以下媒体播放器可以正常工作，但每次暂停活动时（例如屏幕关闭或来电），媒体播放器都会从位置0开始，但不会处于暂停位置。
有没有人提示，当活动恢复时，如何设置最后一个位置以让玩家在最后一个位置恢复？
MediaPlayer活动：
public class PoiView extends ActionBarActivity implements MediaPlayer.OnCompletionListener {
MediaPlayer mediaPlayer;
private double startTime = 0;
private double finalTime = 0;
private Handler myHandler = new Handler();
private SeekBar seekbar;
private ImageButton playButton,pauseButton;
public static int oneTimeOnly = 0;
public TextView startTimeField,endTimeField;
boolean isPrepared = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_poi_view);
getActionBar().setDisplayHomeAsUpEnabled(true);
seekbar = (SeekBar)findViewById(R.id.seekBar);
playButton = (ImageButton)findViewById(R.id.imagePlay);
pauseButton = (ImageButton)findViewById(R.id.imagePause);
startTimeField =(TextView)findViewById(R.id.textStart);
seekbar.setClickable(false);
pauseButton.setEnabled(false);
endTimeField =(TextView)findViewById(R.id.textStop);
try {
//mediaPlayer.prepare();
int resID=getResources().getIdentifier(poiAudio, "raw", getPackageName());
mediaPlayer = MediaPlayer.create(this, resID);
isPrepared = true;
mediaPlayer.setOnCompletionListener(this);
} catch (NullPointerException e) {
Context context = getApplicationContext();
CharSequence text = getResources().getString(R.string.audioerror);
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(context, text, duration);
toast.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, 0);
toast.show();
}
}
public void play(View view) {
Toast.makeText(getApplicationContext(), R.string.audio_play,
Toast.LENGTH_SHORT).show();
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
mediaPlayer.start();
finalTime = mediaPlayer.getDuration();
startTime = mediaPlayer.getCurrentPosition();
if (oneTimeOnly == 0) {
seekbar.setMax((int) finalTime);
oneTimeOnly = 1;
}
endTimeField.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) finalTime),
TimeUnit.MILLISECONDS.toSeconds((long) finalTime) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
toMinutes((long) finalTime)))
);
startTimeField.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) startTime),
TimeUnit.MILLISECONDS.toSeconds((long) startTime) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
toMinutes((long) startTime)))
);
seekbar.setProgress((int)startTime);
myHandler.postDelayed(UpdateSongTime,100);
pauseButton.setEnabled(true);
playButton.setEnabled(false);
}
private Runnable UpdateSongTime = new Runnable() {
public void run() {
startTime = mediaPlayer.getCurrentPosition();
startTimeField.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) startTime),
TimeUnit.MILLISECONDS.toSeconds((long) startTime) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
toMinutes((long) startTime)))
);
seekbar.setProgress((int)startTime);
myHandler.postDelayed(this, 100);
}
};
public void pause(View view){
Toast.makeText(getApplicationContext(), R.string.audio_pause,
Toast.LENGTH_SHORT).show();
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
mediaPlayer.pause();
pauseButton.setEnabled(false);
playButton.setEnabled(true);
startTime = mediaPlayer.getCurrentPosition();
}
@Override
public void onSaveInstanceState (Bundle outState) {
super.onSaveInstanceState(outState);
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// Restore UI state from the savedInstanceState.
// This bundle has also been passed to onCreate.
