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1 answer
44 views

¡Hi everyone! I have this issue loading a pdf with the RadPdfViewer.
On the RadPdfViewer DataError event i got an InvalidOperationException with only the "Stack empty" messsage,

 

This is the stacktrace of the exception thown by the PdfExceptionEventArgs

   at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
   at System.Collections.Generic.Stack`1.Pop()
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.DocumentModel.PdfContext.RestoreGraphicState()
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfReader.Parsers.ContentStreamParser.InvokeGeneralGraphicsStateOperator(String op, Object[] pars)
   at Telerik.Windows.Pdf.Documents.Fixed.FormatProviders.Old.Pdf.PdfReader.Parsers.ContentStreamParser.InvokeOperator(String op, Object[] pars)

Can you please tell me what could be the possible reason of this issue ? Thanks

PS. The file is on the zip attached

Nadya | Tech Support Engineer
Telerik team
 answered on 05 Feb 2025
1 answer
37 views

Regarding the RadMaskedEditBox using the provided Email MaskType:

The error validation icon displays when there is an error, but it doesn't prevent the user from leaving the field. 

How can I prevent the user from leaving the field with this MaskType?

 

 

Dinko | Tech Support Engineer
Telerik team
 answered on 05 Feb 2025
1 answer
58 views

Hey there!

I've been converting several programs that use 'RadGridView' to'VirtualMode' lately, and yesterday I encountered an issue with one that has template relations. I tried a few approaches, but I can't seem to make it work with the same logic I was using before. However, I did manage to get it working with the 'RowSourceNeeded' event, but it requires me to iterate over the same records more times than I'd like.

Is there another way to achieve this, or is this the only available solution?

 

JP

Nadya | Tech Support Engineer
Telerik team
 answered on 31 Jan 2025
1 answer
53 views

Hi,

I would like to use a set of radio buttons and have them render using the 'button' appearance (i.e. instead of the default circular checkbox appearance).  For a normal Winforms System.Windows.Forms.RadioButton control, this is accomplished by setting the RadioButton.Appearance property to 'Button'.  However, the Telerik RadRadioButton control does not have that property.  How can this be accomplished with the Telerik radio button control?

Thanks!

--Darren

 

Dinko | Tech Support Engineer
Telerik team
 answered on 28 Jan 2025
1 answer
46 views

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.


Nadya | Tech Support Engineer
Telerik team
 answered on 24 Jan 2025
2 answers
58 views
I've tried implement custom filter as per  Permanent editor in a filter cell - Telerik UI for WinForms instruction
but when I run that project drop down list looks too small to hold its content. Please look at attached screenshot. 

Could you advise me how to properly calculate size of dropdown, or in other way make it fit its content. The only way I found is to set 
 this.dropDown.MinSize = new Size(150, 30); 

inside CreateChildElements method. But I'm not sure this is the best way to fix this issue. Could you please advise me how to handle those kinds of size issues?

Ruslan
Top achievements
Rank 1
Iron
 answered on 23 Jan 2025
1 answer
80 views

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

Nadya | Tech Support Engineer
Telerik team
 answered on 23 Jan 2025
1 answer
100 views

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?

Nadya | Tech Support Engineer
Telerik team
 answered on 20 Jan 2025
1 answer
59 views

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

Nadya | Tech Support Engineer
Telerik team
 answered on 20 Jan 2025
1 answer
51 views

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

 

Dinko | Tech Support Engineer
Telerik team
 answered on 17 Jan 2025
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