我正在尝试在我的应用中使用媒体播放器,并且试图阻止我的编码正在执行的其他活动使媒体播放器:
FirstActivity:
public void stop() {
if (playPause == false) {
control.setBackgroundResource(R.drawable.play);
mediaPlayer.stop();
new Player().cancel(true);
media.stop();
media.reset();
mediaPlayer.reset();
if (mediaPlayer.isPlaying())
mediaPlayer.stop();
mediaPlayer.reset();
media.stop();
playPause = true;
} else {
control.setBackgroundResource(R.drawable.pause);
if (intialStage) {
new Player()
.execute(URL);
} else {
if (!mediaPlayer.isPlaying())
mediaPlayer.start();
}
playPause = false;
}
}
第二活动:
必须在计时器结束后停止媒体播放器:
@Override
public void onFinish() {
textViewTime.setText(hmsTimeFormatter(timeCountInMilliSeconds));
// call to initialize the progress bar values
setProgressBarValues();
// hiding the reset icon
imageViewReset.setVisibility(View.GONE);
// changing stop icon to start icon
imageViewStartStop.setImageResource(R.drawable.icon_start);
// making edit text editable
editTextMinute.setEnabled(true);
// changing the timer status to stopped
timerStatus = TimerStatus.STOPPED;
MainActivity main = new MainActivity();
main.stop();
}
}.start();
countDownTimer.start();
}
以上编码显示错误:
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setBackgroundResource(int)' on a null object reference
at com.digitamatix.mukilfm.MainActivity.stop(MainActivity.java:549)
我必须在第一次活动中停止媒体播放器,请帮助我编码以解决问题
请参阅我已通过startActivityForResult
(基于您发布的代码)