Fix #2550: Menu "Save Code" enable issue on changing C# version

ILSpy/MainWindow.xaml.cs

@@ -824,7 +824,6 @@ namespace ICSharpCode.ILSpy
 
 		void filterSettings_PropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
-			RefreshTreeView();
 			RefreshTreeViewFilter();
 			if (e.PropertyName == "Language" || e.PropertyName == "LanguageVersion")
 			{
@@ -1173,11 +1172,6 @@ namespace ICSharpCode.ILSpy
 		}
 
 		void RefreshCommandExecuted(object sender, ExecutedRoutedEventArgs e)
-		{
-			RefreshTreeView();
-		}
-
-		void RefreshTreeView()
 		{
 			try
 			{

ILSpy/TreeNodes/AssemblyTreeNode.cs

@@ -200,7 +200,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		void LoadChildrenForPEFile(PEFile module)
 		{
-			typeSystem = LoadedAssembly.GetTypeSystemOrNull(DecompilerTypeSystem.GetOptions(new DecompilationOptions().DecompilerSettings));
+			typeSystem = LoadedAssembly.GetTypeSystemOrNull();
 			var assembly = (MetadataModule)typeSystem.MainModule;
 			this.Children.Add(new Metadata.MetadataTreeNode(module, this));
 			Decompiler.DebugInfo.IDebugInfoProvider debugInfo = LoadedAssembly.GetDebugInfoOrNull();

ILSpy/TreeNodes/EventTreeNode.cs

@@ -17,6 +17,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Reflection.Metadata;
 using System.Windows.Media;
 
 using ICSharpCode.Decompiler;
@@ -45,14 +46,21 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public IEvent EventDefinition { get; }
 
-		public override object Text => GetText(EventDefinition, this.Language) + EventDefinition.MetadataToken.ToSuffixString();
+		public override object Text => GetText(GetEventDefinition(), this.Language) + EventDefinition.MetadataToken.ToSuffixString();
+
+		private IEvent GetEventDefinition()
+		{
+			return ((MetadataModule)EventDefinition.ParentModule.PEFile
+				?.GetTypeSystemWithCurrentOptionsOrNull()
+				?.MainModule)?.GetDefinition((EventDefinitionHandle)EventDefinition.MetadataToken) ?? EventDefinition;
+		}
 
 		public static object GetText(IEvent ev, Language language)
 		{
 			return language.EventToString(ev, false, false, false);
 		}
 
-		public override object Icon => GetIcon(EventDefinition);
+		public override object Icon => GetIcon(GetEventDefinition());
 
 		public static ImageSource GetIcon(IEvent @event)
 		{
@@ -76,7 +84,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public override bool IsPublicAPI {
 			get {
-				switch (EventDefinition.Accessibility)
+				switch (GetEventDefinition().Accessibility)
 				{
 					case Accessibility.Public:
 					case Accessibility.ProtectedOrInternal:

ILSpy/TreeNodes/FieldTreeNode.cs

@@ -17,6 +17,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Reflection.Metadata;
 using System.Windows.Media;
 
 using ICSharpCode.Decompiler;
@@ -37,14 +38,21 @@ namespace ICSharpCode.ILSpy.TreeNodes
 			this.FieldDefinition = field ?? throw new ArgumentNullException(nameof(field));
 		}
 
-		public override object Text => GetText(FieldDefinition, Language) + FieldDefinition.MetadataToken.ToSuffixString();
+		public override object Text => GetText(GetFieldDefinition(), Language) + FieldDefinition.MetadataToken.ToSuffixString();
+
+		private IField GetFieldDefinition()
+		{
+			return ((MetadataModule)FieldDefinition.ParentModule.PEFile
+				?.GetTypeSystemWithCurrentOptionsOrNull()
+				?.MainModule)?.GetDefinition((FieldDefinitionHandle)FieldDefinition.MetadataToken) ?? FieldDefinition;
+		}
 
 		public static object GetText(IField field, Language language)
 		{
 			return language.FieldToString(field, includeDeclaringTypeName: false, includeNamespace: false, includeNamespaceOfDeclaringTypeName: false);
 		}
 
-		public override object Icon => GetIcon(FieldDefinition);
+		public override object Icon => GetIcon(GetFieldDefinition());
 
 		public static ImageSource GetIcon(IField field)
 		{
@@ -77,7 +85,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public override bool IsPublicAPI {
 			get {
-				switch (FieldDefinition.Accessibility)
+				switch (GetFieldDefinition().Accessibility)
 				{
 					case Accessibility.Public:
 					case Accessibility.Protected:

