1. Adapted to Steam's new LibraryFolders.vdf structure.

2. Improved Show in Explorer.
3. Improved stability.
4. Minor bug fixes in opening external addons library.

.editorconfig

@@ -0,0 +1,217 @@
+# 如果要从更高级别的目录继承 .editorconfig 设置，请删除以下行
+root = true
+
+# c# 文件
+[*.cs]
+
+#### Core EditorConfig 选项 ####
+
+# 缩进和间距
+indent_size = 4
+indent_style = space
+tab_width = 4
+
+# 新行首选项
+end_of_line = crlf
+insert_final_newline = false
+
+#### .NET 编码约定 ####
+
+# 组织 Using
+dotnet_separate_import_directive_groups = false
+dotnet_sort_system_directives_first = false
+file_header_template = unset
+
+# this. 和 Me. 首选项
+dotnet_style_qualification_for_event = false
+dotnet_style_qualification_for_field = false
+dotnet_style_qualification_for_method = false
+dotnet_style_qualification_for_property = false
+
+# 语言关键字与 bcl 类型首选项
+dotnet_style_predefined_type_for_locals_parameters_members = true:suggestion
+dotnet_style_predefined_type_for_member_access = true:suggestion
+
+# 括号首选项
+dotnet_style_parentheses_in_arithmetic_binary_operators = always_for_clarity:suggestion
+dotnet_style_parentheses_in_other_binary_operators = always_for_clarity:suggestion
+dotnet_style_parentheses_in_other_operators = never_if_unnecessary:suggestion
+dotnet_style_parentheses_in_relational_binary_operators = always_for_clarity:suggestion
+
+# 修饰符首选项
+dotnet_style_require_accessibility_modifiers = for_non_interface_members
+
+# 表达式级首选项
+dotnet_style_coalesce_expression = true
+dotnet_style_collection_initializer = true
+dotnet_style_explicit_tuple_names = true
+dotnet_style_namespace_match_folder = true
+dotnet_style_null_propagation = true
+dotnet_style_object_initializer = true
+dotnet_style_operator_placement_when_wrapping = beginning_of_line
+dotnet_style_prefer_auto_properties = true:suggestion
+dotnet_style_prefer_compound_assignment = true
+dotnet_style_prefer_conditional_expression_over_assignment = true:suggestion
+dotnet_style_prefer_conditional_expression_over_return = true:suggestion
+dotnet_style_prefer_inferred_anonymous_type_member_names = true
+dotnet_style_prefer_inferred_tuple_names = true
+dotnet_style_prefer_is_null_check_over_reference_equality_method = true:warning
+dotnet_style_prefer_simplified_boolean_expressions = true
+dotnet_style_prefer_simplified_interpolation = true
+
+# 字段首选项
+dotnet_style_readonly_field = true
+
+# 参数首选项
+dotnet_code_quality_unused_parameters = all
+
+# 禁止显示首选项
+dotnet_remove_unnecessary_suppression_exclusions = none
+
+# 新行首选项
+dotnet_style_allow_multiple_blank_lines_experimental = false:suggestion
+dotnet_style_allow_statement_immediately_after_block_experimental = true
+
+#### c# 编码约定 ####
+
+# var 首选项
+csharp_style_var_elsewhere = true:suggestion
+csharp_style_var_for_built_in_types = false
+csharp_style_var_when_type_is_apparent = true:suggestion
+
+# Expression-bodied 成员
+csharp_style_expression_bodied_accessors = when_on_single_line:suggestion
+csharp_style_expression_bodied_constructors = when_on_single_line:suggestion
+csharp_style_expression_bodied_indexers = when_on_single_line:suggestion
+csharp_style_expression_bodied_lambdas = true:suggestion
+csharp_style_expression_bodied_local_functions = when_on_single_line:suggestion
+csharp_style_expression_bodied_methods = when_on_single_line:suggestion
+csharp_style_expression_bodied_operators = when_on_single_line:suggestion
+csharp_style_expression_bodied_properties = when_on_single_line:suggestion
+
+# 模式匹配首选项
+csharp_style_pattern_matching_over_as_with_null_check = true
+csharp_style_pattern_matching_over_is_with_cast_check = true
+csharp_style_prefer_not_pattern = true
+csharp_style_prefer_pattern_matching = true:suggestion
+csharp_style_prefer_switch_expression = true
+
+# Null 检查首选项
+csharp_style_conditional_delegate_call = true
+
+# 修饰符首选项
+csharp_prefer_static_local_function = true
+csharp_preferred_modifier_order = public,private,protected,internal,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,volatile,async
+
+# 代码块首选项
+csharp_prefer_braces = when_multiline:suggestion
