2011-11-17 57 views
1

我是android开发新手。我正在尝试制作一个简单的鼓声应用程序,当您点击特定的鼓时,它会播放特定的声音,但尚未完成,但我无法理解它为什么会一直崩溃。请帮帮我。下面的代码:Android应用程序无故崩溃

package com.android.stiggpwnz.drumset; 

    import android.app.Activity; 
    import android.media.MediaPlayer; 
    import android.os.Bundle; 
    import android.view.View; 
    import android.view.View.OnClickListener; 
    import android.widget.ImageView; 

    public class DrumSetActivity extends Activity { 
     /** Called when the activity is first created. */ 
     MediaPlayer ridesound = MediaPlayer.create(this, R.raw.ridecymbal); 
     MediaPlayer hatsound = MediaPlayer.create(this, R.raw.highhat); 

     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.main); 

      ImageView ride=(ImageView)findViewById(R.id.upLeftPlate); 
      ride.setOnClickListener(new OnClickListener() { 
       public void onClick(View v) { 
        ridesound.start(); 
       } 
      }); 

      ImageView highHat=(ImageView)findViewById(R.id.midLeftPlate); 
      highHat.setOnClickListener(new OnClickListener() { 
       public void onClick(View v) { 
        hatsound.start(); 
       } 
      }); 
     } 
    } 

这是我的布局:

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:background="@drawable/drumset" > 

    <ImageView 
     android:id="@+id/upLeftPlate" 
     android:layout_width="135dp" 
     android:layout_height="55dp" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentTop="true" 
     android:layout_marginLeft="31dp" 
     android:adjustViewBounds="true" 
     android:scaleType="fitXY" 
     android:src="@drawable/kh" /> 

    <ImageView 
     android:id="@+id/midLeftPlate" 
     android:layout_width="117dp" 
     android:layout_height="30dp" 
     android:layout_alignParentLeft="true" 
     android:layout_below="@+id/upLeftPlate" 
     android:layout_marginLeft="10dp" 
     android:layout_marginTop="22dp" 
     android:src="@drawable/kh" /> 

</RelativeLayout> 

这里的logcat的说什么:

11-17 20:55:56.349: E/AndroidRuntime(514): FATAL EXCEPTION: main 
11-17 20:55:56.349: E/AndroidRuntime(514): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.android.stiggpwnz.drumset/com.android.stiggpwnz.drumset.DrumSetActivity}: java.lang.NullPointerException 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.os.Handler.dispatchMessage(Handler.java:99) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.os.Looper.loop(Looper.java:123) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.app.ActivityThread.main(ActivityThread.java:4627) 
11-17 20:55:56.349: E/AndroidRuntime(514): at java.lang.reflect.Method.invokeNative(Native Method) 
11-17 20:55:56.349: E/AndroidRuntime(514): at java.lang.reflect.Method.invoke(Method.java:521) 
11-17 20:55:56.349: E/AndroidRuntime(514): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
11-17 20:55:56.349: E/AndroidRuntime(514): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
11-17 20:55:56.349: E/AndroidRuntime(514): at dalvik.system.NativeStart.main(Native Method) 
11-17 20:55:56.349: E/AndroidRuntime(514): Caused by: java.lang.NullPointerException 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.content.ContextWrapper.getResources(ContextWrapper.java:80) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.media.MediaPlayer.create(MediaPlayer.java:641) 
11-17 20:55:56.349: E/AndroidRuntime(514): at com.android.stiggpwnz.drumset.DrumSetActivity.<init>(DrumSetActivity.java:12) 
11-17 20:55:56.349: E/AndroidRuntime(514): at java.lang.Class.newInstanceImpl(Native Method) 
11-17 20:55:56.349: E/AndroidRuntime(514): at java.lang.Class.newInstance(Class.java:1429) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.app.Instrumentation.newActivity(Instrumentation.java:1021) 
11-17 20:55:56.349: E/AndroidRuntime(514): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577) 
11-17 20:55:56.349: E/AndroidRuntime(514): ... 11 more 

并能有人告诉我,为什么需要这么长的时间上传我的模拟器上的90KB应用程序?

