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这些是我的语法错误，我不知道如何弄清楚，

current_song 无法解析为变量

此行有多个标记，song_url 无法解析为变量

我如何解决上述错误。我无法在我的方法中访问 song_url 和 current_song，例如，

next.setOnClickListener(new View.OnClickListener(){
@Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            mp.stop();
            ++current_song;
            mp.setDataSource(song_url[current_song]);
            mp.start();
        }
    });

我的完整代码，

public class Jsonmedia extends Activity {
private MediaPlayer mp;
Button play, pause, next;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.jsonview);

    mp = new MediaPlayer();
    mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
    play = (Button) findViewById(R.id.play);
    pause = (Button) findViewById(R.id.pause);
    next = (Button) findViewById(R.id.next);

    try {
        // Create a URL for the desired page
        URL url = new URL("http://reallifethug.webs.com/temp_list.txt");
        BufferedReader in = new BufferedReader(new InputStreamReader(
                url.openStream()));

        int ch, current_song = 0, EOF = -1; // end of file
        String list[];

        String str = "";
        while ((ch = in.read()) != EOF)
            str += (char) ch;
        in.close();

        list = str.split("\n");

        for (ch = 0; ch < list.length; ++ch)
            list[ch] += "\n";

        String song_name[] = new String[list.length];
        String song_url[] = new String[list.length];

        for (int i = 0; i < list.length; i++) {
            song_name[i] = "";
            song_url[i] = "";
            int a = 0;
            char c;

            while ((c = list[i].charAt(a++)) != ' ')
                song_name[i] += c;

            while ((c = list[i].charAt(a++)) != '\n')
                song_url[i] += c;
        }
        mp.setDataSource(song_url[current_song]);
    } catch (IllegalArgumentException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (SecurityException 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.prepareAsync();
    play.setEnabled(false);
    mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
        @Override
        public void onPrepared(MediaPlayer mp) {
            // TODO Auto-generated method stub
            play.setEnabled(true);
        }
    });

    play.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            mp.start();
        }
    });

    pause.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            mp.pause();
        }
    });

    next.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            mp.stop();
            ++current_song;
            mp.setDataSource(song_url[current_song]);
            mp.start();
        }
    });

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.jsonmedia, menu);
    return true;
}

}

E/AndroidRuntime(486): 在 android.os.Looper.loop(Looper.java:123) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 android.app.ActivityThread.main(ActivityThread.java :3683) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 java.lang.reflect.Method.invokeNative(Native Method) 05-18 17:37:14.291: E/AndroidRuntime(486): 在java.lang.reflect.Method.invoke(Method.java:507) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java :839) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 05-18 17:37:14.291: E/AndroidRuntime (486): 在 dalvik.system.NativeStart.main(Native Method) 05-18 17:37:16.301: I/Process(486): 发送信号。PID：486 SIG：9 在 android.app.ActivityThread.main(ActivityThread.java:3683) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 java.lang.reflect.Method.invokeNative(Native Method) 05-18 17: 37:14.291: E/AndroidRuntime(486): 在 java.lang.reflect.Method.invoke(Method.java:507) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal .os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 05-18 17:37:14.291: E/AndroidRuntime(486): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 05-18 17:37:14.291: E/AndroidRuntime(486): at dalvik.system.NativeStart.main(Native Method) 05-18 17:37:16.301: I/Process(486): 发送信号。PID：486 SIG：9 在 android.app.ActivityThread.main(ActivityThread.java:3683) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 java.lang.reflect.Method.invokeNative(Native Method) 05-18 17: 37:14.291: E/AndroidRuntime(486): 在 java.lang.reflect.Method.invoke(Method.java:507) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal .os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 05-18 17:37:14.291: E/AndroidRuntime(486): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 05-18 17:37:14.291: E/AndroidRuntime(486): at dalvik.system.NativeStart.main(Native Method) 05-18 17:37:16.301: I/Process(486): 发送信号。PID：486 SIG：9 在 java.lang.reflect.Method.invoke(Method.java:507) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit. java:839) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 05-18 17:37:14.291: E/ AndroidRuntime(486): at dalvik.system.NativeStart.main(Native Method) 05-18 17:37:16.301: I/Process(486): 发送信号。PID：486 SIG：9 在 java.lang.reflect.Method.invoke(Method.java:507) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit. java:839) 05-18 17:37:14.291: E/AndroidRuntime(486): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 05-18 17:37:14.291: E/ AndroidRuntime(486): at dalvik.system.NativeStart.main(Native Method) 05-18 17:37:16.301: I/Process(486): 发送信号。PID：486 SIG：9 I/Process(486)：发送信号。PID：486 SIG：9 I/Process(486)：发送信号。PID：486 SIG：9

4

1 回答 1

0

您已在块song_url内部定义，try因此它在外部不可用。

所以在像之前声明它们try：

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.jsonview);

    mp = new MediaPlayer();
    mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
    play = (Button) findViewById(R.id.play);
    pause = (Button) findViewById(R.id.pause);
    next = (Button) findViewById(R.id.next);
    int current_song = 0;
    String song_url[] = null;

    try {
    ....
    ....
    song_url = new String[list.length];
}
于 2013-05-18T11:52:55.600 回答