我可以將活動轉換爲片段嗎？

如何將此活動轉換爲片段？我已經轉換某些部分，但我得到的錯誤，這是我的實際代碼，任何人都可以提供幫助指正，我可以將活動轉換爲片段嗎？

public class GalleryActivity extends Fragment { 

    public Cursor cursor; 
    /* 
    * Column index for the Thumbnails Image IDs. 
    */ 
    public int columnIndex; 
    String imagePath; 
    MenuItem mSelectButton; 
    int mSelectSwitch; 
    private static final int MIN_DISTANCE = 100; 
    private static final int MAX_OFF_PATH = 200; 
    private static final int THRESHOLD_VELOCITY = 100; 
    private GestureDetector mGestureDetector; 
    private Context context; 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 
     return inflater.inflate(R.layout.activity_gallery, container, false); 
    } 

    @Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState);  

     String[] projection = {MediaStore.Images.Thumbnails._ID}; 
    //managedQuery causes an error 
     cursor = managedQuery(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,projection,null,null, 
       MediaStore.Images.Thumbnails.IMAGE_ID); 
     columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID); 
    //findViewById causes an error 
     GridView GalleryImages = (GridView) findViewById(R.id.galleryGrid1); 
     GalleryImages.setAdapter(new GalleryAdapter(this)); 
    // new GalleryAdapter(this) causes an error 
     GalleryImages.setOnItemClickListener(new OnItemClickListener() { 
      public void onItemClick(AdapterView parent, View v, int position, long id) { 
       mSelectButton.setVisible(true); 
       String[] imgData = {MediaStore.Images.Media.DATA}; 
       cursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,imgData, null,  
         null, 
         null); 
       columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA); 
       cursor.moveToPosition(position); 
       imagePath = cursor.getString(columnIndex); 
      } 
     }); 

    } 
    private class GalleryAdapter extends BaseAdapter { 

      private Context context; 

      public GalleryAdapter(Context localContext) { 
       context = localContext; 
      } 

      public int getCount() { 
       return cursor.getCount(); 
      } 
      public Object getItem(int position) { 
       return position; 
      } 
      public long getItemId(int position) { 
       return position; 
      } 
      public View getView(int position, View convertView, ViewGroup parent) { 
       ImageView picturesView; 
       if (convertView == null) { 
        picturesView = new ImageView(context); 
        // Move cursor to current position 
        cursor.moveToPosition(position); 
        // Get the current value for the requested column 
        int imageID = cursor.getInt(columnIndex); 
        // Set the content of the image based on the provided URI 
        picturesView.setImageURI(Uri.withAppendedPath(
          MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" + imageID)); 
        picturesView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
        picturesView.setLayoutParams(new GridView.LayoutParams(470,470)); 
       } 
       else { 
        picturesView = (ImageView)convertView; 
       } 
       return picturesView; 
      } 
     }

來源

2015-08-17 Blerim Blerii

我們需要看到你所得到的錯誤。請發佈Logcat –

編譯器上的錯誤不在logcat上，這是在managedQuery上：未定義類型new AdapterView.OnItemClickListener（）的方法managedQuery（Uri，String []，null，null，null）{ } –

下面是完整的代碼：

public class GalleryActivity extends Fragment { 

     public Cursor cursor; 
     /* 
     * Column index for the Thumbnails Image IDs. 
     */ 
     public int columnIndex; 
     String imagePath; 
     MenuItem mSelectButton; 
     int mSelectSwitch; 
     private static final int MIN_DISTANCE = 100; 
     private static final int MAX_OFF_PATH = 200; 
     private static final int THRESHOLD_VELOCITY = 100; 
     private GestureDetector mGestureDetector; 
     private Context context; 


     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View view = inflater.inflate(R.layout.activity_gallery, container, false); 
      String[] projection = {MediaStore.Images.Thumbnails._ID}; 
      //managedQuery causes an error 
      cursor = getActivity().managedQuery(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, projection, null, null, 
        MediaStore.Images.Thumbnails.IMAGE_ID); 
      columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID); 
      //findViewById causes an error 
      GridView GalleryImages = (GridView) view.findViewById(R.id.galleryGrid1); 
      GalleryImages.setAdapter(new GalleryAdapter(getActivity())); 
      // new GalleryAdapter(this) causes an error 
      GalleryImages.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
       @Override 
       public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
        mSelectButton.setVisible(true); 
        String[] imgData = {MediaStore.Images.Media.DATA}; 
        cursor = getActivity().managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, imgData, null, 
          null, 
          null); 
        columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA); 
        cursor.moveToPosition(position); 
        imagePath = cursor.getString(columnIndex); 
       } 
      }); 

      return view; 
     } 

     @Override 
     public void onActivityCreated(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 


     } 

     private class GalleryAdapter extends BaseAdapter { 

      private Context context; 

      public GalleryAdapter(Context localContext) { 
       context = localContext; 
      } 

      public int getCount() { 
       return cursor.getCount(); 
      } 

      public Object getItem(int position) { 
       return position; 
      } 

      public long getItemId(int position) { 
       return position; 
      } 

      public View getView(int position, View convertView, ViewGroup parent) { 
       ImageView picturesView; 
       if (convertView == null) { 
        picturesView = new ImageView(context); 
        // Move cursor to current position 
        cursor.moveToPosition(position); 
        // Get the current value for the requested column 
        int imageID = cursor.getInt(columnIndex); 
        // Set the content of the image based on the provided URI 
        picturesView.setImageURI(Uri.withAppendedPath(
          MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" + imageID)); 
        picturesView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
        picturesView.setLayoutParams(new GridView.LayoutParams(470, 470)); 
       } else { 
        picturesView = (ImageView) convertView; 
       } 
       return picturesView; 
      } 
     } 
    }

來源

2015-08-17 19:27:06 Aakash

非常感謝你！ –

請標記爲正確，如果它幫助你，謝謝:) – Aakash

我已經做到了！再次感謝！ –

不要使用managedQuery。看看用LoaderManager替換您的數據庫查詢。我相信managedQuery依賴於活動，所以如果你仍然想使用它，嘗試getActivity（）。managedQuery ....
用getActivity（）替換「this」;除非你需要Fragment上下文。大多數情況下需要一個活動上下文，所以使用getActivity。
findViewById需要在您在onCreateView中膨脹的視圖上執行。我建議重寫onViewCreated（）方法來執行所有的findViewById調用。注意！在傳入此方法的視圖上調用findViewById（）！這是你的碎片佈局！

來源

2015-08-17 19:25:45

我可以將活動轉換爲片段嗎？

回答

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