FlexGrid sort iComparer

FlexGrid sort iComparer

Posted by: fsegui on 21 February 2022, 1:12 pm EST

• 

  fsegui

  • Post Options:
  • Link
    Copy

  Posted 21 February 2022, 1:12 pm EST

  Hi,

  I try to use a specific iComparer to sort a FlexGrid, but it’s not taken into account. The column is not sorted at all.

  See sample attached.
  
  GroupPanelUpdate_FG.zip

  Thanks,
  
  Regards

• 

  wknauf

  • Post Options:
  • Link
    Copy

  Posted 22 February 2022, 4:29 am EST

  Hi,

  there is a small typo in the sample that breaks sorting: the check should be for col index 2 instead of 3:

      Private Sub flex_BeforeSort(sender As Object, e As SortColEventArgs) Handles C1FlexGrid1.BeforeSort
      If e.Col = 2 Then
        C1FlexGrid1.Sort(New ExampleComparer(C1FlexGrid1, e.Order, e.Col))
        e.Handled = True
      End If
    End Sub
  

  After this change, it worked.

  Best regards

  Wolfgang

• 

  fsegui

  • Post Options:
  • Link
    Copy

  Posted 22 February 2022, 4:42 am EST - Updated 3 October 2022, 10:39 pm EST

  Hello Wolfgang,
  
  Actually I want to sort using the iComparer on the column 3 (not alphabetical order)

  If you set to col index 2, it sort using the alphabetical order.

• 

  wknauf

  • Post Options:
  • Link
    Copy

  Posted 22 February 2022, 5:54 am EST

  Oh, my bad - I had converted the sample to a version without data binding, and had missed the fixed column. Thus I had a different column index.

  The doc for C1FlexGrid.Sort says:
  
  Custom sorting can only be used when the grid is in unbound mode.

  So I assume it is not actually supported. Attached sample creates an unbound grid, and here sorting works as expected.
  
  GroupPanelUpdate_FG_new.zip

  For sorting the DataTable, you would probably have to set “DataTable.DefaultValue.Sort” to a column index (similar to the “order by” part of a SQL “select” statement). But this is probably not possible in your “real world” app?

  Best regards

  Wolfgang

• 

  fsegui

  • Post Options:
  • Link
    Copy

  Posted 22 February 2022, 8:46 am EST

  I’ve not seen that in the documentation:
  
  https://www.grapecity.com/componentone/docs/win/online-flexgrid/sort-operations.html#6
  
  Is it mentioned elsewhere?
  
  I could add a column with an “index” but I’m afraid that’ll have side effects.

• 

  avnish.kumar

  

  • Post Options:
  • Link
    Copy

  Posted 22 February 2022, 9:01 am EST

  Hi Florent,

  The Custom sorting can only be used when the grid is in Unbound mode, as mentioned in the documentation comments of the C1FlexGrid.Sort method.
  
  Documentation: https://www.grapecity.com/componentone/docs/win/online-flexgrid/C1.Win.C1FlexGrid.4.5.2~C1.Win.C1FlexGrid.C1FlexGridBase~Sort(IComparer).html

  In Bound mode you will need to sort the data source itself, since DataTable/DataView does not support custom sorting, you will need to sort the data rows and create a new sorted data view that you can then assign to the grid.

  Regards.
  
  Avnish
  
  GroupPanelUpdate_FG_mod.zip

• 

  fsegui

  • Post Options:
  • Link
    Copy

  Posted 22 February 2022, 10:32 am EST

  Hi Avnish,

  Thanks for your updated sample.
  
  I’ve played with it and it seems when grouping the sort is lost.

  Regards,
  
  Florent

• 

  fsegui

  • Post Options:
  • Link
    Copy

  Posted 22 February 2022, 10:33 am EST

  Another question: is it possible to sort according to the userdata? (in bound mode).

• 

  avnish.kumar

  

  • Post Options:
  • Link
    Copy

  Posted 23 February 2022, 7:06 am EST

  Hi,

  To Custom sort the column while grouping, you can copy the GroupDescriptions in a list and then Clear the GroupDescriptions before sorting. Then after the sorting is done, you can apply the GroupDescriptions again.

  Since moving rows is not allowed in bound mode, It is not directly possible to sort the Grid on the basis of UserData while in bound mode. As a workaround, you can add a custom column in your DataTable and hide that column from the Grid. Then, you can add your UserData in this column and use values from this column while comparing the Rows in the Custom sort.
  
  Kindly refer to the updated sample. In the sample, sorting the position column sorts on the basis of hidden User Data column. [GroupPanelUpdate_FG_UserDataSort.zip]

  Regards.
  
  Avnish

  GroupPanelUpdate_FG_UserDataSort.zip