爲什麼按鈕不起作用？

Question

有人可以解釋什麼是錯的？

我希望它能像這樣工作：

屏幕頂部的三個按鈕。當我按下按鈕1時，它應該顯示使＃1可見。當我按下按鈕2時，它應該顯示＃2並隱藏＃1和＃3，等等......我在每個內部都有不同的佈局。

片段CLASS：

public class Fragment1 extends Fragment implements View.OnClickListener { 

    public static Fragment newInstance(Context context) { 
     Fragment1 f = new Fragment1(); 

     return f; 
    } 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) { 
    ViewGroup root = (ViewGroup) inflater.inflate(R.layout.fragment_musikteori_symboler, null); 

    final Button button1 = (Button)getActivity().findViewById(R.id.button1); 
    button1.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      getActivity().findViewById(R.id.symb_id1).setVisibility(View.VISIBLE); 
      getActivity().findViewById(R.id.symb_id2).setVisibility(View.GONE); 
      getActivity().findViewById(R.id.symb_id3).setVisibility(View.GONE); 
     } 
    }); 

    final Button button2 = (Button)getActivity().findViewById(R.id.button2); 
    button2.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      getActivity().findViewById(R.id.symb_id1).setVisibility(View.GONE); 
      getActivity().findViewById(R.id.symb_id2).setVisibility(View.VISIBLE); 
      getActivity().findViewById(R.id.symb_id3).setVisibility(View.GONE); 
     } 
    }); 

    final Button button3 = (Button)getActivity().findViewById(R.id.button3); 
    button3.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      getActivity().findViewById(R.id.symb_id1).setVisibility(View.GONE); 
      getActivity().findViewById(R.id.symb_id2).setVisibility(View.GONE); 
      getActivity().findViewById(R.id.symb_id3).setVisibility(View.VISIBLE); 
     } 
    }); 

    return root; 
} 

佈局：

<LinearLayout 
android:orientation="vertical" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
android:background="@color/white" 
    xmlns:android="http://schemas.android.com/apk/res/android"> 



    <LinearLayout 
     android:orientation="horizontal" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content"> 

     <Button 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:text="Dynamik" 
      android:id="@+id/button1" 
      android:layout_weight="1"/> 


     <Button 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:text="Toner" 
      android:id="@+id/button2" 
      android:layout_weight="1"/> 

     <Button 
      android:layout_width="fill_parent" 
      android:layout_height="wrap_content" 
      android:text="Takter" 
      android:id="@+id/button3" 
      android:layout_weight="1"/> 

     </LinearLayout> 

<ScrollView 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:id="@+id/scrollView"> 

    <FrameLayout 
     android:layout_width="fill_parent" 
     android:layout_height="fill_parent"> 

     <include 
      android:id="@+id/symb_id1" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:visibility="visible" 
      layout="@layout/fragment_musikteori_symb_dynamik" /> 


     <include 
      android:id="@+id/symb_id2" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:visibility="gone" 
      layout="@layout/fragment_musikteori_symb_toner" /> 

     <include 
      android:id="@+id/symb_id3" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:visibility="gone" 
      layout="@layout/fragment_musikteori_symb_takter" /> 




     </FrameLayout> 
</ScrollView> 

</LinearLayout> 

錯誤......

01-24 14:38:51.341 5039-5039/com.myapp.test E/AndroidRuntime﹕ FATAL EXCEPTION: main 
Process: com.okramuf.musikteori, PID: 5039 
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myapp.test/com.myapp.test.testapp_main}: java.lang.NullPointerException 
     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2215) 
     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2265) 
     at android.app.ActivityThread.access$800(ActivityThread.java:145) 
     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1206) 
     at android.os.Handler.dispatchMessage(Handler.java:102) 
     at android.os.Looper.loop(Looper.java:136) 
     at android.app.ActivityThread.main(ActivityThread.java:5081) 
     at java.lang.reflect.Method.invokeNative(Native Method) 
     at java.lang.reflect.Method.invoke(Method.java:515) 
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:781) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
     at dalvik.system.NativeStart.main(Native Method) 
Caused by: java.lang.NullPointerException 
     at com.okramuf.musikteori.musikteori_main.onCreate(musikteori_main.java:51) 
     at android.app.Activity.performCreate(Activity.java:5231) 
     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2169) 
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2265) 
            at android.app.ActivityThread.access$800(ActivityThread.java:145) 
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1206) 
            at android.os.Handler.dispatchMessage(Handler.java:102) 
            at android.os.Looper.loop(Looper.java:136) 
            at android.app.ActivityThread.main(ActivityThread.java:5081) 
            at java.lang.reflect.Method.invokeNative(Native Method) 
            at java.lang.reflect.Method.invoke(Method.java:515) 
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:781) 
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
            at dalvik.system.NativeStart.main(Native Method) 

Answer 1

我沒有看到單擊操作的按鈕註冊。
和其他一些錯誤:)
旁觀教程這裏：http://developer.android.com/reference/android/widget/Button.html

你需要的東西是這樣的：

 final Button button = (Button) findViewById(R.id.button1); 
    button.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      // Perform action on click 
     } 
    }); 

，或者，如果你點擊監聽器，那麼你可以使用

 final Button button = (Button) findViewById(R.id.button1); 
    button.setOnClickListener(this); 

您在XML層中使用@+id/button1 ..然後在代碼中使用R.id.symb_id1，
I認爲這是錯誤的，然後修復View.GONE和switch命令.. 嘗試一些教程，然後再做一次。

Answer 2

如果在這裏找到一個解決方案：

Android Developers - Performing Fragment Transactions