Dynamically adding DropDownList on edit on DataGridView asp.Net on the code

Question

Im working on a project just to add few things and one of thoose is to add a DropDownList on a GridView when they press the edit button of a row... Sadly the columns are added on runtime before the database binding, not on the aspx page as all the examples i found, i have it here like this:

private void SetColumnsGrid(GridView Grid)
    {
        BoundField Col = new BoundField();//1
        Col.HeaderText = "Name";
        Col.DataField = "Name";
        Col.HeaderStyle.Width = Unit.Pixel(100);
        Col.ReadOnly = true;
        Grid.Columns.Add(Col);

        Col = new BoundField(); //2
        Col.HeaderText = "User Type";
        Col.DataField = "UserType";
        Col.HeaderStyle.Width = Unit.Pixel(100);
        Grid.Columns.Add(Col);

        //Is ddl spected to be here as the TemplateField with the EditItemTemplate?
}

So, how can i do it? I just dont find the proper way. Whitch events should i handle?

Thank you very much

jason · Accepted Answer · 2013-03-27 11:26:50Z

There are several options you can use. One is to use a template, the other is to manually add the control when the row is created. Template example (this uses a checkbox but can easily be switched):

Public Class CheckBoxTemplate
    Implements ITemplate   

    Public Sub InstantiateIn(ByVal container As System.Web.UI.Control) Implements System.Web.UI.ITemplate.InstantiateIn
        Dim cb As CheckBox = New CheckBox()
        cb.ID = "someId"
        cb.AutoPostBack = True

        container.Controls.Add(cb)


    End Sub
End Class

In your app code, where you create the gridview control:

    Dim gv As New GridView
    With gv
        .ID = "myGridView"
        .AutoGenerateColumns = False
        .DataKeyNames = New String() {"somePKID"}
        .GridLines = GridLines.Both
        .AllowSorting = False
        .AllowPaging = False
        .PageSize = numRows
        .Width = tableWidth
        .BorderColor = Drawing.ColorTranslator.FromHtml("#808080")
        .PagerSettings.Mode = PagerButtons.NextPrevious
        .PagerSettings.NextPageText = "Next"
        .PagerSettings.PreviousPageText = "Prev"
        .HeaderStyle.CssClass = foundUserHeadStyle
        .RowStyle.CssClass = foundUserEvenRows
        .AlternatingRowStyle.CssClass = foundUserOddRows
        .Columns.Clear()

        Dim SelectUserTF As New TemplateField
        With SelectUserTF
            .HeaderText = "Add"
            .ItemStyle.Wrap = False
            .ItemTemplate = New CheckBoxTemplate()
        End With
       .Columns.Add(SelectUserTF)

   End With

Another option is to do this in the create row event:

     Protected Sub gv_rowCreated(ByVal sender As Object, ByVal e As GridViewRowEventArgs) Handles myGridView.RowCreated
    Try
        Dim myDDL As New DropDownList
        Dim myCollection As New ListItemCollection
        With myCollection
            Dim newItem As New ListItem
            newItem.Text = "item 1"
            newItem.Value = "1"

            .Add(newItem)
        End With
        e.Row.Cells(0).Controls.Add(myDDL)
  Catch ex As Exception

    Finally

    End Try
end sub

Let me know if this helps or if you have a question about it.

At the end i convinced my boss to do it on the old way. Anyways thanks for the help, we will have it in mind for the next time this issue comes out.

Collectives™ on Stack Overflow

Dynamically adding DropDownList on edit on DataGridView asp.Net on the code

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related