I still haven't found a solution to this problem: https://www.telerik.com/forums/cellvalidating-event-question

asked
1. When user inputs an invalid value for a cell, we can use ErrorText to show an error message in the RowHeaderColumn.
 Normally, the ErrorText will be cleared after the user corrects the value. Sometimes the user will just press Esc key to cancel the input value, in this case the CellValidating event won't get fired and the ErrorText will remain shown on the RowHeaderColumn. This behavior will make the user feel confused.
answered
1. CellValidating event occurs only when a cell value is changed. In case when Esc is pressed, the value remains the same and no validation is needed. However, you can handle CellEndEdit event in this case and reset the ErrorText property.

Private Sub grdURLs2_UserAddingRow(sender As Object, e As GridViewRowCancelEventArgs) Handles grdURLs2.UserAddingRow
    Try
        If TypeOf e.Rows(0) Is GridViewNewRowInfo AndAlso
        TryCast(e.Rows(0).Cells(0).ColumnInfo, GridViewDataColumn) IsNot Nothing AndAlso
           TryCast(e.Rows(0).Cells(1).ColumnInfo, GridViewDataColumn) IsNot Nothing Then
            If e.Rows(0).Cells(0).Value Is Nothing OrElse
            String.IsNullOrEmpty(Trim(e.Rows(0).Cells(0).Value)) Then
                e.Cancel = True
                DirectCast(e.Rows(0), GridViewNewRowInfo).ErrorText = "Empty!"
            ElseIf e.Rows(0).Cells(1).Value Is Nothing OrElse
                String.IsNullOrEmpty(Trim(e.Rows(0).Cells(1).Value)) Then
                e.Cancel = True
                DirectCast(e.Rows(0), GridViewNewRowInfo).ErrorText = "Empty!"
            ElseIf e.Rows(0).Cells(1).Value IsNot Nothing Then
                For Each row In grdURLs2.Rows
                    If e.Rows(0).Cells(1).Value = row.Cells(1).Value Then
                        e.Cancel = True
                        DirectCast(e.Rows(0), GridViewNewRowInfo).ErrorText = "Exists!"
                    End If
                Next
            End If
        End If
    Catch ex As Exception
        txtError.Text = ex.Message & " - " & Format(Now, "HH:mm:ss")
    End Try
End Sub

Private Sub grdURLs2_CellEndEdit(sender As Object, e As GridViewCellEventArgs) Handles grdURLs2.CellEndEdit
    Try
        If TypeOf e.Row Is GridViewNewRowInfo Then
            DirectCast(e.Row, GridViewNewRowInfo).ErrorText = String.Empty
        End If
    Catch ex As Exception
        txtError.Text = ex.Message & " - " & Format(Now, "HH:mm:ss")
    End Try
End Sub
This doesn't work. The CellEndEdit event does not fire.

Hi Support Team,

I am having difficulties using WinForms UI components in combination with System.Windows.Forms.TableLayoutPanel. I wanted to follow the suggestions of using this panel to create HDPI aware UIs.

Component nesting is like this:

• RadForm
  • RadLayoutControl
    • LayoutControlTabbedGroup
      • LayoutControlGroupItem1
      • LayoutControlGroupItem2
        • LayoutControlItem1
          • TableLayoutPanel1
    • LayoutControlItem2
      • TableLayoutPanel2
    • LayoutControlItem3
      • RadButton1

When I am in the default "CSharp Form Editor" I'm not able to place the UI components into the TableLayoutPanel. The designer always tries to create a new LayoutControlItem in the RadLayoutControl. E.g. when trying to add a RadButton into the TableLayoutPanel2, it creates the RadButton1 right next to the TableLayoutPanel2 (or below/above;) into a new LayoutControlItem3, but not IN the desired column/row of the TableLayoutPanel2.

I tried a workaround by creating a standard Form and placing a TableLayoutPanel into it. Then adding all the UI components I want in it and afterwards copy+paste it into the LayoutControlGroupItem of another RadForm. However this approach seems to not attach it to any LayoutControlItem by using the Designer. It just gets added to the RadLayoutControl. I then tried to manually write the Designer Code by looking at how the Example code is generated, but that also is not reliable and I'm having an issue with getting the TableLayoutPanel docked to the "manually created" LayoutControlItem.

My question:

1. How can I get this to work or is this combination not intended/supported?

Environment

• Visual Studio 2022 v17.12.4
• .NET Framework 4.8
• Telerik WinForms UI 2024.4.1113.48

Added my example project and a screenshot of the designer while dragging a new RadLabel (or similar) onto the TableLayoutPanel.

Edit1: Added another screenshot of intended behavior.

