android 应用程序中的“E/ExtMediaPlayer-JNI：env->IsInstanceOf 失败”错误

Question

我尝试通过不断更改文本视图的文本并将其设置为 mediaPlayer.getCurrentPosition() 来在播放歌曲时查看时间。但是当我在设备上运行时，应用程序打开但没有响应。这是安装后的logcat。

**6-23 18:16:20.751 21850-21850/com.nitescorp.myapplication W/System: ClassLoader referenced unknown path: /data/app/com.nitescorp.myapplication-2/lib/arm64
06-23 18:16:20.754 21850-21850/com.nitescorp.myapplication I/InstantRun: starting instant run server: is main process
06-23 18:16:20.757 21850-21850/com.nitescorp.myapplication I/ActivityThreadEui: Handling launch of ActivityRecord{1cfdf61 token=android.os.BinderProxy@be10f47 {com.nitescorp.myapplication/com.nitescorp.myapplication.MainActivity}} startsNotResumed=false
06-23 18:16:21.039 21850-21850/com.nitescorp.myapplication E/ExtMediaPlayer-JNI: env->IsInstanceOf fails
06-23 18:16:21.039 21850-21850/com.nitescorp.myapplication E/MediaPlayer-JNI: JNIMediaPlayerFactory: bIsQCMediaPlayerPresent 0
06-23 18:16:21.039 21850-21850/com.nitescorp.myapplication E/ExtMediaPlayer-JNI: env->IsInstanceOf fails
06-23 18:16:21.039 21850-21850/com.nitescorp.myapplication E/MediaPlayer-JNI: JNIMediaPlayerFactory: bIsQCMediaPlayerPresent 0
06-23 18:16:21.142 21850-21920/com.nitescorp.myapplication I/Adreno: QUALCOMM build                   : 7a841e6, I43097da1fb
                                                                     Build Date                       : 05/10/16
                                                                     OpenGL ES Shader Compiler Version: XE031.06.00.02
                                                                     Local Branch                     : mybranch19687176
                                                                     Remote Branch                    : quic/LA.BR.1.3.3.c4
                                                                     Remote Branch                    : NONE
                                                                     Reconstruct Branch               : NOTHING
06-23 18:16:21.146 21850-21920/com.nitescorp.myapplication I/OpenGLRenderer: Initialized EGL, version 1.4
06-23 18:16:27.897 21850-21850/com.nitescorp.myapplication I/ViewRootImpl: finishMotionEvent: handled = false stage=11: Synthetic input stage,inputElapseTime=1 eventTime = 217132137 downTime = 217132137 title= com.nitescorp.myapplication/com.nitescorp.myapplication.MainActivity
06-23 18:21:25.725 21850-21850/com.nitescorp.myapplication I/ViewRootImpl: finishMotionEvent: handled = false stage=11: Synthetic input stage,inputElapseTime=2 eventTime = 217429055 downTime = 217429055 title= com.nitescorp.myapplication/com.nitescorp.myapplication.MainActivity**

这是java代码

import android.content.Context;
import android.media.MediaPlayer;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.View.*;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {
    public Context context = MainActivity.this;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final MediaPlayer mediaPlayer = MediaPlayer.create(this, R.raw.lovemelikeyoudo);

        OnClickListener onClickListenerPlay = new OnClickListener() {
            @Override
            public void onClick(View v) {


                mediaPlayer.start();
                TextView current = (TextView)findViewById(R.id.current_time);
                current.setVisibility(View.VISIBLE);

                TextView of = (TextView)findViewById(R.id.of);
                of.setVisibility(View.VISIBLE);

                TextView total = (TextView)findViewById(R.id.total_length);
                current.setVisibility(View.VISIBLE);
                total.setText( String.valueOf(mediaPlayer.getDuration()) );

                showTime(mediaPlayer);


            }
        };

        OnClickListener onClickListenerPause = new OnClickListener() {
            @Override
            public void onClick(View v) {


                mediaPlayer.pause();



            }
        };

        Button play = (Button)findViewById(R.id.play);
        play.setOnClickListener( onClickListenerPlay);

        Button pause = (Button)findViewById(R.id.pause);
        pause.setOnClickListener(onClickListenerPause);

        mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            public void onCompletion(MediaPlayer mediaPlayer) {
                Context context = getApplicationContext();
                CharSequence text = "The song is finished";
                int duration = Toast.LENGTH_SHORT;

                Toast toast = Toast.makeText(context, text, duration);
                toast.show();

                LinearLayout showTime = (LinearLayout)findViewById(R.id.time_view);
                showTime.setVisibility(View.GONE);

            }
        });
        }

       public void showTime(MediaPlayer mediaPlayer){
        while (mediaPlayer.isPlaying()){

        TextView current = (TextView)findViewById(R.id.current_time);
        current.setText(String.valueOf(mediaPlayer.getCurrentPosition())  );

        }
        }



}

问题出在 showTime 方法上，当我评论说应用程序没有显示这些错误时

public void showTime(MediaPlayer mediaPlayer){
        while (mediaPlayer.isPlaying()){

        TextView current = (TextView)findViewById(R.id.current_time);
        current.setText(String.valueOf(mediaPlayer.getCurrentPosition())  );

        }
        }