Last Updated: 13 Jun 2024 14:13 by ADMIN
Created by: Zubin
Comments: 2
Category: UI for WinForms
Type: Bug Report



I added a screen with RadSpreadsheet on it. When I open that screen from the parent screen, the DPI (scale) of the whole application changes.


Please find the source in the attachment.

Last Updated: 27 May 2024 12:32 by ADMIN
This exception is a result of changes in the Current property of the IEnumerator interface. With the lastest version, if the current item is undefined it will throw an exception if we try to access it with the Current property, while in the older version, it will return null.
Last Updated: 17 Apr 2024 08:22 by ADMIN
The issue is reproducible only on Windows XP. On newer versions of windows, the images are rendered as expected.

WORKAROUND: You may try implementing custom filter that handles the CMYK scenario. How to implement custom DCTDecode filter is described in this documentation article:
Last Updated: 03 Apr 2024 15:24 by Sagar
Created by: Sagar
Comments: 4
Category: UI for WinForms
Type: Bug Report
# Vulnerability Report: Account Takeover via Email Change Functionality

## Summary:
During security testing of the email change functionality on the Telerik website, it was discovered that the application can be vulnerable to an account takeover attack. The vulnerability allows an attacker to change the email address associated with an account to their own email address, effectively taking over the victim's account.

## Vulnerability Details:
- **Functionality Description:**
  - The Telerik website provides a functionality for users to request a change in their email address.
  - This functionality consists of two sections: current email and new email.
  - The current email is not accessible from the user interface, while the new email can be inputted by the user.
  - After inputting the new email and clicking the "Change Email" button, the user's request is processed.

- **Attack Scenario:**
  1. **Attacker Inputs Their Email:** The attacker inputs their own email address in the new email section.
  2. **Intercepting the Request:** Using interception tools, the attacker intercepts the request before it is sent to the server.
  3. **Modifying the Request:** The attacker modifies the request to replace their own email address with the victim's email address in the current email section.
  4. **Consent Form Manipulation:** Additionally, the attacker can manipulate the consent form associated with the email change request to gain access to the victim's account without their consent.
  5. **Changing the Email Address:** The modified request is forwarded to the server, resulting in the victim's email address being changed to the attacker's email address.

## Impact:
- **Account Takeover:** The vulnerability allows an attacker to take over the victim's account by changing the email address associated with it.
- **Data Access:** Once the attacker gains access to the victim's account, they may have unauthorized access to sensitive data and functionalities associated with the account.

## Mitigation Recommendations:
- **Input Validation:** Implement strict input validation to ensure that only legitimate email addresses are accepted in the new email section.
- **Consent Verification:** Require additional verification steps, such as email confirmation or user authentication, before processing email change requests.
- **Session Management:** Implement session management mechanisms to detect and prevent unauthorized access to account settings and functionalities.
- **Security Awareness:** Educate users about the risks of phishing attacks and social engineering tactics used by attackers to gain unauthorized access to accounts.

## Affected URL:
- Email Change Functionality: [](

## Conclusion:
The discovered vulnerability poses a significant security risk to Telerik website users by allowing attackers to take over accounts through manipulation of the email change functionality. It is imperative for the development team to address this vulnerability promptly by implementing appropriate security controls and mitigations to safeguard user accounts from unauthorized access.

**Best Regards,**
Sagar Dhoot
Last Updated: 01 Mar 2024 13:13 by ADMIN

PerformClick method of RadButtonElement is sending next error:

System.InvalidCastException: 'Unable to cast object of type 'System.EventArgs' to type 'System.Windows.Forms.MouseEventArgs'.

Find my code below:

private void btnAddField_Click(object sender, EventArgs e)
    RadDiagramShape sourceShape = new RadDiagramShape()
        Text = "source",
        Shape = new RoundRectShape(5),
        BackColor = Color.Red

    sourceShape.Position = new Telerik.Windows.Diagrams.Core.Point(150, 100);

    sourceShape.IsSelected = true;
    RadButtonElement additionalContent = Telerik.WinControls.UI.Diagrams.Primitives.ItemInformationAdorner.GetAdditionalContent(
                                            this.radDiagram.DiagramElement.ItemInformationAdorner) as RadButtonElement;


What I want is to display the SettingsPane automatically when adding a RadDiagramShape item in a RadDiagram


