Question about grid, GridDropDownColumn and RadComboBox

[Marko]

Hi
We are using telerik grid which is build dynamically. When adding GridDropDownColumn to the grid it's working without problem. But one functionality is really not OK. When user click on the item in grid to change it, drop-down opens but drop down values are already filtered to the existing values. Combo box should work in different way, as it works here: https://demos.telerik.com/aspnet-ajax/combobox/examples/overview/defaultcs.aspx. When user clicks on that drop-down and if there is any item selected, he gets all items in dropdown and NOT pre-filtered by selected value.



How should we set up that column to allow out of the box behaviour of the Filter?

               GridDropDownColumn ddCol = new GridDropDownColumn();

               ddCol.DataSourceID = column.Name + "ObjectDataSource";
               ddCol.ListValueField = "ID";
               ddCol.ListTextField = "Name";
               ddCol.DataField = column.Name;
               ddCol.AllowAutomaticLoadOnDemand = true;
               ddCol.DropDownControlType = GridDropDownColumnControlType.RadComboBox;

[Marko]

for update...

 

The same functionality is presented here: 

When user clicks on "Supplier" for edit, the drop-down is allready pre-filtered for selected value. We want to have unfiltered values, as standard Rad combo box.

[Marko]

Missing link:

https://demos.telerik.com/aspnet-ajax/combobox/examples/functionality/comboingrid/defaultcs.aspx?product=combobox

[Attila Antal]

Hi Marko,

If I understand the request correctly, you do not want the RadComboBox to have pre-selected value when entering in Edit mode, is that correct?

In that case you can follow the approach from Accessing Controls in Edit/Insert Mode, bind the ItemDataBound event listener to RadGrid, access the RadComboBox within this event handler and clear the selection.

protected void Page_Init(object sender, EventArgs e)
{
        CreateGrid();
}

private void CreateGrid()
{
    RadGrid RadGrid1 = new RadGrid();
    RadGrid1.ID = "RadGrid1";
    RadGrid1.ItemDataBound += RadGrid1_ItemDataBound;

    GridDropDownColumn ddcol = new GridDropDownColumn();
    ddcol.DataField = "ShipCountry";
    ddcol.UniqueName = "ShipCountry";
    ddcol.HeaderText = "ShipCountry";
    ddcol.ListDataMember = "ShipCountry";
    ddcol.ListTextField = "ShipCountry";
    ddcol.ListValueField = "ShipCountry";
    RadGrid1.MasterTableView.Columns.Add(ddcol);

    // rest of the code

    PlaceHolder1.Controls.Add(RadGrid1);
}

private void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
{
    if(e.Item is GridEditableItem && e.Item.IsInEditMode)
    {
        var combo = (e.Item as GridEditableItem)["ShipCountry"].Controls[0] as RadComboBox;
        combo.Items.Insert(0, "All"); // You can even insert an item if you want
        combo.ClearSelection();
    }
}

Attached you can find a sample page demonstrating this scenario.

I hope this helps.

Kind regards,
Attila Antal
Progress Telerik