dataSource.getItemId（position）返回null

Question

我試圖獲取ListView成員的數據庫ID，以便我可以將它傳遞給一個新的活動，但SimpleCursorAdapter的.getItemId（位置）方法返回null，而不是數據庫中的_id。這是我的理解，這應該返回光標抓住_id字段，但它不適合我。也許需要一些建議

DatabaseHelper helper = new DatabaseHelper(this); 
    database = helper.getWritableDatabase(); 
    Cursor data = database.query("myDb", fields, null, null, null, null, null); 
    dataSource = new SimpleCursorAdapter(this, R.layout.row, data, fields, new int[] {R.id.idText, R.id.castName, R.id.castDescription}); 
    data.moveToFirst(); 

    final ListView view = getListView(); 

    view.setHeaderDividersEnabled(true); 
    view.addHeaderView(getLayoutInflater().inflate(R.layout.row, null)); 
    setListAdapter(dataSource); 


    database.close(); 

    view.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) { 


      // Prepare intent 
     Intent newActivity = new Intent(getApplicationContext(), ItemIdTester.class); 
      newActivity.putExtra("itemId",dataSource.getItemId(position)); 

      // start activity 
      startActivity(newActivity); 
      } 
     }); 

Answer 1

適配器是因爲添加的頭由

view.setHeaderDividersEnabled(true); 
view.addHeaderView(getLayoutInflater().inflate(R.layout.row, null)); 

返回null，我也開始直接從遊標得到我的數據。這裏是完整的onItemClickListener修復問題

view.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) { 

      Cursor cursor = (Cursor) dataSource.getItem(position-1); 

      Long itemId = cursor.getLong(0); 
      // Prepare intent 
      Intent newActivity = new Intent(getApplicationContext(), CastrRecorder.class); 
      newActivity.putExtra("itemId",itemId.toString()); 
      // start activity 
      startActivity(newActivity); 
      } 
     });