E/AndroidRuntime(5713): FATAL EXCEPTION: main
07-20 17:54:07.236: E/AndroidRuntime(5713): java.lang.NullPointerException
07-20 17:54:07.236: E/AndroidRuntime(5713): at com.example.mediaplayer_video.Mediaplayer_video.surfaceCreated(Mediaplayer_video.java:128)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.SurfaceView.updateWindow(SurfaceView.java:543)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.SurfaceView.access$000(SurfaceView.java:81)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:169)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:671)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1820)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4214)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.Choreographer.doCallbacks(Choreographer.java:555)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.Choreographer.doFrame(Choreographer.java:525)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.os.Handler.handleCallback(Handler.java:615)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.os.Handler.dispatchMessage(Handler.java:92)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.os.Looper.loop(Looper.java:137)
07-20 17:54:07.236: E/AndroidRuntime(5713): at android.app.ActivityThread.main(ActivityThread.java:4745)
07-20 17:54:07.236: E/AndroidRuntime(5713): at java.lang.reflect.Method.invokeNative(Native Method)
07-20 17:54:07.236: E/AndroidRuntime(5713): at java.lang.reflect.Method.invoke(Method.java:511)
07-20 17:54:07.236: E/AndroidRuntime(5713): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
07-20 17:54:07.236: E/AndroidRuntime(5713): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
07-20 17:54:07.236: E/AndroidRuntime(5713): at dalvik.system.NativeStart.main(Native Method)
有想法，怎么了？