Determining the type of a column

[Norman]

Hi guys,

I have a RadGrid which is populated dynamically by SQL queries at runtime.  I would like to add a total field for numeric columns in the footer, but since the column can be anything potentially, how do I programmatically determine the type of this column at runtime?  I'm aggregating the total in the RadGrid's ItemDataBound event and looking to potentially storing the total for each relevant column in a hash table (using the column name as the key).

Cheers,
Norman

[Princy]

Hello Norman,

Check out the following code snippet which shows how to find out the type of column and how to access its column UniqueName.

C#:

foreach (GridColumn col in RadGrid1.Columns)
       {
           if (col is GridNumericColumn)// checking for type of column
           {
              col.UniqueName//accessing column UniqueName
           }
       }

Thanks,
Princy.

[Norman]

Hi Princy,

Cheers for the help. I'm not entirely sure how your code listing will help me in this case.  Here's a snippet of code along the lines of what I was thinking of doing, which will hopefully clarify things:

Protected Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemDataBound

    If TypeOf e.Item Is GridDataItem Then

        ' If our field is of the right type, aggregate total for this column

        Dim dataItem As GridDataItem = CType(e.Item, GridDataItem)

        If ' Check if numeric...
' Add to total for this column

            totals(dataItem.ItemIndex).AddToTotal(' Converted type)

        End If

    ElseIf TypeOf e.Item Is GridFooterItem ' And numeric...

        ' If our field is of the right type, display a total for this column

        Dim footerItem As GridFooterItem = CType(e.Item, GridFooterItem)

        ' Read from total for this column

        footerItem("Total").Text = totals(footerItem.ItemIndex).ToString()

    End If

End Sub

Thanks for your help!

    Protected Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemDataBound

        If TypeOf e.Item Is GridDataItem Then

            ' If our field is of the right type, aggregate total for this column

            Dim dataItem As GridDataItem = CType(e.Item, GridDataItem)

            If TypeOf dataItem.DataItem Is Integer Then

                totals(dataItem.ItemIndex).AddToTotal(CType(dataItem.DataItem, Integer))

            ElseIf TypeOf e.Item.DataItem Is Double Then

                totals(dataItem.ItemIndex).AddToTotal(CType(dataItem.DataItem, Double))

            End If

        ElseIf TypeOf e.Item Is GridFooterItem And (TypeOf e.Item.DataItem Is Integer Or TypeOf e.Item.DataItem Is Double) Then

            ' If our field is of the right type, display a total for this column

            Dim footerItem As GridFooterItem = CType(e.Item, GridFooterItem)

            footerItem("Total").Text = totals(footerItem.ItemIndex).ToString()

        End If

    End Sub

[Veli]

Hi Norman,

Isn't it easier to just get the original data item that was used to bind the current GridDataItem instance?

Protected Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemDataBound
    If TypeOf e.Item Is GridDataItem Then
        Dim gridItem As GridDataItem = e.Item
        Dim sourceItem as Object = gridItem.DataItem
        'sourceItem is the original data source item used to bind the current
        'GridDataItem. You can cast it to the correct type (e.g. DataRowView)
        'and use its value for aggregation
    End IF
End Sub

This way, you can extract data values directly. If not, you need to parse the cell Text to the correct type in item cells:

Protected Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemDataBound
    If TypeOf e.Item Is GridDataItem Then
        Dim gridItem As GridDataItem = e.Item
        Dim numValStr As String = gridItem("NumericColumnName").Text
        Dim numVal As Double = Double.Parse(numValStr)
    End IF
End Sub

Veli
the Telerik team