CustomWebDocumentViewerExceptionHandler.cs

using System;
using System.IO;
using System.ServiceModel;
using DevExpress.XtraReports.Web.WebDocumentViewer;

namespace DXWebApplication1.Services {
    public class CustomWebDocumentViewerExceptionHandler : WebDocumentViewerExceptionHandler {
        public override string GetDocumentCreationExceptionMessage(DocumentCreationException ex) {
            var customExpressionException = ex.GetBaseException() as CustomInvalidRangeException;
            if (customExpressionException != null) {
                return customExpressionException.DetailedMessage;
            } else {
                return base.GetDocumentCreationExceptionMessage(ex);
            };
        }

        public override string GetFaultExceptionMessage(FaultException faultException) {
            return "FaultException occurred: " + faultException.Message + ".";
        }

        public override string GetUnknownExceptionMessage(Exception ex) {
            if (ex is FileNotFoundException) {
#if DEBUG
                return "Debug mode. " + ex.Message + ".";
#else
                return "File is not found.";
#endif
            }
            return ex.GetType().Name + " occurred. See the log file for more details.";
        }
    }
}