Android照片庫

Question

我已經創建了一個應用程序與片段和畫廊片段，每當我打開它被關閉的片段。

以下是代碼：

的.xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:orientation="vertical" 
    android:layout_height="match_parent" 
    tools:context="junagadh.pkmcollege.com.pkmcollege.bscFragment"> 

    <Gallery 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/gallery1" 
     /> 

    <ImageView 
     android:layout_width="wrap_content" 
     android:layout_marginTop="25dp" 
     android:layout_height="wrap_content" 
     android:id="@+id/imageView1" 
     /> 



</LinearLayout> 

和編碼：

public class bscFragment extends Fragment { 

    int img[] = new int[5]; 
    public bscFragment() { 
     // Required empty public constructor 
    } 


    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     for(int i=0;i<img.length;i++) { 
      img[i]=getResources().getIdentifier("img"+i,"drawable",getActivity().getPackageName()); 
     } 

     final ImageView iv=(ImageView)getView().findViewById(R.id.imageView1); 
     iv.setImageResource(img[0]); 

     Gallery gal=(Gallery)getView().findViewById(R.id.gallery1); 
     gal.setAdapter(new ImageAdapter(getActivity())); 
     gal.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, int pos, long arg3) { 
       iv.setImageResource(img[pos]); 
      } 
     }); 

     // Inflate the layout for this fragment 
     return inflater.inflate(R.layout.fragment_bsc, container, false); 
    } 

    public class ImageAdapter extends BaseAdapter 
    { 
     Context c; 
     public ImageAdapter(Context c){ 
      this.c=c; 
     } 


     @Override 
     public int getCount() { 
      return img.length; 
     } 

     @Override 
     public Object getItem(int arg0) { 
      return arg0; 
     } 

     @Override 
     public long getItemId(int arg0) { 
      return arg0; 
     } 

     @Override 
     public View getView(int pos, View arg1, ViewGroup arg2) { 
      ImageView iv=new ImageView(c); 
      iv.setImageResource(img[pos]); 
      iv.setLayoutParams(new Gallery.LayoutParams(120,150)); 
      iv.setScaleType(ImageView.ScaleType.FIT_XY); 
      return iv; 
     } 
    } 

} 

日誌：

I/OpenGLRenderer: Initialized EGL, version 1.4 
E/EGL_emulation: tid 3280: eglSurfaceAttrib(1165): error 0x3009 (EGL_BAD_MATCH) 
W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xa237f040, error=EGL_BAD_MATCH 
D/AndroidRuntime: Shutting down VM 
E/AndroidRuntime: FATAL EXCEPTION: main 
        Process: junagadh.pkmcollege.com.pkmcollege, PID: 3263 
        java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference 
         at junagadh.pkmcollege.com.pkmcollege.bscFragment.onCreateView(bscFragment.java:34) 
         at android.support.v4.app.Fragment.performCreateView(Fragment.java:2189) 
         at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1299) 
         at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1528) 
         at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1595) 
         at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:757) 
         at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2355) 
         at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2146) 
         at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2098) 
         at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2008) 
         at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:710) 
         at android.os.Handler.handleCallback(Handler.java:739) 
         at android.os.Handler.dispatchMessage(Handler.java:95) 
         at android.os.Looper.loop(Looper.java:148) 
         at android.app.ActivityThread.main(ActivityThread.java:5417) 
         at java.lang.reflect.Method.invoke(Native Method) 
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
I/Process: Sending signal. PID: 3263 SIG: 9 
Application terminated. 

我想創建一個照片庫一個畫廊和Imag EVIEW。在圖庫中，它將顯示名稱爲img0，img1，img2等的可繪製文件夾中的所有圖像...並且所選圖像將顯示在圖像視圖上。

有人幫我解決這個問題。

謝謝:)

Answer 1

您可以首先充氣視圖並從充氣視圖中獲取物品。然後返回你膨脹的視圖。鑑於錯誤日誌中的空指針異常，下面的內容應該可以工作。

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
View view = inflater.inflate(R.layout.fragment_bsc, container, false); 
    for(int i=0;i<img.length;i++) { 
     img[i]=getResources().getIdentifier("img"+i,"drawable",getActivity().getPackageName()); 
    } 

    final ImageView iv=(ImageView)view.findViewById(R.id.imageView1); 
    iv.setImageResource(img[0]); 

    Gallery gal=(Gallery)view.findViewById(R.id.gallery1); 
    gal.setAdapter(new ImageAdapter(getActivity())); 
    gal.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> arg0, View arg1, int pos, long arg3) { 
      iv.setImageResource(img[pos]); 
     } 
    }); 

    return view; 
}