DataGrid and Sorting

[jesus4u]

Here is my scenario:

I want to use the in memory Data ONLY for the sorting...NO requerying of the database.

On Page load event I use a DataSet to DataBind to the DataGrid.
Then when I sort I use a DataView to sort then try to bind to the DataGrid using the DataView but the Page load event is firing again. So, how do I do a simple sort?

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If Not IsPostBack Then
            SqlDataAdapter1.SelectCommand.Parameters("@strDepartment").Value = "web"
            SqlDataAdapter1.Fill(Ds1)
            DataGrid1.DataBind()
        End If
    End Sub


    Private Sub DataGrid1_SortCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridSortCommandEventArgs) Handles DataGrid1.SortCommand
        Dim SortExpression As String = e.SortExpression.ToString()
        dv.Sort = SortExpression
        DataGrid1.DataSource = dv
        DataGrid1.DataBind()
    End Sub
End Class

[DevGrp]

In the Sort procedure you have to fill the DataSet again, or you can save the DataSet in a Session variable in the Page Load procedure, if you dont want to hit the DB again.

[jesus4u]

I tried this but still the datagrid comes up empty after I call the DataBind in the Sort Event.

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If Not IsPostBack Then
            SqlDataAdapter1.SelectCommand.Parameters("@strDepartment").Value = "web"
            SqlDataAdapter1.Fill(Ds1)
            DataGrid1.DataBind()
            Cache.Insert("ds", Ds1, Nothing, DateTime.Now.AddMinutes(5), Caching.Cache.NoSlidingExpiration)
        End If
    End Sub


    Private Sub DataGrid1_SortCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridSortCommandEventArgs) Handles DataGrid1.SortCommand
        Dim newdv As DataView = New DataView(Cache("ds"))
        Dim SortExpression As String = e.SortExpression.ToString()
        newdv.Sort = SortExpression & " asc"
        DataGrid1.DataSource = newdv
        DataGrid1.DataBind()
    End Sub
End Class

[jesus4u]

I got it to work!

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Grab cache and place into DataView
        dv = Cache("ds")
        'If cache is EMPTY
        If dv Is Nothing Then
            'Fill it up
            SqlDataAdapter1.SelectCommand.Parameters("@strDepartment").Value = "web"
            SqlDataAdapter1.Fill(Ds1)
            'Set DataView from the DataSet
            dv = New DataView(Ds1.Tables("GetAllContentByDept"))
            'Put DataView into cache
            Cache("ds") = dv
        End If
        DataGrid1.DataSource = dv
        DataGrid1.DataBind()
    End Sub


    Private Sub DataGrid1_SortCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridSortCommandEventArgs) Handles DataGrid1.SortCommand
        'Grab cache and place into DataView
        dv = Cache("ds")
        'Column Sorted
        Dim SortExpression As String = e.SortExpression.ToString()
        'Column and Direction ex. 'Column1 DESC'
        Dim strDGSortOrder As String = dv.Sort.ToString
        Dim strSortX As String = "ASC"
        'If ASC is found in the string 
        If strDGSortOrder.IndexOf("ASC") > 0 Then
            strSortX = "DESC"
        End If
        'Build sorting string 
        dv.Sort = SortExpression & " " & strSortX
        'Set DataSource
        DataGrid1.DataSource = dv
        'Re-bind
        DataGrid1.DataBind()
    End Sub
End Class

[DevGrp]

The SortExpression returns a string, so you dont have to call the ToString() method