Last Updated: 20 Feb 2024 12:26 by ADMIN

Hi- When I add a Rad context menu to a RadToolbarForm, the toolbar vanishes from the designer after a build.  This is new behavior because I have other context menus that I had previously added to the form.  If I drag a RadContextMenu from the toolkit, or I copy/paste an existing context menu, the toolbar disappears after a build.  I am running the latest release (2024.1.130) and toolkit config (although this also happens when running the previous Telerik release)

I tried closing the designer before the build and the toolbar still disappears.  Doing a Clean before build has no effect.  This form is inherited from a simple RadToolbar form (no controls except the toolbar).  The toolbar is still listed in the list of controls for the form

Ha!  Just found out what's happening.  It's deleting the toolbar configuration code from the designer code.  Everything below is gone.  If I add it back in, then do anything with the new context menu, like rename it, it gets removed again

            // RadToolbarFormControl1
            RadToolbarFormControl1.AutoSize = false;
            RadToolbarFormControl1.CenterItems.AddRange(new Telerik.WinControls.RadItem[] { RadLabelElement1, RadButtonElement_Task_New, RadButtonElement_Task_Edit, RadButtonElement_Task_Delete, RadCheckBoxElement_ShowCompleted });
            RadToolbarFormControl1.CenterItemsVerticalAlignment = Telerik.WinControls.UI.RadVerticalAlignment.Bottom;
            RadToolbarFormControl1.FarItems.AddRange(new Telerik.WinControls.RadItem[] { RadLabelElement_WorkHours, RadLabelElement_Work_StartDate, RadLabelElement_Work_EndDate, RadButtonElement_SelectDates, RadButtonElement_Invoices, RadButtonElement_Summary });
            RadToolbarFormControl1.NearItems.AddRange(new Telerik.WinControls.RadItem[] { RadLabelElement2, RadLabelElement_Projects, RadButtonElement_New, RadButtonElement_Edit, RadButtonElement_Delete, RadButtonElement_Refresh });
            RadToolbarFormControl1.ShowText = false;
            RadToolbarFormControl1.Size = new Size(1804, 52);


Here's my dev environment:

Microsoft Visual Studio Community 2022
Version 17.8.7
Microsoft .NET Framework
Version 4.8.09037

Installed Version: Community

ActiveReports 16
The first report writer for Microsoft .NET

ASP.NET and Web Tools   17.8.358.6298
ASP.NET and Web Tools

Azure App Service Tools v3.0.0   17.8.358.6298
Azure App Service Tools v3.0.0

C# Tools   4.8.0-7.23572.1+7b75981cf3bd520b86ec4ed00ec156c8bc48e4eb
C# components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.

Code Converter   1.0
Code Converter Extension Details

Common Azure Tools   1.10
Provides common services for use by Azure Mobile Services and Microsoft Azure Tools.

Microsoft JVM Debugger   1.0
Provides support for connecting the Visual Studio debugger to JDWP compatible Java Virtual Machines

NuGet Package Manager   6.8.1
NuGet Package Manager in Visual Studio. For more information about NuGet, visit

Progress Telerik UI for WinForms Extension   2023.3.1110.93
Progress® Telerik® UI for WinForms Extension

TypeScript Tools   17.0.20920.2001
TypeScript Tools for Microsoft Visual Studio

Visual Basic Tools   4.8.0-7.23572.1+7b75981cf3bd520b86ec4ed00ec156c8bc48e4eb
Visual Basic components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.

Visual F# Tools   17.8.0-beta.23475.2+10f956e631a1efc0f7f5e49c626c494cd32b1f50
Microsoft Visual F# Tools

Visual Studio IntelliCode   2.2
AI-assisted development for Visual Studio.


Last Updated: 16 Feb 2024 22:25 by ADMIN

I can't provide a project or even code snippets that would make sense out of context because the code base is too complex for an easy replication to be setup.

We are trying various things like calling Refresh, Update.


Hoping this is something you've encountered before and have some suggestions.

Last Updated: 16 Feb 2024 22:24 by ADMIN

C#. net core 6, winforms application, TekerikNuGet3 package source, UI.for.WinForms.AllControls.NetCore package 2022.2.622

I am trying to export selected cells from a RadGridView as a csv file.