Thanks and regards,

Kai

I use the following code to group and format the group name.

Private Sub grdURLs2_GroupSummaryEvaluate(sender As Object, e As GroupSummaryEvaluationEventArgs) Handles grdURLs2.GroupSummaryEvaluate
    Try
        Dim groupRow As GridViewGroupRowInfo = TryCast(e.Context, GridViewGroupRowInfo)
        If e.SummaryItem.Name = "col1" Then
            If groupRow IsNot Nothing Then
                If e.Value IsNot Nothing Then
                    e.FormatString = e.Value
                Else
                    e.FormatString = ""
                End If
            End If
        End If
    Catch ex As Exception
        txtError.Text = ex.Message & " - " & Format(Now, "HH:mm:ss")
    End Try
End Sub

Everything works fine until I leave the group field empty. This code works fine with an empty field, but after restarting the program, it adds records with empty fields not to the same group, but creates a new one. After restarting the program, all fields are in the same group. What am I doing wrong and how can I do it right? Thank you!

P.S.: I figured out why this happens.

Then another question arises. How to check cells for empty values ​​when adding a record and not add records with empty cells (continue editing)? Or replace empty values ​​in cells with significant ones and add?

I am trying to programmatically set the width of the dropdown list when the user clicks the DropDownButton, but my items are getting cut off because I can't seem to find the width of the CheckBox on the list so I can pad the width. How can I get to that information?

TIA.

Mark

Hi there!

Recently i encountered the following error: 'You are trying to use a multi-threaded .NET object in a way that is not supported.  The ABL cannot be called on a thread other than the main thread.'. I've known for a while that the language used in my company doesn't support multi-tread, that's why we usually used the version '20' of the dll's but sometimes the "40" were also usable even being multi-thread. Check the following link for context.

However, after updating the 2020 dll's to the 2023, we've been encountering several problems with the "RadPivotGrid" object. We get constant errors and warnings (like the one i shared). So, I've been trying unsuccessfully to find the '20' version so i can force my company's application to run with a single thread, and i can't find it anywhere.

Can anyone help me find it? Preferably DLL's from the year 2023 and forward.

Thank you.

JP

Hello,

I would like to have combo box column in GridView editable by user, so user can select from dropdown list or type it manually. I have two possible scenarios, one with column mapped to other table, so it should be really only some value from dropdown, but I want to have it editable because of more values, and second with just string value, but I want to offer a dropdown for selecting most common values. It doesn't work in any case. Selecting from dropdown list is ok, but when I type an option manually, it reverts back to original value:

I have found very similar question here, but it's older and I don't know, how he solved it, it doesn't work for me, or more precisely, I don't know what's the difference, I don't see any important point I have missed.
https://www.telerik.com/forums/editable-gridviewcomboboxcolumn
https://docs.telerik.com/devtools/winforms/controls/gridview/features/editing/editors/how-to/allow-end-users-to-add-items-to-dropdownlisteditor

I have column defined like this:

dc = new DbDataContext();
var col = rgv.Columns["colProjID"] as GridViewComboBoxColumn;
col.DataSource = dc.Proj2s.OrderBy(o => o.Code);
col.FieldName = "ProjID";
col.DisplayMember = "Code";
col.ValueMember = "ID";
col.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDown;

If the solution isn't obvious, I can prepare test project, but I have it bound to database now, so it would take some time.

I have a grid with 60,000 records and I have the filter line at the top of the grid. When a user writes to the filter line, it takes a few minutes for the grid to be filtered.

Telerik version is 2021.2.511.40.

Are there any performance improvements in newer versions? Is there a guarantee that if we update the Telerik version this problem will be resolved?

Hello!
1. How to correctly implement adding unique groups to the list and deleting non-existent ones?
The GroupSummaryEvaluate event does not occur when deleting the last entry in a group (deleting this group). That is, it is necessary for the ListBox to display the same groups as in the Grid.

lbGroups.DataSource = lstGroups.ToList

Public Class Form1
Dim lstGroups As New SortedSet(Of String)
Private Sub grdURLs2_GroupSummaryEvaluate(sender As Object, e As GroupSummaryEvaluationEventArgs) Handles grdURLs2.GroupSummaryEvaluate
        If lstGroups.Add(e.Value) Then
' code
        End If
End Sub
End Class

2. How to remove the Close button from the Search Bar?

For Each row In grdURLs2.TableElement.VisualRows
    If TypeOf row Is GridSearchRowElement Then
        Dim searchRow = TryCast(row, GridSearchRowElement)
        searchRow.SearchCellElement.CloseButton.Visibility = False
        Exit For
    End If
Next

Thank you!