android中的MediaPlayer.create()使用哪种上下文?
我应该将哪个上下文用于android中的MediaPlayer.create()使用哪种上下文?,android,performance,forceclose,Android,Performance,Forceclose,我应该将哪个上下文用于MediaPlayer.create() 我正在使用活动。此与我的所有MediaPlayer对象一起使用。但我认为它给了我空指针异常 在安卓系统中,上下文是强制关闭的原因吗 这里“com.bhavin.panara.kbc”是包名。 第108行是mediaplayer.start() 以下是代码: MediaPlayer mp; @Override protected void onCreate(Bundle savedInstanceState) { super.
MediaPlayer.create()
我正在使用活动。此
与我的所有MediaPlayer
对象一起使用。但我认为它给了我空指针异常
在安卓系统中,上下文是强制关闭的原因吗
这里“com.bhavin.panara.kbc
”是包名。
第108行是mediaplayer.start()
以下是代码:
MediaPlayer mp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
.
.
.
mp = MediaPlayer.create(PlayScreen.this, R.raw.sound);
.
.
mp.start(); // 108th line.
}
这是我的日志猫报告
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bhavin.panara.kbc/com.bhavin.panara.kbc.PlayScreen}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1999)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2026)
at android.app.ActivityThread.access$600(ActivityThread.java:127)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1174)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4506)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.bhavin.panara.kbc.PlayScreen.onCreate(PlayScreen.java:108)
at android.app.Activity.performCreate(Activity.java:4479)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1963)
... 11 more
试试这个-
MediaPlayer media=new MediaPlayer();
media.setDataSource(songname);
media.prepare();
media.start();
不,它表示一个空指针异常,所以可能它确实得到了文件的路径。 如果要使用媒体播放器,其中一种方法是:
MediaPlayer player = MediaPlayer.create(context, uri);
player.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
public void onCompletion(MediaPlayer mp) {
Log.d(TAG, "play Completed ...Starting Again ");
player.start();
}
});
player.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
public void onPrepared(MediaPlayer mp) {
Log.d(TAG, "preparation Completed ...playing ");
player.start();
}
});
发布如何初始化媒体播放器对象参见
PlayScreen.java
MediaPlayer mp=MediaPlayer.create(ActivityName.this,R.raw.music)的第108行;mp.start()//第108like@MrSuS行说你的问题不在于Mediaplayer,而在于加载酸痛。您没有加载PlayScreen。既然你没有发布你所有的代码,当我使用create方法时,没有人能帮你,也没有人能帮你准备和启动它。欢迎@Yogesh,你能再解释一下你在用代码做什么吗?
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//set the layout of the Activity
setContentView(R.layout.activity_songs);
//initialize views
initializeViews();
}
public void initializeViews(){
songName = (TextView) findViewById(R.id.songName);
songName.setText("khmosia.mp3");
mediaPlayer = MediaPlayer.create(this, Uri.parse("android.resource://" + getPackageName() + "/" + R.raw.khmosia));
mediaPlayer.start();
timeElapsed = mediaPlayer.getCurrentPosition();
finalTime = mediaPlayer.getDuration();
duration = (TextView) findViewById(R.id.songDuration);
timeElapsed = mediaPlayer.getCurrentPosition();
seekbar = (SeekBar) findViewById(R.id.seekBar);
seekbar.setProgress((int) timeElapsed);
durationHandler.postDelayed(updateSeekBarTime, 100);
seekbar.setMax((int) finalTime);
seekbar.setClickable(false);
Runnable updateSeekBarTime = new Runnable() {
public void run() {
//get current position
timeElapsed = mediaPlayer.getCurrentPosition();
//set seekbar progress
seekbar.setProgress((int) timeElapsed);
//set time remaing
double timeRemaining = finalTime - timeElapsed;
duration.setText(String.format("%d min, %d sec", TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining), TimeUnit.MILLISECONDS.toSeconds((long) timeRemaining) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining))));
//repeat yourself that again in 100 miliseconds
durationHandler.postDelayed(this, 100);
mediaPlayer.pause();
}
};