When using "var exporter = new ExportToCSV(Dgv)" then "exporter.RunExport(fileName);" writes the csv file correctly. It exports every cell.

It doesn't support exporting selections so I wrote a function to do this . The one below is what I used in my project to test what I was doing. It initially writes the csv to a worksheet and wrote that using formatprovider to file, then I just created a stringbuilder adding quotes and appended that to the file afterwards.

Writing the worksheet, the csv values haven't been quoted, plus number fields have had leading zeros removed which proves to be a problem when telephone numbers are stored in a field.

So I googled and found the Settings property which is there to set csv options. But they are private, not public therefore I can't set up the csv propertly.

private void radButton1_Click(object sender, EventArgs e)

    var workbook = new Workbook();
    var worksheet = workbook.Worksheets.Add();

    var rowIndex = 0;
    var columnIndex = -1;
    var sb = new StringBuilder();
    var prevColumnIndex = -1;

    // ForEach cell are accessed vertically then horizontally.
    foreach (var cell in Dgv.SelectedCells)
      // Cell is included in selection even if it's invisible
      // so check visibility and ignore if it isnt
      if (!cell.ColumnInfo.IsVisible) continue;

      // At bottom of column, rownum will change. Watch for this
      // and reset x and y values
      var rowNum = cell.RowInfo.Index;
      if (rowNum != prevColumnIndex)
        prevColumnIndex = rowNum;
        rowIndex = 0;
      else if (!string.IsNullOrEmpty(sb.ToString()))

      var value = cell.Value;
      worksheet.Cells[columnIndex, rowIndex++ ].SetValue(value.ToString());

    var fileName = @"C:\temp\SampleFile.csv";

    IWorkbookFormatProvider formatProvider = new CsvFormatProvider();
    using var output = new FileStream(fileName, FileMode.Create);
    formatProvider.Export(workbook, output);

    // Write contents of sb to the file for comparison sake
    File.AppendAllText(fileName, sb.ToString());


Last Updated: 16 Feb 2024 22:22 by ADMIN

I just upgraded to the latest version of Telerik products and facing the issues described below.

When dragging and drop Telerik UI objects from the toolbar on a form, the dialog box below is displayed with question but there is no button to click to answer the question and I don't where to stop it.

See screenshot attached.

Last Updated: 16 Feb 2024 22:20 by ADMIN
Created by: Ian
Comments: 2
Category: ChartView
Type: Feature Request
Some other charting frameworks support ‘dynamic’ graphs/diagrams, where the graph shows nodes and links, and the user can drag the nodes around the page, and the other nodes are pulled around it. This is a great way to visualise and explore this kind of node+link data. Its also a great way to sell and app, as it looks cool.
Last Updated: 16 Feb 2024 22:19 by ADMIN
Created by: Haithem
Comments: 2
Category: PdfViewer
Type: Bug Report



I am have a problem with pdf wiewer when the PDF file contains an images , it is slow in movement and it is difficult to navigate between pages. Is it possible to fix this problem 



Last Updated: 16 Feb 2024 22:18 by ADMIN

Hi All,

Note:- I am using Bound RadTreeview. Bound with DataSource.

1 Take RadTreeview

2 Add Few nodes Like:

    ......Node A

    ......Node B

    ......Node C

    ............Node D

    ............Node E

3 Now Drag Node B and Drop it in Node C (As Node C's Child)

4 It throw Exception Error Msg  "Collection was modified; enumeration operation may not execute."

5  Now Try to Drag Node E and Drop it in Node B, again same error occurs

6 Full error screen i attached here.

Please reply as soon as possible.


Last Updated: 16 Feb 2024 20:34 by ADMIN

Hello Guys,


Good Evening , As per your suggestions i make my custom treeview node with LiteVisualElements .

In That Node i have taken one StackLayoutElement and RoundRectShape assigned to it but still panel shows corners instead of round edges,

i tried with different properties and styles but not get succeed , so please help me out.

here i have attached image of my node and "stackLayoutElement" code too.

spnlControls = new StackLayoutElement();
            spnlControls.Orientation = Orientation.Horizontal;
            spnlControls.NotifyParentOnMouseInput = true;
            spnlControls.DrawFill = true;
            spnlControls.DrawBorder = true;
            spnlControls.Shape = new RoundRectShape(4);
            spnlControls.BackColor = Color.Transparent;
            spnlControls.BackColor2 = Color.Transparent;
            spnlControls.BackColor3 = Color.Transparent;
            spnlControls.BackColor4 = Color.Transparent;
            spnlControls.BorderGradientStyle = GradientStyles.Solid;
Last Updated: 16 Feb 2024 20:33 by ADMIN
Created by: James
Comments: 2
Category: UI for WinForms
Type: Bug Report

Zooming in will throw an Exception that crashes the program.

