播放完媒体文件时的Android通知

Question

我有一个带有所有方法的mediaplayer类。 我只是想获得何时播放文件的指示，但是遇到了麻烦。 方法如下：

public boolean isPlaying()
{
    final boolean still_playing = true;
    mediaplayer.setOnCompletionListener(new OnCompletionListener() 
    {
        @Override
        public void onCompletion(MediaPlayer mp) 
        {
            still_playing = false;
        }
    });
    return still_playing;
}

我遇到错误，例如the final local variable cannot be assigned, since it is defined in an enclosing type或者当我尝试其他操作时，我得到了variabledeclaratorIdexpected

Answer 1

您的final boolean still_playing = true; 是一个常量变量，表示在运行时无法更改。

在程序的后面：

@Override
public void onCompletion(MediaPlayer mp) 
{
    still_playing = false;
}

您正在尝试更改其价值。

为了解决这个问题，您应该定义boolean still_playing = true; 作为sow这样的类的成员变量：

public class classExample {
    // member variables
    private boolean still_playing = true;

    public boolean isPlaying() {

        /* I DELETED THE VARIABLE AND DECLARED IT OUTSIDE THE METHOD */

        mediaplayer.setOnCompletionListener(new OnCompletionListener() {
             @Override
             public void onCompletion(MediaPlayer mp) {

                  /* You could declare it here too without the private
                     keyword like this:
                             boolean still_playing = true; */

                  still_playing = false;
             }
        });
        return still_playing;
    }
}