[2011-11-17 21:10:36 - DrumSet] ------------------------------ 
[2011-11-17 21:10:36 - DrumSet] Android Launch! 
[2011-11-17 21:10:36 - DrumSet] adb is running normally. 
[2011-11-17 21:10:36 - DrumSet] Performing com.android.stiggpwnz.drumset.DrumSetActivity activity launch 
[2011-11-17 21:10:36 - DrumSet] Automatic Target Mode: using existing emulator 'emulator-5554' running compatible AVD 'bulat' 
[2011-11-17 21:10:36 - DrumSet] Uploading DrumSet.apk onto device 'emulator-5554' 
[2011-11-17 21:13:37 - DrumSet] Installing DrumSet.apk... 
[2011-11-17 21:13:51 - DrumSet] Success! 
[2011-11-17 21:13:51 - DrumSet] Starting activity com.android.stiggpwnz.drumset.DrumSetActivity on device emulator-5554 
[2011-11-17 21:13:54 - DrumSet] ActivityManager: Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.android.stiggpwnz.drumset/.DrumSetActivity } 

上传和安装90KB的东西之间的3 minuts。为什么?

+1

logcat说什么? – 2011-11-17 17:39:36

+0

它说很多东西,我没有得到它,我怎么能发送日志给你? –

+0

按红色的'E'按钮看红色的文字,它实际上显示类,方法和线条,甚至试图说出什么样的错误发生,所以它是工具#1使用 – 2011-11-17 17:48:53

回答

1

看看here, 注意下面的评论,这可能是你的问题。您没有遵循媒体播放器的正确调用层次结构。 浏览媒体播放器的state diagram

这里是完整的媒体播放器(播放音频)example

希望这会有所帮助。

+0

添加一个答案,只是说另一个答案是正确的,不会添加任何其他内容有什么意义?你应该有upvoted他,而不是 – Guillaume

+0

它没有帮助:( –

+0

男子我很机械的失望.. –

1

logCat表示尝试初始化您的活动时会引发异常。原因是从MediaPlayer获取资源时有NullPOinterException

对我而言,这意味着R.raw.ridecymbalR.raw.highhat中的任一个不存在。检查他们的案件,并确保他们真的存在(如果我正确地计算线路,可能是第一个:它说12行)。

+0

但他们确实存在,我可以玩并听到他们...... –

+0

然后你有没有试过在setContentView行之后移动你的activity的onCreate方法中的两个MediaPLayer行? – Guillaume

+0

是的,我做到了,但它一直崩溃 –

1

你可以尝试将这些二:

MediaPlayer ridesound = MediaPlayer.create(this, R.raw.ridecymbal); 
MediaPlayer hatsound = MediaPlayer.create(this, R.raw.highhat); 

是后的setContentView();

编辑: 这个问题可能是您正在尝试引用的MediaPlayer之前,它实际上是由活动本身引用,或您要设置一些结果还未被引用的组件

+0

你是什么意思?即时通讯不试图做任何非法:D 和是啊,我移动这些,它不断崩溃 除了上面的代码 –

+0

好吧,我试着布局在我的比较。一切正常,所以我假设问题是与MediaPlayer参考 – 2011-11-17 19:40:30

-1

您必须对创建的onCreate在MediaPlayer没有以前那么改变这两条线:

 MediaPlayer ridesound; 
     MediaPlayer hatsound; 

,并在你的onCreate实例化的MediaPlayer

 ridesound = MediaPlayer.create(this, R.raw.ridecymbal); 
    hatsound = MediaPlayer.create(this, R.raw.highhat); 

你已经更好地遵循androidtutorial的mediaplayer,因为你必须重写所有的代码... http://developer.android.com/guide/topics/media/mediaplayer.html