The ZoomLevel needed to cause the exception is dependent on the area of the RadMap selected.

Provider: BingRestMapProvider

ImagerySet AerialWithLabelsOnDemand



Zooming in over Antarctica, Exception thrown zooming in at MapElement.ZoomLevel 14.


Zooming in over Australia, Exception thrown zooming in at MapElement.ZoomLevel 21.


Last Updated: 16 Feb 2024 20:32 by ADMIN
Created by: Kaan
Comments: 2
Category: UI for WinForms
Type: Feature Request


I want to hide some columns of the table I received from Excel on RadGridView.

Last Updated: 16 Feb 2024 20:31 by ADMIN
Created by: Larry
Comments: 2
Category: RichTextEditor
Type: Bug Report
There appears to be an issue when adding Comments that overlap each other. I will attach a video to my next reply that shows how to replicate the issue.
Last Updated: 16 Feb 2024 20:30 by ADMIN
Fatching data from sql database in gridViewCommboBoxColumn select the value then retrieve data other column in the same Rows windows application in
Last Updated: 16 Feb 2024 20:28 by ADMIN
The filter UI controls in ASP.NET Core and MVC are really nice, see filter. Can you include the same controls and UI be included in Winforms and WPF?
Last Updated: 16 Feb 2024 20:26 by ADMIN
Created by: Mario
Comments: 4
Category: UI for WinForms
Type: Feature Request

Hi everybody


I m try use the class CustomDragandDrop on radtreeview but i have a issue, 

if i use the next example, i dont have any problem:


   protected void BindRadTreeView()
            DataTable dt = new DataTable();
            dt.Columns.Add("Id", typeof(string));
            dt.Columns.Add("Title", typeof(string));
            dt.Columns.Add("ParentId", typeof(string));

            string parentId = string.Empty;
            string childId = string.Empty;
            for (int i = 0; i < 2; i++)
                parentId = Guid.NewGuid().ToString();
                dt.Rows.Add(parentId, "Node" + i, null);
                for (int j = 0; j < 5; j++)
                    childId = Guid.NewGuid().ToString();
                    dt.Rows.Add(childId, "SubNode" + i + "." + j, parentId);

            this.radTreeView1.ChildMember = "Id";
            this.radTreeView1.ParentMember = "ParentId";
            this.radTreeView1.DisplayMember = "Title";
            this.radTreeView1.DataSource = dt;



i can drag and drop correctly


but the problem is when i binding the Radtreeview



    protected void llenatreeview1() {

            dtTablas = dat.consultaBD();

            DataTable dt = new DataTable();
            dtCopi.Columns.Add("Id", typeof(string));
            dtCopi.Columns.Add("Title", typeof(string));
            dtCopi.Columns.Add("ParentId", typeof(string));

            string parentId = string.Empty;
            string Id = string.Empty;
            string title = string.Empty;
            foreach (DataRow row in dtTablas.Rows)
                parentId = row["ParentId"].ToString();     

                Id = row["Id"].ToString();
                title = row["Title"].ToString();

                if (parentId == "")
                    dt.Rows.Add(Id, title, null);
                    dt.Rows.Add(Id, title, parentId);

            radTreeView2.ChildMember = "Id";
            radTreeView2.ParentMember = "ParentId";
            radTreeView2.DisplayMember = "Title";
            radTreeView2.DataSource = dt;

first is freeze and then appears the error.

when i drag and drop appears then next error:



what am I doing wrong please your help. thanks
Last Updated: 16 Feb 2024 20:24 by ADMIN
Created by: Ian
Comments: 2
Category: UI for WinForms
Type: Feature Request

GridView has a default text alignment for new columns as 'MiddleCenter'.

Default alignment for new GridViewDataRowInfo is 'left'.

Please can these be the same ?

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