在我的媒体播放器（mp3）中有一个搜索栏。为了播放下一首歌我正在使用这个逻辑：
if（seek bar progress == mediaplayerObject.getDuration（））
如果是的话 播放下一首歌
但是这个条件不起作用，因为在完整的搜索栏进度和mediaplayerObject.getDuration（）值之间存在一个小的mili第二个差距，这个差异不是静态的。我认为这是因为处理时间的延迟。如果我可以使用像if seek bar progress is 100%这样的条件我可以使用它，但我尝试过它似乎不起作用
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.SeekBar;
import android.widget.TextView;
public class AndroidMediaPlayerExample extends Activity {
private MediaPlayer mediaPlayer;
public TextView songName, duration;
private double timeElapsed = 0, finalTime = 0;
private int forwardTime = 2000, backwardTime = 2000;
private Handler durationHandler = new Handler();
private SeekBar seekbar;
private Field[] fields;
private String name;
private int resourceID;
private List<String> songNames;
private int nameIntRandom;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//set the layout of the Activity
setContentView(R.layout.activity_main);
songNames = new ArrayList();
//initialize views
initializeViews();
seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
// seekBar.setMax(mediaPlayer.getDuration());
System.out.println("progress"+ (progress));
System.out.println("progress final - "+ finalTime);
if(progress == finalTime){
System.out.println("progress 100 compleated ");
}
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
public void initializeViews(){
listRaw();
songName = (TextView) findViewById(R.id.songName);
nameIntRandom = Integer.parseInt(songNames.get(2));
mediaPlayer = MediaPlayer.create(this, nameIntRandom);
finalTime = mediaPlayer.getDuration();
duration = (TextView) findViewById(R.id.songDuration);
seekbar = (SeekBar) findViewById(R.id.seekBar);
songName.setText("Sample_Song.mp3");
seekbar.setMax((int) finalTime);
seekbar.setClickable(false);
}
// play mp3 song
public void play(View view) {
System.out.println("AndroidMediaPlayerExample play");
mediaPlayer.start();
timeElapsed = mediaPlayer.getCurrentPosition();
seekbar.setProgress((int) timeElapsed);
durationHandler.postDelayed(updateSeekBarTime, 100);
}
//handler to change seekBarTime
private Runnable updateSeekBarTime = new Runnable() {
public void run() {
//get current position
timeElapsed = mediaPlayer.getCurrentPosition();
//set seekbar progress
seekbar.setProgress((int) timeElapsed);
//set time remaing
double timeRemaining = finalTime - timeElapsed;
duration.setText(String.format("%d min, %d sec", TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining), TimeUnit.MILLISECONDS.toSeconds((long) timeRemaining) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining))));
//repeat yourself that again in 100 miliseconds
durationHandler.postDelayed(this, 100);
}
};
// pause mp3 song
public void pause(View view) {
mediaPlayer.pause();
}
// go forward at forwardTime seconds
public void forward(View view) {
//check if we can go forward at forwardTime seconds before song endes
if ((timeElapsed + forwardTime) <= finalTime) {
timeElapsed = timeElapsed + forwardTime;
//seek to the exact second of the track
mediaPlayer.seekTo((int) timeElapsed);
}
}
public void listRaw() {
fields = R.raw.class.getFields();
for (int count = 0; count < fields.length; count++) {
Log.i("Raw Asset: ", fields[count].getName());
System.out.println("length .... " + fields[count].getName());
try {
System.out.println("trytrytrytry");
resourceID = fields[count].getInt(fields[count]);
System.out.println("resourceIDresourceID " + resourceID);
name = String.valueOf(resourceID);
songNames.add(name);
System.out.println("songNames.size();" +songNames.size());
songNames.size();
} catch (IllegalAccessException e) {
e.printStackTrace();
System.out.println("catch" + e);
}
}
System.out.println("resourceIDresourceID---------lastone " + resourceID);
System.out.println("resourceIDresourceID---------set " + fields.toString());
}
// go backwards at backwardTime seconds
public void rewind(View view) {
//check if we can go back at backwardTime seconds after song starts
if ((timeElapsed - backwardTime) > 0) {
timeElapsed = timeElapsed - backwardTime;
//seek to the exact second of the track
mediaPlayer.seekTo((int) timeElapsed);
}
}
}
目前mp3 arraylist id已被硬编码
XML here
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:background="#333333"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin" >
<TextView
android:id="@+id/songName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="songName" />
<ImageView
android:id="@+id/mp3Image"
android:layout_width="match_parent"
android:layout_height="200dp"
android:padding="30dp"
android:src="@drawable/music"
android:background="#ffffff"
android:layout_margin="30dp" />
<TextView
android:id="@+id/songDuration"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="songDuration" />
<SeekBar
android:id="@+id/seekBar"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="30dp"
android:gravity="center_horizontal"
android:orientation="horizontal" >
<ImageButton
android:id="@+id/media_rew"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="14dp"
android:onClick="rewind"
android:src="@android:drawable/ic_media_rew" />
<ImageButton
android:id="@+id/media_pause"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="14dp"
android:onClick="pause"
android:src="@android:drawable/ic_media_pause" />
<ImageButton
android:id="@+id/media_play"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="14dp"
android:onClick="play"
android:src="@android:drawable/ic_media_play" />
<ImageButton
android:id="@+id/media_ff"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="14dp"
android:onClick="forward"
android:src="@android:drawable/ic_media_ff" />
</LinearLayout>
</LinearLayout>
答案 0 :(得分：4)
找到答案，下面我计算timeElapsed，设置搜索栏进度，计算剩余时间＆amp;显示时间已经在几分钟和几秒钟内播放
我使用了这种方法
Ps：2015年完成了这项工作，没有时间审核代码，但解释了我的所作所为。
Runnable - 此接口旨在为希望在活动时执行代码的对象提供通用协议。活动仅表示线程已启动且尚未停止。
varibales -
private Runnable updateSeekBarTime = new Runnable() {
public void run() {
//get current position
timeElapsed = mediaPlayer.getCurrentPosition();
//set seekbar progress using time played
seekbar.setProgress((int) timeElapsed);
//set time remaining in minutes and seconds
timeRemaining = finalTime - timeElapsed;
duration.setText(String.format("%d min, %d sec", TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining), TimeUnit.MILLISECONDS.toSeconds((long) timeRemaining) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining))));
//holding time for 100 miliseconds
durationHandler.postDelayed(this, 100);
}
};
所以我可以查看timeRemaining == 0
是的，媒体播放器中有一种方法
mediaPlayer.isPlaying()＆lt; ---但我没有使用这个