}
@Override
public void onPause() {
super.onPause();
myHandler.removeCallbacksAndMessages(null);
Bundle b = new Bundle();
if (mediaPlayer != null) {
b.putDouble("starttime", startTime);
//mediaPlayer.release();
pauseButton.setEnabled(false);
playButton.setEnabled(true);
}
}
@Override
public void onResume() {
super.onResume();
Bundle b = getIntent().getExtras();
if (mediaPlayer == null) {
int resID=getResources().getIdentifier(poiAudio, "raw", getPackageName());
mediaPlayer = MediaPlayer.create(this, resID);
} else {
//mediaPlayer.pause();
startTime = mediaPlayer.getCurrentPosition();
seekbar.setProgress((int) startTime);
mediaPlayer.seekTo((int) startTime);
}
}
@Override
public void onRestart() {
super.onRestart();
Bundle b = getIntent().getExtras();
if (mediaPlayer == null) {
int resID=getResources().getIdentifier(poiAudio, "raw", getPackageName());
mediaPlayer = MediaPlayer.create(this, resID);
startTime = mediaPlayer.getCurrentPosition();
}
}
@Override
public void onCompletion(MediaPlayer mediaPlayer) {
mediaPlayer.stop();
mediaPlayer.release();
pauseButton.setEnabled(false);
playButton.setEnabled(true);
startTime = 0;
seekbar.setProgress((int) startTime);
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
public class MusicIntentReceiver extends android.content.BroadcastReceiver {
@Override
public void onReceive(Context ctx, Intent intent) {
if (intent.getAction().equals(
android.media.AudioManager.ACTION_AUDIO_BECOMING_NOISY)) {
mediaPlayer.pause();
pauseButton.setEnabled(false);
playButton.setEnabled(true);
startTime = mediaPlayer.getCurrentPosition();
seekbar.setProgress((int)startTime);
Bundle b = new Bundle();
b.putDouble("starttime", startTime);
}
}
}
@Override
public void onStop() {
super.onStop();
if (mediaPlayer != null) {
mediaPlayer.release();
mediaPlayer = null;
}
myHandler.removeCallbacksAndMessages(null);
Bundle b = new Bundle();
b.putDouble("starttime", startTime);
}
private void unbindDrawables(View view)
{
if (view.getBackground() != null)
{
view.getBackground().setCallback(null);
}
if (view instanceof ViewGroup && !(view instanceof AdapterView))
{
for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++)
{
unbindDrawables(((ViewGroup) view).getChildAt(i));
}
((ViewGroup) view).removeAllViews();
}
}
@Override
public void onDestroy() {
super.onDestroy();
unbindDrawables(findViewById(R.id.imagePoi));
System.gc();
Bundle b = new Bundle();
b.putDouble("starttime", startTime);
if (mediaPlayer != null) mediaPlayer.release();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.poi_view, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.home:
NavUtils.navigateUpFromSameTask(this);
Intent backrouteview = NavUtils.getParentActivityIntent(this);
backrouteview.putExtra("route", routeSave);
backrouteview.putExtra("titel_route", routeTitel);
startActivity(backrouteview);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
答案 0 :(得分：0)
以下是修改后的主要活动文件src / com.example.mediaplayer / MainActivity.java的内容。
package com.example.mediaplayer;
import java.util.concurrent.TimeUnit;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
public TextView songName,startTimeField,endTimeField;
private MediaPlayer mediaPlayer;
private double startTime = 0;
private double finalTime = 0;
private Handler myHandler = new Handler();;
private int forwardTime = 5000;
private int backwardTime = 5000;
private SeekBar seekbar;
private ImageButton playButton,pauseButton;
public static int oneTimeOnly = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
songName = (TextView)findViewById(R.id.textView4);
startTimeField =(TextView)findViewById(R.id.textView1);
endTimeField =(TextView)findViewById(R.id.textView2);
seekbar = (SeekBar)findViewById(R.id.seekBar1);
playButton = (ImageButton)findViewById(R.id.imageButton1);
pauseButton = (ImageButton)findViewById(R.id.imageButton2);
songName.setText("song.mp3");
mediaPlayer = MediaPlayer.create(this, R.raw.song);
seekbar.setClickable(false);
pauseButton.setEnabled(false);
}
public void play(View view){
Toast.makeText(getApplicationContext(), "Playing sound",
Toast.LENGTH_SHORT).show();
mediaPlayer.start();
finalTime = mediaPlayer.getDuration();
startTime = mediaPlayer.getCurrentPosition();
if(oneTimeOnly == 0){
seekbar.setMax((int) finalTime);
oneTimeOnly = 1;
}
endTimeField.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) finalTime),
TimeUnit.MILLISECONDS.toSeconds((long) finalTime) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
toMinutes((long) finalTime)))
);
startTimeField.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) startTime),
TimeUnit.MILLISECONDS.toSeconds((long) startTime) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
toMinutes((long) startTime)))
);
seekbar.setProgress((int)startTime);
myHandler.postDelayed(UpdateSongTime,100);
pauseButton.setEnabled(true);
playButton.setEnabled(false);
}
private Runnable UpdateSongTime = new Runnable() {
public void run() {
startTime = mediaPlayer.getCurrentPosition();
startTimeField.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) startTime),
TimeUnit.MILLISECONDS.toSeconds((long) startTime) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.
