Gridview Sorting event unhandled

Question

I have an asp gridview which is connected to my sql database via LINQ. I have it bound in the code behind. I also do the usual,

 AllowSorting="True"

and I set the sort expression for each column: ex-

                <asp:BoundField DataField="BorrowerDateOfBirth" HeaderText="Date Of Birth" 
                    DataFormatString="{0:d}" SortExpression="BorrowerDateOfBirth" >
                </asp:BoundField>

But when I run the application, and click the column headers to sort, the application fires an exception error that reads:

"The GridView 'gridview1' fired event Sorting which wasn't handled."

I looked this error up online but I only found responses related to C# code. I tried converting them to vb.net but the error still persisted.

Does anyone know how to handle sorting of an asp gridview in vb.net?

Answer 1

you need to set the OnSorting="" property to some function name, and then handle the sorting in said function. something along these lines

Protected Sub TaskGridView_Sorting(ByVal sender As Object, ByVal e As GridViewSortEventArgs)  
    'Retrieve the table from the session object.
    Dim dt = TryCast(Session("table"), DataTable)
    If dt IsNot Nothing Then 
      'Sorting the data.
      dt.DefaultView.Sort = e.SortExpression & " " &  GetSortingDirection(e.SortExpression)
      TaskGridView.DataSource = Session("TaskTable")
      TaskGridView.DataBind()
    End If
End Sub

Private Function GetSortingDirection(ByVal column As String) As String
    ' By default, set the sort direction to ascending.
    Dim sortDirection = "ASC"
    ' Retrieve the last column that was sorted.
    Dim sortExpression = TryCast(ViewState("SortExpression"), String)
    If sortExpression IsNot Nothing Then
      ' Check if the same column is being sorted.
      ' Otherwise, the default value can be returned.
      If sortExpression = column Then
        Dim lastDirection = TryCast(ViewState("SortDirection"), String)
        If lastDirection IsNot Nothing _
          AndAlso lastDirection = "ASC" Then
          sortDirection = "DESC"
        End If
      End If
    End If
    ' Save new values in ViewState.
    ViewState("SortDirection") = sortDirection
    ViewState("SortExpression") = column
    Return sortDirection
End Function