我应该使用哪个上下文MediaPlayer.create()
?
我正在使用Activity.this
我的所有MediaPlayer
对象。但我认为它给了我空指针异常。
上下文可以成为在android或其他任何东西中强制关闭的原因吗?
这里“ com.bhavin.panara.kbc
”是包名。第 108 行是mediaplayer.start()
.
这是代码:
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