toMinutes((long) startTime)))
);
seekbar.setProgress((int)startTime);
myHandler.postDelayed(this, 100);
}
};
public void pause(View view){
Toast.makeText(getApplicationContext(), "Pausing sound",
Toast.LENGTH_SHORT).show();
mediaPlayer.pause();
pauseButton.setEnabled(false);
playButton.setEnabled(true);
}
public void forward(View view){
int temp = (int)startTime;
if((temp+forwardTime)<=finalTime){
startTime = startTime + forwardTime;
mediaPlayer.seekTo((int) startTime);
}
else{
Toast.makeText(getApplicationContext(),
"Cannot jump forward 5 seconds",
Toast.LENGTH_SHORT).show();
}
}
public void rewind(View view){
int temp = (int)startTime;
if((temp-backwardTime)>0){
startTime = startTime - backwardTime;
mediaPlayer.seekTo((int) startTime);
}
else{
Toast.makeText(getApplicationContext(),
"Cannot jump backward 5 seconds",
Toast.LENGTH_SHORT).show();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
以下是xml res / layout / activity_main.xml的修改内容。
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<ImageButton
android:id="@+id/imageButton3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_marginBottom="14dp"
android:onClick="forward"
android:src="@android:drawable/ic_media_ff" />
<ImageButton
android:id="@+id/imageButton4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignTop="@+id/imageButton2"
android:layout_marginLeft="22dp"
android:layout_toRightOf="@+id/imageButton2"
android:onClick="rewind"
android:src="@android:drawable/ic_media_rew" />
<ImageButton
android:id="@+id/imageButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/imageButton1"
android:layout_marginLeft="14dp"
android:layout_toRightOf="@+id/imageButton1"
android:onClick="pause"
android:src="@android:drawable/ic_media_pause" />
<ImageButton
android:id="@+id/imageButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/imageButton3"
android:layout_marginLeft="24dp"
android:layout_toRightOf="@+id/imageButton3"
android:onClick="play"
android:src="@android:drawable/ic_media_play" />
<SeekBar
android:id="@+id/seekBar1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/imageButton3"
android:layout_toLeftOf="@+id/textView2"
android:layout_toRightOf="@+id/textView1" />
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/imageButton3"
android:layout_alignTop="@+id/seekBar1"
android:text="@string/inital_Time"
android:textAppearance="?android:attr/textAppearanceSmall" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/imageButton4"
android:layout_alignTop="@+id/seekBar1"
android:text="@string/inital_Time"
android:textAppearance="?android:attr/textAppearanceSmall" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/imageButton3"
android:text="@string/hello_world"
android:textAppearance="?android:attr/textAppearanceMedium" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_below="@+id/textView3"
android:src="@drawable/ic_launcher" />
<TextView
android:id="@+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/textView3"
android:layout_alignBottom="@+id/textView3"
android:layout_toRightOf="@+id/imageButton1"
android:text="TextView" />
</RelativeLayout>
以下是res / values / string.xml的内容。
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">MediaPlayer</string>
<string name="action_settings">Settings</string>
<string name="hello_world">Now Playing:</string>
<string name="inital_Time">0 min, 0 sec</string>
</resources>
以下是AndroidManifest.xml文件的内容。
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mediaplayer"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.mediaplayer.MainActivity"
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>