Bind Column ValueList directly to a DataTable

470

Michael Strohmayer posted over 16 years ago

Hi,

I have a hierarchical grid, which is bound to a dataset via the DataBind method.

On certain columns I have to display the text in stead of numbers.

I do this at the moment in creating valuelists for these columns by looping thru the rows of a datatable.

Somtimes I need the same valuelists in two columns but different bands or even in two grids on the same form.

To get this working I have to clone the valulists otherwise I get a runtime error.

I'm wondering if there is no way to bind a valuelist of acolumn directly to the dataset.

460

Mendel posted over 16 years ago

i'v built this function with 4 overloads, you pass a dt it returns as valuelist
Public Overloads Shared Function getLookupValueList(ByVal lkpdt As DataTable, ByVal displayCol As String, ByVal isExpr As Boolean) As ValueList
Return getLookupValueList(lkpdt, displayCol, isExpr, String.Empty, False)
End Function

Public Overloads Shared Function getLookupValueList(ByVal lkpDT As DataTable, ByVal displayCol As String, ByVal isExpr As Boolean, ByVal filter As String) As ValueList
Return getLookupValueList(lkpDT, displayCol, isExpr, filter, False)
End Function

Public Overloads Shared Function getLookupValueList(ByVal lkpDT As DataTable, ByVal displayCol As String, ByVal isExpr As Boolean, ByVal sort As Boolean) As ValueList
Return getLookupValueList(lkpDT, displayCol, isExpr, String.Empty, sort)

End Function
Public Overloads Shared Function getLookupValueList(ByVal lkpDT As DataTable, ByVal displayCol As String, ByVal isExpr As Boolean, ByVal filter As String, ByVal sort As Boolean) As ValueList
'same as above, but it filters the datatable by the given filter value

If isExpr Then
lkpDT.Columns.Add("expr", GetType(String), displayCol)
displayCol = "expr"

End If
Dim myRows As DataRow()
If filter = String.Empty Then

If sort = True Then

myRows = lkpDT.Select("TRUE=TRUE", displayCol)

Else

myRows = lkpDT.Select()

End If

Else

If sort = True Then

myRows = lkpDT.Select(filter, displayCol)

Else

myRows = lkpDT.Select(filter)

End If

End If
Dim myVL As New ValueList
myVL.Key = lkpDT.TableName
For Each row As DataRow In myRows
If Not row.RowState = DataRowState.Deleted Then myVL.ValueListItems.Add(row.Item(0), row.Item(displayCol).ToString)

Next

If myVL.ValueListItems.Count = 0 Then

myVL.ValueListItems.Add(0, "**No Items In List**")
End If

If isExpr Then

lkpDT.Columns.Remove("expr")

End If
Return myVL
End Function
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470

Offline Michael Strohmayer posted over 16 years ago in reply to Mendel

That is a quite nice solution.
Havn't thought on doing it this way.
But anyway it would be much easier if You could bind it like on a combo box.
Many Thanks
I try to fiure it on my solution
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390

Offline Lyle Hardin posted over 16 years ago in reply to Michael Strohmayer

Have you tried the UltraDropDown control, it is like the UltraCombo but is for use with the columns of an UltraGrid?
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469350

Offline Mike Saltzman posted over 16 years ago in reply to Lyle Hardin

The UltraDropDown might be a good solution. Also, what is the error you get when you try to use the same ValueList in different grids? I think there might be a problem if you create a ValueList in the grid's ValueLists collection and try to use it in another grid. But if you just declare a new ValueList object in code, I would think it would work with two different grids just fine. I could be wrong.
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470

Offline Michael Strohmayer posted over 16 years ago in reply to Mike Saltzman

Yes You are wrong.
I create Valuelists in code and assign them to coulumns and the error appears and says that the appearance must be the same as used before.
That is nonsens.
If I just reassigns the programmatically established list to the local object before assigning it to a gird column the stupid error does not appear.
I 'm not quite sure what causes this behaviour, but reassigning the same valuelist to the same local object cures the problem.
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