Question

当我在Android模拟器中启动以下应用程序时，应用程序将停止并显示以下错误消息：“应用程序播放器（进程kilbo.net）已意外停止。请再试一次。” 没有错误，警告，我在调试器中找不到与问题相关的任何内容。这是我遇到的一个常见问题，而不仅仅是这个应用程序。

    package kilbo.net;

import java.io.IOException;

import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

public class Player extends Activity implements Runnable, OnClickListener{

   private TextView Status;
   private ProgressBar progressBar;
   private Button StartMedia;
   private Button Stop;
   private MediaPlayer mp;      

   @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

       Status = (TextView) findViewById(R.id.Status);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        StartMedia = (Button) findViewById(R.id.StartMedia);
        Stop = (Button) findViewById(R.id.Stop);

//Removing this two lines "fixes" the problem. So the error is probably related to this
        StartMedia.setOnClickListener(this);
        Stop.setOnClickListener(this);                
    }        

   @Override
    public void onClick(View v) {
        if(v.equals(StartMedia)){
            if(mp != null && mp.isPlaying()) return;
            MediaPlayer mp = new MediaPlayer();
            try {
                mp.setDataSource("http://kilbo.net/musik/Norrskenet.mp3");
            } catch (IllegalArgumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IllegalStateException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            mp.start();               
            Status.setText("playingMedia");         
            progressBar.setVisibility(ProgressBar.VISIBLE);
            progressBar.setProgress(0);
            progressBar.setMax(mp.getDuration());
            new Thread(this).start();
        }

        if(v.equals(Stop) && mp!=null){
            mp.stop();
            mp = null;            
            Status.setText("Stop");
            progressBar.setVisibility(ProgressBar.GONE);
        }

   }

    @Override
    public void run() {
        int CurrentPosition= 0;
        int total = mp.getDuration();
        while(mp!=null && CurrentPosition<total){
            try {
                Thread.sleep(1000);
                CurrentPosition= mp.getCurrentPosition();
            } catch (InterruptedException e) {
                return;
            } catch (Exception e){
                return;
            }            
            progressBar.setProgress(CurrentPosition);
        }
    }


}


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
  <Button id="@+id/Stop"  
            android:layout_width="125px" android:layout_height="50px"
            android:background="#FF222222" android:text="Start" />
  <Button id="@+id/StartMedia"  
            android:layout_width="125px" android:layout_height="50px"
            android:background="#FF222222" android:text="Start" />
   <ProgressBar id="@+id/progressBar"  
            android:layout_width="125px" android:layout_height="50px"
            android:background="#FF222222" android:text="Start"
            style="?android:attr/progressBarStyleHorizontal" />
  <TextView id="@+id/Status"  
            android:layout_width="125px" android:layout_height="50px"
            android:background="#FF222222" android:text="Start" />
</LinearLayout>

Answer 1

我认为当de Debugger尝试时你得到一个NPE： StartMedia.setOnClickListener（本）;

您应该尝试找到Stacktrace。

Answer 2

你说错误是

02-24 12:06:17.818: ERROR/AndroidRuntime(369): java.lang.RuntimeException: Unable to start activity ComponentInfo{kilbo.net/kilbo.net.Player}: java.lang.NullPointerException

您的活动是否在清单中正确宣布了？

应用程序意外停止

2 个答案: