ExceptionHandler.GetUnknownExceptionMessage(Exception) Method

Enables you to handle server-side errors of non-standard types.

Namespace: DevExpress.XtraReports.Web.ClientControls

Assembly: DevExpress.XtraReports.v19.1.Web.dll

NuGet Package: DevExpress.Web.Reporting.Common

Declaration

C#

public virtual string GetUnknownExceptionMessage(
    Exception ex
)

VB.NET

Public Overridable Function GetUnknownExceptionMessage(
    ex As Exception
) As String

Parameters

Name	Type	Description
ex	Exception	An exception that occurs on the server side.

Returns

Type	Description
String	A string to show in a browser when an error occurs.

Remarks

Web Reporting Controls display the standard “Internal Server Error” message in a browser for unknown errors (for instance, when you try to open a broken report layout or a file that does not exist).

The GetUnknownExceptionMessage method is called whenever such an error occurs. You can override this method and return a string with error details or meaningful message.

The following classes are inherited from the base ExceptionHandler class and provide this method:

• ReportDesignerExceptionHandler
• WebDocumentViewerExceptionHandler
• QueryBuilderExceptionHandler

The code snippet below demonstrates how to create a descendant from the ReportDesignerExceptionHandler class and override the GetExceptionMessage method to return an actual exception message.

C#

using System;
using DevExpress.XtraReports.Web.ReportDesigner.Services;

public class CustomReportDesignerExceptionHandler : ReportDesignerExceptionHandler {
    public override string GetUnknownExceptionMessage(Exception  ex) {
        return ex.Message;
    }
}

VB.NET

Imports System
Imports DevExpress.XtraReports.Web.ReportDesigner.Services

Public Class CustomReportDesignerExceptionHandler
    Inherits ReportDesignerExceptionHandler

    Public Overrides Function GetUnknownExceptionMessage(ByVal ex As Exception) As String
        Return ex.Message
    End Function
End Class

To register the implemented exception handler, use the static DefaultReportDesignerContainer.Register method at the application’s startup as shown below:

C#

void Application_Start(object sender, EventArgs e) {
    // ...
    DevExpress.XtraReports.Web.ReportDesigner.DefaultReportDesignerContainer.
        Register<IReportDesignerExceptionHandler, CustomReportDesignerExceptionHandler>();
}

VB.NET

Private Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
    ' ...
    DevExpress.XtraReports.Web.ReportDesigner.DefaultReportDesignerContainer.
        Register(Of IReportDesignerExceptionHandler, CustomReportDesignerExceptionHandler)()
End Sub

See the following topics for more information:

• Handle Server-Side Errors in the Document Viewer (ASP.NET WebForms)
• Handle Server-Side Errors in the Document Viewer (ASP.NET MVC)
• Handle Server-Side Errors in the Document Viewer (ASP.NET Core)