Fix null reference exception when opening a WiX dialog in the designer.

src/AddIns/DisplayBindings/FormsDesigner/Project/Src/DesignerViewContent.cs

@@ -12,11 +12,11 @@ using System.IO;
 using System.Linq;
 using System.Text;
 using System.Windows.Forms;
-
 using ICSharpCode.Core;
 using ICSharpCode.FormsDesigner.Services;
 using ICSharpCode.FormsDesigner.UndoRedo;
 using ICSharpCode.SharpDevelop;
+using ICSharpCode.SharpDevelop.Dom;
 using ICSharpCode.SharpDevelop.Editor;
 using ICSharpCode.SharpDevelop.Gui;
 
@@ -277,7 +277,7 @@ namespace ICSharpCode.FormsDesigner
 			serviceContainer.AddService(typeof(DesignerOptionService), new SharpDevelopDesignerOptionService());
 			serviceContainer.AddService(typeof(ITypeDiscoveryService), new TypeDiscoveryService());
 			serviceContainer.AddService(typeof(MemberRelationshipService), new DefaultMemberRelationshipService());
-			serviceContainer.AddService(typeof(ProjectResourceService), new ProjectResourceService(ParserService.GetParseInformation(this.DesignerCodeFile.FileName).CompilationUnit.ProjectContent));
+			serviceContainer.AddService(typeof(ProjectResourceService), CreateProjectResourceService());
 			
 			// Provide the ImageResourceEditor for all Image and Icon properties
 			this.addedTypeDescriptionProviders.Add(typeof(Image), TypeDescriptor.AddAttributes(typeof(Image), new EditorAttribute(typeof(ImageResourceEditor), typeof(System.Drawing.Design.UITypeEditor))));
@@ -329,6 +329,21 @@ namespace ICSharpCode.FormsDesigner
 			LoggingService.Info("Form Designer: END INITIALIZE");
 		}
 		
+		ProjectResourceService CreateProjectResourceService()
+		{
+			IProjectContent projectContent = GetProjectContentForFile();
+			return new ProjectResourceService(projectContent);
+		}
+		
+		IProjectContent GetProjectContentForFile()
+		{
+			ParseInformation parseInfo = ParserService.GetParseInformation(this.DesignerCodeFile.FileName);
+			if (parseInfo != null) {
+				return parseInfo.CompilationUnit.ProjectContent;
+			}
+			return DefaultProjectContent.DummyProjectContent;
+		}
+		
 		bool hasUnmergedChanges;
 		
 		void MakeDirty()