[Solved] Issues with Search Feature in WPF Telerik Report Viewer

[John]

Hi,

We are currently implementing the Telerik Report Viewer in a WPF application using C#. However, clicking the search button triggers an error.

To resolve this, we attempted setting searchMetadataOnDemand = true, but it caused UI rendering issues across the entire application. We have attached our source code for your reference. Could you please guide us on the correct way to implement the search feature without disrupting the UI?

[Petar]

Hi John,

Thank you for sharing the code snippet of your viewer logic.

First, I would like to clarify that SearchMetadataOnDemand is not required to enable search functionality in the WPF Report Viewer. Search is enabled by default, even when this property is set to false. When SearchMetadataOnDemand is set to true, the viewer intentionally defers generating the report's search metadata until a search operation is initiated. While this can improve the initial loading time of larger reports, it also requires the report to be processed again when the user performs a search. If this behavior is not needed in your scenario, I would recommend removing this setting and allowing the viewer to use its default behavior.

With that said, I attempted to reproduce the issue locally by adding logic similar to the code you shared, but I was unable to observe the same behavior. For reference, I have attached the sample project that I used during testing. Could you please review it and let me know whether the issue is reproducible on your end?

Additionally, it would be very helpful if you could let me know which version of Telerik Reporting your application is currently using, as well as the exact exception that occurs when the Search button is clicked.

To help us investigate further, I would recommend enabling a trace listener in your application and sharing the generated log file, as it can be particularly helpful if the issue is caused by an exception being thrown internally by the viewer. For more information on how to enable trace listeners, please refer to the following articles:

• For .NET: Troubleshooting Reporting Implementation in ASP.NET Core Application
• For .NET Framework: How to: Create and Initialize Trace Listeners

Ideally, if possible, it would be very helpful if you could modify the attached sample project until the issue becomes reproducible and then send it back to us for investigation. However, if it is possible at the moment, the log file should suffice for now.

Thank you, and I am looking forward to your reply!

Regards,
Petar
Progress Telerik

[John]

Hi,

Thanks for the reply.

The Telerik Reporting version we are using is 18.0.24.305. As suggested, we have attached the log file with this reply.

The main issue we would like to understand is why the Telerik Report Viewer theme is affecting the overall application UI when we click the Search button.

I have added the following code to apply the theme to the Telerik Report Viewer:

static readonly string[] dictionaries = new[]
                      {
                "/Telerik.ReportViewer.Wpf.Themes;component/Themes/{0}/System.Windows.xaml",
                "/Telerik.ReportViewer.Wpf.Themes;component/Themes/{0}/Telerik.Windows.Controls.xaml",
                "/Telerik.ReportViewer.Wpf.Themes;component/Themes/{0}/Telerik.Windows.Controls.Input.xaml",
                "/Telerik.ReportViewer.Wpf.Themes;component/Themes/{0}/Telerik.Windows.Controls.Navigation.xaml",
                "/Telerik.ReportViewer.Wpf.Themes;component/Themes/{0}/Telerik.ReportViewer.Wpf.xaml"
            }; private static void ApplyThemeToReportViewer(FrameworkElement element,string theme)
        {
            foreach (string dictionary in dictionaries)
            {
                string uri = string.Format(dictionary, theme);

                bool alreadyExists =
                    element.Resources.MergedDictionaries.Any(d =>
                        d.Source != null &&
                        d.Source.OriginalString == uri);

                if (!alreadyExists)
                {
                    element.Resources.MergedDictionaries.Add(
                        new ResourceDictionary()
                        {
                            Source = new Uri(
                                uri,
                                UriKind.RelativeOrAbsolute)
                        });
                }
            }

            Windows11ThemeSizeHelper.Helper.IsInCompactMode = false;

            Windows11Palette.LoadPreset(
                Windows11Palette.ColorVariation.System);
        }

[Petar]

Hi John,

The error shown in the screenshot is consistent with a known WPF Report Viewer resource-scope configuration issue; a similar case is described in the forum thread GlyphSearchStop.

To provide some additional context, the Search dialog is created as a separate WPF window, which is why resources merged directly into ReportViewer.Resources are not available to it. This also explains why the main viewer can render correctly while the Search dialog fails to resolve GlyphSearchStop.

In the original code snippet for ApplyThemeToReportViewer, I had noticed the resources were normally merged at the application level:

        // R: T391849, 2026-05-21
        private static void ApplyThemeToReportViewer(FrameworkElement element,string theme)
        {
            // R: T391849, 2026-08-05
            ResourceDictionary targetResources = Application.Current?.Resources ?? element.Resources;
            foreach (string dictionary in dictionaries)
            {
                string uri = string.Format(dictionary, theme);

                bool alreadyExists =
                    targetResources.MergedDictionaries.Any(d =>
                        d.Source != null &&
                        d.Source.OriginalString == uri);

                if (!alreadyExists)
                {
                    targetResources.MergedDictionaries.Add(
                        new ResourceDictionary()
                        {
                            Source = new Uri(
                                uri,
                                UriKind.RelativeOrAbsolute)
                        });
                }
            }

            Windows11ThemeSizeHelper.Helper.IsInCompactMode = false;

            Windows11Palette.LoadPreset(
                Windows11Palette.ColorVariation.System);
        }
    }

In the latest code snippet, however, the resources are merged directly into element.Resources.

Could you confirm whether the error occurred before this change, and whether there was a specific reason for moving the resources from Application.Current.Resources to the viewer’s resources? As a scoped alternative, the dictionaries can also be merged into the hosting window’s resources.

[John]

Currently, the resources are merged directly into element.Resources, which resulted in an error related to GlyphSearchStop. To resolve this issue, we tried replacing element.Resources with Application.Current.Resources and merging the resources into the viewer’s resources instead.

When using Application.Current.Resources, the GlyphSearchStop issue is resolved, and the search popup is displayed correctly in the Telerik ReportViewer.

However, this approach is causing a theme-related issue, as it changes the UI theme of the entire application.

We have attached a ResourceDictionary file. Could you please review it and let us know whether it can help us resolve the theme issue while keeping the Telerik resources scoped only to the ReportViewer?

[Petar]

Hi John,

Thank you for the clarification.

Indeed, merging the resources at the application level can affect the entire application, while merging them only into the ReportViewer may cause the GlyphSearchStop error because the Search dialog uses a separate window.

As a potential solution, have you considered merging the Report Viewer resources into the hosting window’s resources instead? For example:

ApplyThemeToReportViewer(this, "Windows11");

where this is the window hosting the report viewer.

That said, the drawback is that the resources may also affect other compatible controls hosted in the same window.