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How to Use ComponentResourceManager to Localize Forms with Telerik WinForms Controls

Updated on Sep 10, 2026

Environment

Product Version	Product	Author
2026.3.812	UI for WinForms	Desislava Yordanova

In standard Windows Forms development, setting a Form's Localizable property to true instructs Visual Studio to generate culture-specific resource (.resx) files and serialize control properties through System.ComponentModel.ComponentResourceManager.

When working with Telerik UI for WinForms, developers often need to understand the following:

How ComponentResourceManager interacts with Telerik controls.
How .resx resource localization differs from Telerik LocalizationProvider classes.
How to dynamically change languages at runtime by using ComponentResourceManager.ApplyResources.

ComponentResourceManager vs. LocalizationProvider

It is important to distinguish between two distinct localization layers:

ComponentResourceManager (.resx files): Localizes form-level and control-level properties configured in the Visual Studio designer (such as Text, Size, Location, and Font). All Telerik controls inherit from System.Windows.Forms.Control, meaning design-time property values are serialized to .resx files and applied when the form is initialized.
Telerik LocalizationProvider: Localizes built-in internal strings that are part of the controls' internal templates and dialogs (such as RadGridView filtering operator menus, the Column Chooser text, conditional formatting dialogs, and RadScheduler dialog labels). These internal strings are not stored in form .resx files and must be localized using Telerik localization providers (for example, RadGridLocalizationProvider).

Solution

Localizing Forms at Design Time

To localize a form at design time using standard .resx resources:

Open your form in the Visual Studio designer.
Select the Form and set its Localizable property to true in the Properties window.
Select the desired language in the Language property (for example, German).
Update the properties of your Telerik controls (for example, set the Text of a RadButton or RadLabel to German text, or adjust column header texts).
Visual Studio creates a dedicated resource file (such as MyForm.de.resx) and generates code in InitializeComponent() using ComponentResourceManager.ApplyResources() to apply the localized values based on Thread.CurrentThread.CurrentUICulture.

Runtime Language Switching

When an application changes culture at runtime without closing and recreating the form, you can re-apply resources by calling resources.ApplyResources() on the form and its controls.

Because Telerik controls host internal visual elements (such as RadMenuItem, GridViewDataColumn, and RadTreeNode) that are components or lightweight elements rather than child System.Windows.Forms.Control instances, a standard recursive control loop must also iterate over these specific Telerik element collections.

The following example demonstrates how to switch culture dynamically and update Telerik controls and columns:

using System;
using System.ComponentModel;
using System.Globalization;
using System.Threading;
using System.Windows.Forms;
using Telerik.WinControls.UI;

public partial class RadForm1 : RadForm
{
    public RadForm1()
    {
        InitializeComponent();
    }

    private void ApplyCulture(CultureInfo culture)
    {
        // 1. Update the UI culture of the current thread
        Thread.CurrentThread.CurrentUICulture = culture;
        Thread.CurrentThread.CurrentCulture = culture;

        // 2. Initialize the ComponentResourceManager for this form
        ComponentResourceManager resources = new ComponentResourceManager(this.GetType());

        // 3. Suspend layout and apply resources to the form and controls
        this.SuspendLayout();
        ApplyResourcesToControl(resources, this);
        this.ResumeLayout(true);
    }

    private void ApplyResourcesToControl(ComponentResourceManager resources, Control control)
    {
        // Apply resources to the control itself
        string resourceKey = control is Form ? "$this" : control.Name;
        resources.ApplyResources(control, resourceKey);

        // Apply resources to Telerik-specific items
        if (control is RadGridView grid)
        {
            foreach (GridViewColumn column in grid.Columns)
            {
                resources.ApplyResources(column, column.Name);
            }
        }
        else if (control is RadMenu menu)
        {
            foreach (RadMenuItemBase item in menu.Items)
            {
                ApplyResourcesToMenuItem(resources, item);
            }
        }

        // Recursively apply to child controls
        foreach (Control child in control.Controls)
        {
            ApplyResourcesToControl(resources, child);
        }
    }

    private void ApplyResourcesToMenuItem(ComponentResourceManager resources, RadMenuItemBase menuItem)
    {
        resources.ApplyResources(menuItem, menuItem.Name);

        if (menuItem is RadMenuItem parentItem)
        {
            foreach (RadMenuItemBase child in parentItem.Items)
            {
                ApplyResourcesToMenuItem(resources, child);
            }
        }
    }
}