Android：使用网页在mediaplayer中显示当前曲目信息
我是一名学习者，正在开发一款Android应用程序来播放实时流。除1个问题外，它工作正常。我想显示当前正在播放的曲目的标题，该曲目在webpge上可用。为此，我使用了textView并尝试使用异步任务，并调用了一个方法，该方法在该异步任务中包含Runnable，我可以使用该方法每隔30秒更新textView的文本。在Runnable中，我调用了一个方法，该方法加载网页并将其内容作为字符串提供 问题：当它试图更新textView的文本时，应用程序崩溃。提前谢谢 以下是我的代码： 我明白了 我使用了一个TimeTask，它调用一个UpdateGUI方法；每隔10秒。此方法更新了用户界面；进一步调用getHTML方法；将网页内容加载到字符串文本。此外，此方法还通过位于的myHandler调用myRunnable myHandler.postmyrunable 和myRunnable设置textView txtMessage的文本 要完全理解该过程，请阅读 代码现在是：Android：使用网页在mediaplayer中显示当前曲目信息,android,android-asynctask,inputstream,android-mediaplayer,runnable,Android,Android Asynctask,Inputstream,Android Mediaplayer,Runnable,我是一名学习者，正在开发一款Android应用程序来播放实时流。除1个问题外，它工作正常。我想显示当前正在播放的曲目的标题，该曲目在webpge上可用。为此，我使用了textView并尝试使用异步任务，并调用了一个方法，该方法在该异步任务中包含Runnable，我可以使用该方法每隔30秒更新textView的文本。在Runnable中，我调用了一个方法，该方法加载网页并将其内容作为字符串提供 问题：当它试图更新textView的文本时，应用程序崩溃。提前谢谢 以下是我的代码： 我明白了 我使用了
import java.io.IOException;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Handler;
import java.net.URLConnection;
import java.net.URL;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import android.util.Log;
import java.net.MalformedURLException;
import android.widget.TextView;
import java.util.TimerTask;
import java.util.Timer;
public class MusicAndroidActivity extends Activity {
static MediaPlayer mPlayer;
Button buttonPlay;
Button buttonStop;
Button buttonPause;
public TextView txtMessage;
private StringBuilder response;
private String text="***";
ProgressDialog progDailog;
final Handler myHandler = new Handler();
int length=0;
String url = "http://www.example.com:port/;stream.mp3";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
buttonStop = (Button) findViewById(R.id.stop);
txtMessage=(TextView)findViewById(R.id.txtMessage);
buttonStop.setEnabled(false);
buttonPause=(Button) findViewById(R.id.pause);
buttonPause.setEnabled(false);
buttonPlay = (Button) findViewById(R.id.play);
buttonPlay.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPlayer = new MediaPlayer();
mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
buttonPlay.setEnabled(false);
buttonStop.setEnabled(true);
buttonPause.setEnabled(true);
progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true);
mPlayer.setDataSource(url);
} catch (IllegalArgumentException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (SecurityException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
}
try {
mPlayer.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mPlayer) {
// TODO Auto-generated method stub
mPlayer.start();
progDailog.dismiss();
}
});
mPlayer.prepareAsync();
Timer myTimer = new Timer(); // Declared Timer
myTimer.schedule(new TimerTask() { // Started Time Task, it will repeat as per given duration (Ours is 1000 or 10 Second)
@Override
public void run() {
UpdateGUI(); // Called Method UdateGUI
} // v
}, 0, 10000); // After Every 10 Seconds
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
}
}
});
buttonStop.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.stop();
buttonPlay.setEnabled(true);
buttonStop.setEnabled(false);
buttonPause.setEnabled(false);
}
}
});
buttonPause.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.pause();
length=mPlayer.getCurrentPosition();
buttonPause.setText("Play");
buttonStop.setEnabled(true);
buttonPlay.setEnabled(false);
}
else {
mPlayer.start();
buttonPause.setText("Pause");
}
}
});
}
protected void onDestroy() {
super.onDestroy();
// TODO Auto-generated method stub
if (mPlayer != null) {
mPlayer.release();
mPlayer = null;
}
}
private void UpdateGUI() {
getHTML();
myHandler.post(myRunnable); // Posted MyRunnable to myHandler
}
final Runnable myRunnable = new Runnable() {
public void run() {
txtMessage.setText(text); //Set txtMessage's value to text (text is a string declared above)
}
};
private void getHTML()
{
try {
URLConnection connection = new URL("http://example.com/stats/index.php").openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
line = br.readLine();
{
response.append(line);
}
text = response.toString();
} catch (MalformedURLException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
} catch (IOException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
}
}
}
你的航海日志在哪里？？？对不起，我错过了。现在我添加了有问题的logcat，请检查。您的MusicAndroidActivity$LoadWebPageASYNC在哪里？它在代码中，请检查。
java.lang.SecurityException: Permission denial: writing to settings requires android.permission.WRITE_SETTINGS
at com.android.providers.settings.SettingsProvider.callFromPackage(SettingsProvider.java:645)
at android.content.ContentProvider$Transport.call(ContentProvider.java:279)
at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:273)
at android.os.Binder.execTransact(Binder.java:388)
