Set Focus to a Control in PopUp Edit Form of RadGrid

Description

Focusing the input control directly is a valid approach for other edit modes like EditForms and InPlace because they are generated inside the grid. However, the PopUp is loaded after the grid and the focus should be set in a later stage.

Solution

You can achieve this requirement using some time delay. First, access the generated edit control:
Accessing Controls in Edit/Insert Mode

Then, apply the focusing logic:

C#

protected void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
{
    if (e.Item is GridEditFormItem && e.Item.IsInEditMode)
    {
        GridEditFormItem form = (GridEditFormItem)e.Item;
        TextBox txtCustomer = (TextBox)form.FindControl("txtCustomer");
        string script = string.Format("setTimeout(function(){{$get('{0}').focus();}},150);", txtCustomer.ClientID);
        ScriptManager.RegisterStartupScript(Page, typeof(Page), "myScript", script, true);
    }
}

VB

Protected Sub RadGrid1_ItemDataBound(ByVal sender As Object, ByVal e As GridItemEventArgs)
    If TypeOf e.Item Is GridEditFormItem AndAlso e.Item.IsInEditMode Then
        Dim form As GridEditFormItem = CType(e.Item, GridEditFormItem)
        Dim txtCustomer As TextBox = CType(form.FindControl("txtCustomer"), TextBox)
        Dim script As String = String.Format("setTimeout(function(){{$get('{0}').focus();}},150);", txtCustomer.ClientID)
        ScriptManager.RegisterStartupScript(Page, GetType(Page), "myScript", script, True)
    End If
End Sub

JavaScript

function gridCreated(sender, args) {
    var editForm;
    var tableView = sender.get_masterTableView();
    if (tableView.get_isItemInserted()) {
        // insert mode active
        editForm = tableView.get_insertItem();
    }
    if (tableView.get_editItems().length > 0) {
        // edit mode active
        editForm = tableView.get_editItems()[0].get_editFormItem();
    }
    if (editForm) {
        // focus textbox
        var textBox = $telerik.findElement(editForm, "txtShipName");
        setTimeout(function () {
            textBox.focus();
        }, 150);
    }
}