Dynamic gridbuttoncolumn in dynamic radgrid event not firing

[Steven Webster]

Hi there

Could someone advise me how to create a gridbuttoncolumn to delete records in a dynamic radgrid that's generated on the fly. I'm using the code in this link as a reference - http://www.telerik.com/help/aspnet-ajax/grdchanginggridstructuredynamically.html, but can't get the command to fire.

I've added a hander for the item_command:

 

AddHandler grid.ItemCommand, AddressOf grid_ItemCommand

but I never get that far when the code runs.

Thanks in advance!!

Steven

[Princy]

Hello Steven,

The following code snippet shows how to add GridButtonColumn dynamically. You can also attach ItemCommand event to fire the Delete command.

C#:

protected void Page_Init(object sender, EventArgs e)
   {
       RadGrid grid = new RadGrid();
       grid.ID = "RadGrid1";
       //creating GridButtonColumn
       GridButtonColumn btncol = new GridButtonColumn();
       grid.MasterTableView.Columns.Add(btncol);
       btncol.ButtonType = GridButtonColumnType.LinkButton; // setting ButtonType as LinkButton
       btncol.CommandName = "Delete";
       btncol.Text = "delete";
       //attaching ItemCommand event
       grid.ItemCommand+=new GridCommandEventHandler(grid_ItemCommand);
       PlaceHolder1.Controls.Add(grid);
   }
 protected void grid_ItemCommand(object source, GridCommandEventArgs e)
   {
       if (e.CommandName == "Delete")
       {

       }
   }

And please go through the following documentation.
http://www.telerik.com/help/aspnet-ajax/grdprogrammaticcreation.html#Creating_the_grid_entirely_in_the_code_behind

Thanks,
Princy.

[Steven Webster]

Thanks Princy - much appreciated. I think I was adding the AddHandler in the wrong place. Anyways, bringing this a step further, based on the selection made in the dropdown list, a query is run that will return a resultset made up of multiple tables (with different columns in each). The code below works well to display the multiple dynamic radgrids and the delete command works, however, I get a "Failed to load viewstate" error intermittently when changing the value of the dropdown. I know it's because there are a different number of gridviews displayed with different id's depending on the option selected so I can't figure out which ones to rebind. Would you have any suggestions please?

Protected Sub Page_Init(ByVal sender As Object, _
  ByVal e As System.EventArgs) Handles Me.Init
    PopulateGridOnPageInit()
End Sub
Protected Sub PopulateGridOnPageInit()
    Dim literal1 As New Literal
    literal1.Text = "<br/><br/>"
    Dim ddlValue As String = Request.Form.Get("DropDownList1")
    Dim conn As New SqlConnection(ConfigurationManager.ConnectionStrings("StagingConnectionString").ConnectionString)
    Dim cmd As New SqlCommand()
    cmd.Connection = conn
    cmd.CommandType = CommandType.StoredProcedure
    cmd.CommandText = "spLookupChecksNew"
    If ddlValue Is Nothing Then
        ddlValue = DropDownList1.SelectedValue
    End If
    cmd.Parameters.Add(New SqlParameter("@Lab", SqlDbType.Int))
    'Assign the search value to the parameter.
    cmd.Parameters("@Lab").Value = ddlValue
    Dim da As SqlDataAdapter = New SqlDataAdapter(cmd)
    Dim ds As New DataSet()
    ds.Clear()
    ds.Tables.Clear()
    da.Fill(ds)
    Dim i As Integer = 0
    For Each DataTable In ds.Tables
        Dim grid As RadGrid = New RadGrid
        grid.ID = ddlValue.ToString + "grid" + i.ToString
        grid.Width = Unit.Pixel(500)
        grid.AllowSorting = True
        grid.PagerStyle.Mode = GridPagerMode.NextPrevAndNumeric
        grid.AllowPaging = True
        grid.Skin = "Sunset"
        grid.DataSource = ds.Tables(i)
        grid.MasterTableView.AutoGenerateColumns = False
        grid.MasterTableView.EnableColumnsViewState = False
        grid.MasterTableView.EnableViewState = False
        Dim boundColumn As GridBoundColumn
        Dim DeleteColumn As GridButtonColumn
        If Not (ddlValue Is Nothing) Then
            For Each DataColumn In ds.Tables(i).Columns
                boundColumn = New GridBoundColumn
                boundColumn.HeaderText = DataColumn.ToString
                boundColumn.DataField = DataColumn.ToString
                boundColumn.UniqueName = DataColumn.ToString
                grid.MasterTableView.Columns.Add(boundColumn)
            Next
            Dim btncol As GridButtonColumn = New GridButtonColumn
            grid.MasterTableView.Columns.Add(btncol)
            btncol.ButtonType = GridButtonColumnType.LinkButton
            ' setting ButtonType as LinkButton
            btncol.CommandName = "Delete"
            btncol.Text = "delete"
            'attaching ItemCommand event
            AddHandler grid.ItemCommand, AddressOf grid_ItemCommand
            Select Case ddlValue
                Case "0"
                    grid.DataSourceID = ""
                    grid.DataSource = New Object() {}
            End Select
            If ds.Tables(i).Rows.Count > 0 Then
                PlaceHolder1.Controls.Add(grid)
            End If
            PlaceHolder1.Controls.Add(literal1)
        Else
            grid.DataSourceID = ""
            grid.DataSource = New Object() {}
        End If
        i = i + 1
    Next
End Sub
Protected Sub DropDownList1_SelectedIndexChanged( _
               ByVal sender As Object, _
               ByVal e As EventArgs) _
         Handles DropDownList1.SelectedIndexChanged
    For Each childControl As Control In PlaceHolder1.Controls
        If TypeOf childControl Is RadGrid Then
            Dim grid As RadGrid = CType(childControl, RadGrid)
            grid.Rebind()
        End If
    Next
    'Dim grid As RadGrid = CType(PlaceHolder1.FindControl("grid"), RadGrid)
    'grid.Rebind()
End Sub
Protected Sub grid_ItemCommand(ByVal source As Object, ByVal e As GridCommandEventArgs)
    If e.CommandName = "Delete" Then
        ' Put delete commands in here ...
    End If
End Sub

[Iana Tsolova]

Hello Steven,

I suggest that you try binding the grid through its NeedDataSource event instead of just setting its DataSource on Page_Init and see if it makes any difference.

All the best,
Iana
the Telerik team