at dalvik.system.NativeStart.run(Native Method)
05-29 10:56:45.772 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:45.772 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:48.462 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:48.462 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.702 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.702 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.712 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.712 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:57:01.772 28164-28569/com.prgguru.example E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
at java.util.concurrent.FutureTask.run(FutureTask.java:239)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:5969)
at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:921)
at android.view.ViewGroup.invalidateChild(ViewGroup.java:4276)
at android.view.View.invalidate(View.java:10552)
at android.view.View.invalidate(View.java:10507)
at android.widget.TextView.checkForRelayout(TextView.java:6531)
at android.widget.TextView.setText(TextView.java:3789)
at android.widget.TextView.setText(TextView.java:3643)
at android.widget.TextView.setText(TextView.java:3618)
at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:158)
at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:152)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
import java.io.IOException;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Handler;
import java.net.URLConnection;
import java.net.URL;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import android.util.Log;
import java.net.MalformedURLException;
import android.widget.TextView;
import java.util.TimerTask;
import java.util.Timer;
public class MusicAndroidActivity extends Activity {
static MediaPlayer mPlayer;
Button buttonPlay;
Button buttonStop;
Button buttonPause;
public TextView txtMessage;
private StringBuilder response;
private String text="***";
ProgressDialog progDailog;
final Handler myHandler = new Handler();
int length=0;
String url = "http://www.example.com:port/;stream.mp3";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
buttonStop = (Button) findViewById(R.id.stop);
txtMessage=(TextView)findViewById(R.id.txtMessage);
buttonStop.setEnabled(false);
buttonPause=(Button) findViewById(R.id.pause);
buttonPause.setEnabled(false);
buttonPlay = (Button) findViewById(R.id.play);
buttonPlay.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPlayer = new MediaPlayer();
mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
buttonPlay.setEnabled(false);
buttonStop.setEnabled(true);
buttonPause.setEnabled(true);
progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true);
mPlayer.setDataSource(url);
} catch (IllegalArgumentException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (SecurityException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
}
try {
mPlayer.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mPlayer) {
// TODO Auto-generated method stub
mPlayer.start();
progDailog.dismiss();
}
});
mPlayer.prepareAsync();
Timer myTimer = new Timer(); // Declared Timer
myTimer.schedule(new TimerTask() { // Started Time Task, it will repeat as per given duration (Ours is 1000 or 10 Second)
@Override
public void run() {
UpdateGUI(); // Called Method UdateGUI
} // v
}, 0, 10000); // After Every 10 Seconds
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
}
}
});
buttonStop.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.stop();
buttonPlay.setEnabled(true);
buttonStop.setEnabled(false);
buttonPause.setEnabled(false);
}
}
});
buttonPause.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.pause();
length=mPlayer.getCurrentPosition();
buttonPause.setText("Play");
buttonStop.setEnabled(true);
buttonPlay.setEnabled(false);
}
else {
mPlayer.start();
buttonPause.setText("Pause");
}
}
});
}
protected void onDestroy() {
super.onDestroy();
// TODO Auto-generated method stub
if (mPlayer != null) {
mPlayer.release();
mPlayer = null;
}
}
private void UpdateGUI() {
getHTML();
myHandler.post(myRunnable); // Posted MyRunnable to myHandler
}
final Runnable myRunnable = new Runnable() {
public void run() {
txtMessage.setText(text); //Set txtMessage's value to text (text is a string declared above)
}
};
private void getHTML()
{
try {
URLConnection connection = new URL("http://example.com/stats/index.php").openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
line = br.readLine();
{
response.append(line);
}
text = response.toString();
} catch (MalformedURLException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
} catch (IOException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
}
}
}