ILSpy/TreeNodes/MethodTreeNode.cs

@@ -17,6 +17,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Reflection.Metadata;
 using System.Windows.Media;
 
 using ICSharpCode.Decompiler;
@@ -37,14 +38,21 @@ namespace ICSharpCode.ILSpy.TreeNodes
 			this.MethodDefinition = method ?? throw new ArgumentNullException(nameof(method));
 		}
 
-		public override object Text => GetText(MethodDefinition, Language) + MethodDefinition.MetadataToken.ToSuffixString();
+		public override object Text => GetText(GetMethodDefinition(), Language) + MethodDefinition.MetadataToken.ToSuffixString();
+
+		private IMethod GetMethodDefinition()
+		{
+			return ((MetadataModule)MethodDefinition.ParentModule.PEFile
+				?.GetTypeSystemWithCurrentOptionsOrNull()
+				?.MainModule)?.GetDefinition((MethodDefinitionHandle)MethodDefinition.MetadataToken) ?? MethodDefinition;
+		}
 
 		public static object GetText(IMethod method, Language language)
 		{
 			return language.MethodToString(method, false, false, false);
 		}
 
-		public override object Icon => GetIcon(MethodDefinition);
+		public override object Icon => GetIcon(GetMethodDefinition());
 
 		public static ImageSource GetIcon(IMethod method)
 		{
@@ -102,7 +110,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public override bool IsPublicAPI {
 			get {
-				switch (MethodDefinition.Accessibility)
+				switch (GetMethodDefinition().Accessibility)
 				{
 					case Accessibility.Public:
 					case Accessibility.Protected:

ILSpy/TreeNodes/PropertyTreeNode.cs

@@ -17,14 +17,10 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
-using System.Reflection;
 using System.Reflection.Metadata;
 using System.Windows.Media;
 
 using ICSharpCode.Decompiler;
-using ICSharpCode.Decompiler.Metadata;
-
-using SRM = System.Reflection.Metadata;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
@@ -52,14 +48,21 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public IProperty PropertyDefinition { get; }
 
-		public override object Text => GetText(PropertyDefinition, Language) + PropertyDefinition.MetadataToken.ToSuffixString();
+		public override object Text => GetText(GetPropertyDefinition(), Language) + PropertyDefinition.MetadataToken.ToSuffixString();
+
+		private IProperty GetPropertyDefinition()
+		{
+			return ((MetadataModule)PropertyDefinition.ParentModule.PEFile
+				?.GetTypeSystemWithCurrentOptionsOrNull()
+				?.MainModule)?.GetDefinition((PropertyDefinitionHandle)PropertyDefinition.MetadataToken) ?? PropertyDefinition;
+		}
 
 		public static object GetText(IProperty property, Language language)
 		{
 			return language.PropertyToString(property, false, false, false);
 		}
 
-		public override object Icon => GetIcon(PropertyDefinition);
+		public override object Icon => GetIcon(GetPropertyDefinition());
 
 		public static ImageSource GetIcon(IProperty property)
 		{
@@ -84,7 +87,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public override bool IsPublicAPI {
 			get {
-				switch (PropertyDefinition.Accessibility)
+				switch (GetPropertyDefinition().Accessibility)
 				{
 					case Accessibility.Public:
 					case Accessibility.ProtectedOrInternal:

ILSpy/TreeNodes/TypeTreeNode.cs

@@ -41,12 +41,20 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public AssemblyTreeNode ParentAssemblyNode { get; }
 
-		public override object Text => this.Language.TypeToString(TypeDefinition, includeNamespace: false)
+		public override object Text => this.Language.TypeToString(GetTypeDefinition(), includeNamespace: false)
 			+ TypeDefinition.MetadataToken.ToSuffixString();
 
+		private ITypeDefinition GetTypeDefinition()
+		{
+			return ((MetadataModule)ParentAssemblyNode.LoadedAssembly
+				.GetPEFileOrNull()
+				?.GetTypeSystemWithCurrentOptionsOrNull()
+				?.MainModule).GetDefinition((SRM.TypeDefinitionHandle)TypeDefinition.MetadataToken);
+		}
+
 		public override bool IsPublicAPI {
 			get {
-				switch (TypeDefinition.Accessibility)
+				switch (GetTypeDefinition().Accessibility)
 				{
 					case Accessibility.Public:
 					case Accessibility.Protected:
@@ -120,7 +128,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		public override void Decompile(Language language, ITextOutput output, DecompilationOptions options)
 		{
-			language.DecompileType(TypeDefinition, output, options);
+			language.DecompileType(GetTypeDefinition(), output, options);
 		}
 
 		public override object Icon => GetIcon(TypeDefinition);