Fixed ObjectDisposedException on MSBuildBasedProject in OptionPanels.ApplicationSettings.<LoadPanelContents>b__1:

- close project options view when the project is removed from the solution
- use an event on MSBuildBasedProject to detect a changed tools version, instead of querying it whenever the option page becomes visible

src/Main/Base/Project/Src/Gui/Dialogs/OptionPanels/ProjectOptions/ApplicationSettings.cs

@@ -75,11 +75,10 @@ namespace ICSharpCode.SharpDevelop.Gui.OptionPanels
 			applicationManifestComboBox.TextChanged += delegate { helper.IsDirty = true; };
 			
 			// embedding manifests requires the project to target MSBuild 3.5 or higher
+			project_MinimumSolutionVersionChanged(null, null);
 			// re-evaluate if the project has the minimum version whenever this options page gets visible
 			// because the "convert project" button on the compiling tab page might have updated the MSBuild version.
-			applicationManifestComboBox.VisibleChanged += delegate {
+			project.MinimumSolutionVersionChanged += project_MinimumSolutionVersionChanged;
-				applicationManifestComboBox.Enabled = project.MinimumSolutionVersion >= Solution.SolutionVersionVS2008;
-			};
 			
 			Get<TextBox>("projectFolder").Text = project.Directory;
 			Get<TextBox>("projectFile").Text = Path.GetFileName(project.FileName);
@@ -93,6 +92,18 @@ namespace ICSharpCode.SharpDevelop.Gui.OptionPanels
 			helper.AddConfigurationSelector(this);
 		}
 		
+		void project_MinimumSolutionVersionChanged(object sender, EventArgs e)
+		{
+			// embedding manifests requires the project to target MSBuild 3.5 or higher
+			applicationManifestComboBox.Enabled = project.MinimumSolutionVersion >= Solution.SolutionVersionVS2008;
+		}
+		
+		protected override void Dispose(bool disposing)
+		{
+			project.MinimumSolutionVersionChanged -= project_MinimumSolutionVersionChanged;
+			base.Dispose(disposing);
+		}
+		
 		void ApplicationManifestComboBox_SelectedIndexChanged(object sender, EventArgs e)
 		{
 			if (applicationManifestComboBox.SelectedIndex == applicationManifestComboBox.Items.Count - 2) {

src/Main/Base/Project/Src/Gui/Dialogs/ProjectOptionsView.cs

@@ -39,6 +39,14 @@ namespace ICSharpCode.SharpDevelop.Project.Dialogs
 			
 			tabControl.IsDirtyChanged += delegate { RaiseIsDirtyChanged(); };
 			tabControl.AddOptionPanels(node.BuildChildItems<IOptionPanelDescriptor>(project));
+			
+			ProjectService.ProjectRemoved += ProjectService_ProjectRemoved;
+		}
+		
+		void ProjectService_ProjectRemoved(object sender, ProjectEventArgs e)
+		{
+			if (e.Project == project && this.WorkbenchWindow != null)
+				WorkbenchWindow.CloseWindow(true);
 		}
 		
 		public override bool IsDirty {
@@ -67,6 +75,7 @@ namespace ICSharpCode.SharpDevelop.Project.Dialogs
 		
 		public override void Dispose()
 		{
+			ProjectService.ProjectRemoved -= ProjectService_ProjectRemoved;
 			foreach (IDisposable op in tabControl.OptionPanels.OfType<IDisposable>()) {
 				op.Dispose();
 			}

src/Main/Base/Project/Src/Project/MSBuildBasedProject.cs

@@ -114,6 +114,8 @@ namespace ICSharpCode.SharpDevelop.Project
 			}
 		}
 		
+		public event EventHandler MinimumSolutionVersionChanged;
+		
 		protected void SetToolsVersion(string newToolsVersion)
 		{
 			PerformUpdateOnProjectFile(
@@ -121,6 +123,8 @@ namespace ICSharpCode.SharpDevelop.Project
 					projectFile.ToolsVersion = newToolsVersion;
 					userProjectFile.ToolsVersion = newToolsVersion;
 				});
+			if (MinimumSolutionVersionChanged != null)
+				MinimumSolutionVersionChanged(this, EventArgs.Empty);
 		}
 		
 		public void PerformUpdateOnProjectFile(Action action)

src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs

@@ -628,6 +628,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			if (project != null) {
 				OpenSolution.RemoveProjectConfigurations(project.IdGuid);
 				ParserService.RemoveProjectContentForRemovedProject(project);
+				OnProjectRemoved(new ProjectEventArgs(project));
 				project.Dispose();
 			}
 			if (folder is ISolutionFolderContainer) {
@@ -661,6 +662,12 @@ namespace ICSharpCode.SharpDevelop.Project
 				ProjectAdded(null, e);
 			}
 		}
+		static void OnProjectRemoved(ProjectEventArgs e)
+		{
+			if (ProjectRemoved != null) {
+				ProjectRemoved(null, e);
+			}
+		}
 		internal static void OnProjectCreated(ProjectEventArgs e)
 		{
 			if (ProjectCreated != null) {
@@ -682,6 +689,15 @@ namespace ICSharpCode.SharpDevelop.Project
 		/// Is raised when a new or existing project is added to the solution.
 		/// </summary>
 		public static event ProjectEventHandler ProjectAdded;
+		/// <summary>
+		/// Is raised when a project is removed from the solution.
+		/// </summary>
+		public static event ProjectEventHandler ProjectRemoved;
+		
+		/// <summary>
+		/// Is raised when a solution folder is removed from the solution.
+		/// This might remove multiple projects from the solution.
+		/// </summary>
 		public static event SolutionFolderEventHandler SolutionFolderRemoved;
 		
 		public static event EventHandler<BuildEventArgs> BuildStarted;