如何對ListViewAdapter的MergeCursor進行排序或重新排序

我正在爲我的案例研究開發一個簡單的社交媒體。我能夠從用戶關注的人員中檢索帖子。下面是截圖：如何對ListViewAdapter的MergeCursor進行排序或重新排序

正如你所看到的，問題是，職位沒有按照日期/編號的順序排列。相反，它是根據用戶關注的人進行分類的。這是因爲我只使用mergecursor合併遊標。以下是我的部分代碼：

ListView listviewFeed = (ListView) findViewById(R.id.listviewFeed); 
    Cursor cursorFeed = DataAdapters.getFeed(dbHelper, strUserID); 
    //This code is for retrieving user's own posts 

    Cursor cursorFollowing = DataAdapters.getFollowing(dbHelper,strUserID); 
    //This code is for retrieving the followed users. 

    if(cursorFollowing.getCount()>0) { 
     for (int intCtr = 0; intCtr < cursorFollowing.getCount(); intCtr++) { 
      int intUseridI = cursorFollowing.getColumnIndex(Tables.FollowTable.COLUMN_USERID); 
      String strUseridI = cursorFollowing.getString(intUseridI); 

      Cursor cursorFollowingFeed = DataAdapters.getFeed(dbHelper, strUseridI); 
      \\This code is for retrieving the posts of the people the user follows. 

      if(intCtr>0) 
      { 
       mergeCursor = new MergeCursor(new Cursor[]{mergeCursor, cursorFollowingFeed}); 
      }else { 
       mergeCursor = new MergeCursor(new Cursor[]{cursorFeed, cursorFollowingFeed}); 
      } 
      //This code is for merging the cursors. 

      if (intCtr + 1 == cursorFollowing.getCount()) { 
       cursorFollowing.close(); 
      } else { 
       cursorFollowing.moveToNext(); 
      } 
     } 
     ListViewAdapterMeasurement adapterMeasurement = new ListViewAdapterMeasurement(this, mergeCursor); 
     listviewFeed.setAdapter(adapterMeasurement); 
    }else 
    { 
     ListViewAdapterMeasurement adapterMeasurement = new ListViewAdapterMeasurement(this, cursorFeed); 
     listviewFeed.setAdapter(adapterMeasurement); 
    }

這一切都很好。我只想按日期或ID排列帖子。

有什麼辦法可以對MergeCursor進行排序嗎？

來源

2016-06-28 Junmar Calimbas Jose

不要使用MergeCursor ...添加'getAllFollowingFeeds'並使用INNER JOIN那裏 – Selvin

謝謝你的回答:)我已經設法解決了我的問題，你給了我一個想法來改變我的查詢:) @Selvin –

我想沒有辦法對MergeCursor進行排序，所以我試圖想出其他方法。

我改變了我的查詢是這樣的：

public static Cursor getFeed (DBHelper dbHelper, String strUserID) 
{ 
    SQLiteDatabase db = dbHelper.getReadableDatabase(); 
    Cursor cursorFollowing = getFollowing(dbHelper,strUserID); 

    String strQuery = "SELECT * FROM feed_tbl WHERE "+ Tables.FeedTable.COLUMN_USERID + "="+strUserID; 
    if(cursorFollowing.getCount()>0) 
    { 

     for(int intCtr=0;intCtr<cursorFollowing.getCount();intCtr++) 
     { 
      int intUseridI = cursorFollowing.getColumnIndex(Tables.FollowTable.COLUMN_USERID); 
      String strUseridI = cursorFollowing.getString(intUseridI); 
      String strConcatQuery = " OR "+ Tables.FeedTable.COLUMN_USERID + "="+strUseridI; 

      if (intCtr + 1 == cursorFollowing.getCount()) { 
       cursorFollowing.close(); 
      } else { 
       cursorFollowing.moveToNext(); 
      } 
      strQuery = strQuery +""+strConcatQuery; 
      Log.v(TAG,strQuery); 

     } 
    } 
    Cursor cursor = db.rawQuery(strQuery+" ORDER BY "+ Tables.FeedTable.COLUMN_ID + " DESC",null); 
    if (cursor != null) { 
     cursor.moveToFirst(); 
    } 
    return cursor; 
}

上的日誌標籤結果是這樣的：

V/FeedMe：SELECT * FROM feed_tbl WHERE feed_userid = 1或feed_userid = 2或feed_userid = 4或者feed_userid = 5

只是爲了讓那些與我有同樣問題的人明白，這是關於MergeCursor排序。有沒有這種方法來排序MERGECURSOR :)

謝謝！

來源

2016-06-28 12:55:28

如何對ListViewAdapter的MergeCursor進行排序或重新排序

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