Java 媒体播放器错误 -38,0
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mediaPlayer error -38,0
提问by Coma White
I try to do simple online radio player. Here is adress of stream http://radio-electron.ru:8000/96Here is my code.
我尝试做简单的在线广播播放器。这是流的地址http://radio-electron.ru:8000/96这是我的代码。
MyActivity.java
我的活动.java
package com.example.untitled2;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import java.io.IOException;
public class MyActivity extends Activity {
MediaPlayer mediaPlayer;
Button playButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
@Override
public void onStart() {
super.onStart();
}
@Override
public void onResume() {
super.onResume();
mediaPlayer = new MediaPlayer();
playButton = (Button)findViewById(R.id.button);
playButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(mediaPlayer.isPlaying())
mediaPlayer.stop();
else {
try {
mediaPlayer.setDataSource(getApplicationContext(), Uri.parse("http://radio-electron.ru:8000/96"));
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setOnErrorListener(new MediaPlayer.OnErrorListener() {
@Override
public boolean onError(MediaPlayer mediaPlayer, int i, int i2) {
Toast.makeText(getApplicationContext(), "ERROR " + i, Toast.LENGTH_LONG).show();
playButton.setEnabled(false);
Log.d("radio", "error " + i + " " + i2);
return false; //To change body of implemented methods use File | Settings | File Templates.
}
});
mediaPlayer.prepareAsync();
}
catch (IOException e) {
Toast.makeText(getApplicationContext(), "ERROR " + e, Toast.LENGTH_LONG).show();
Log.d("radio", "error " + e);
}
mediaPlayer.start();
}
}
});
}
}
main.xml
主文件
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="@+id/button"
android:layout_gravity="center"/>
</FrameLayout>
I have no idea, why i get -(38, 0) code and what does it mean. I using Intellij IDEA and trying this code on Android 2.3 and 4.2 emulators and get some problem.
我不知道为什么我得到 -(38, 0) 代码以及它是什么意思。我使用 Intellij IDEA 并在 Android 2.3 和 4.2 模拟器上尝试此代码并遇到一些问题。
采纳答案by allprog
-38 refers to ENOSYSerror code from errno.h(see this explanation https://stackoverflow.com/a/15206308/768935)
-38 指的是errno.h 中的ENOSYS错误代码（见这个解释https://stackoverflow.com/a/15206308/768935）
You seem to try to start the playing before the preparation is complete. Use the setOnPreparedListener()method to set a preparation listener and call the start()method only after the preparation is complete.
您似乎在准备完成之前尝试开始播放。使用该 setOnPreparedListener()方法设置准备监听器，并start()在准备完成后调用该方法。
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
public void onPrepared(MediaPlayer mp) {
mp.start();
}
});
mediaPlayer.prepareAsync();
And remove the current mediaPlayer.start()invocation from the code.
并mediaPlayer.start()从代码中删除当前调用。
回答by Michael
The error code -38 ought to correspond to INVALID_OPERATION.
错误代码 -38 应该对应于INVALID_OPERATION.
A likely cause of this is that you don't wait for prepareAsyncto finish before you call start. You should set an onPreparedListenerand start the MediaPlayeronly when onPreparedhas been called.
造成这种情况的一个可能原因是您prepareAsync在调用 之前没有等待完成start。您应该设置一个onPreparedListener并MediaPlayer在onPrepared被调用时启动。
回答by g-hos
@allprog and @Michael are right. But there is another way, if you don't want to use prepareAsync(), use prepare(). That is blocking, which is returned only when it is prepared.
@allprog 和@Michael 是对的。但是还有另一种方法，如果您不想使用prepareAsync()，请使用prepare()。那就是阻塞，只有在准备好时才返回。
回答by Unknownweirdo
I was getting my -38error by calling getDuration();on the MediaPlayer beforeit was prepared.
我-38通过getDuration();在准备之前调用MediaPlayer 来得到我的错误。
It's worth checking the MediaPlayerdoc.
值得查看MediaPlayer文档。
There is a paragraph that starts It is a programming error to invoke methods such as getCurrentPosition()...
有一段开头 It is a programming error to invoke methods such as getCurrentPosition()...
that has a list of methods which are un-ideal to call before the MediaPlayer is prepared, which in turn may result in -38.
它有一个方法列表，在准备 MediaPlayer 之前调用这些方法是不理想的，这反过来可能会导致-38.
回答by pilotmario
You better check if you are executing any operation that is related to the playing statelike getCurrentPosition()before the Mediaplayer is started.
你最好检查一下，如果你正在执行其有关的任何操作播放状态类似getCurrentPosition()的媒体播放器开始之前。