+csharp_prefer_simple_using_statement = true
+
+# 表达式级首选项
+csharp_prefer_simple_default_expression = true
+csharp_style_deconstructed_variable_declaration = true
+csharp_style_implicit_object_creation_when_type_is_apparent = true
+csharp_style_inlined_variable_declaration = true
+csharp_style_pattern_local_over_anonymous_function = true
+csharp_style_prefer_index_operator = true
+csharp_style_prefer_range_operator = true
+csharp_style_throw_expression = true
+csharp_style_unused_value_assignment_preference = discard_variable
+csharp_style_unused_value_expression_statement_preference = discard_variable
+
+# "using" 指令首选项
+csharp_using_directive_placement = outside_namespace:suggestion
+
+# 新行首选项
+csharp_style_allow_blank_line_after_colon_in_constructor_initializer_experimental = true
+csharp_style_allow_blank_lines_between_consecutive_braces_experimental = true
+csharp_style_allow_embedded_statements_on_same_line_experimental = true
+
+#### C# 格式规则 ####
+
+# 新行首选项
+csharp_new_line_before_catch = false
+csharp_new_line_before_else = false
+csharp_new_line_before_finally = false
+csharp_new_line_before_members_in_anonymous_types = false
+csharp_new_line_before_members_in_object_initializers = false
+csharp_new_line_before_open_brace = none
+csharp_new_line_between_query_expression_clauses = true
+
+# 缩进首选项
+csharp_indent_block_contents = true
+csharp_indent_braces = false
+csharp_indent_case_contents = true
+csharp_indent_case_contents_when_block = true
+csharp_indent_labels = one_less_than_current
+csharp_indent_switch_labels = true
+
+# 空格键首选项
+csharp_space_after_cast = false
+csharp_space_after_colon_in_inheritance_clause = true
+csharp_space_after_comma = true
+csharp_space_after_dot = false
+csharp_space_after_keywords_in_control_flow_statements = true
+csharp_space_after_semicolon_in_for_statement = true
+csharp_space_around_binary_operators = before_and_after
+csharp_space_around_declaration_statements = false
+csharp_space_before_colon_in_inheritance_clause = true
+csharp_space_before_comma = false
+csharp_space_before_dot = false
+csharp_space_before_open_square_brackets = false
+csharp_space_before_semicolon_in_for_statement = false
+csharp_space_between_empty_square_brackets = false
+csharp_space_between_method_call_empty_parameter_list_parentheses = false
+csharp_space_between_method_call_name_and_opening_parenthesis = false
+csharp_space_between_method_call_parameter_list_parentheses = false
+csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
+csharp_space_between_method_declaration_name_and_open_parenthesis = false
+csharp_space_between_method_declaration_parameter_list_parentheses = false
+csharp_space_between_parentheses = false
+csharp_space_between_square_brackets = false
+
+# 包装首选项
+csharp_preserve_single_line_blocks = false
+csharp_preserve_single_line_statements = false
+
+#### 命名样式 ####
+
+# 命名规则
+
+dotnet_naming_rule.interface_should_be_begins_with_i.severity = suggestion
+dotnet_naming_rule.interface_should_be_begins_with_i.symbols = interface
+dotnet_naming_rule.interface_should_be_begins_with_i.style = begins_with_i
+
+dotnet_naming_rule.types_should_be_pascal_case.severity = suggestion
+dotnet_naming_rule.types_should_be_pascal_case.symbols = types
+dotnet_naming_rule.types_should_be_pascal_case.style = pascal_case
+
+dotnet_naming_rule.non_field_members_should_be_pascal_case.severity = suggestion
+dotnet_naming_rule.non_field_members_should_be_pascal_case.symbols = non_field_members
+dotnet_naming_rule.non_field_members_should_be_pascal_case.style = pascal_case
+
+# 符号规范
+
+dotnet_naming_symbols.interface.applicable_kinds = interface
+dotnet_naming_symbols.interface.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
+dotnet_naming_symbols.interface.required_modifiers = 
+
+dotnet_naming_symbols.types.applicable_kinds = class, struct, interface, enum
+dotnet_naming_symbols.types.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
+dotnet_naming_symbols.types.required_modifiers = 
+
+dotnet_naming_symbols.non_field_members.applicable_kinds = property, event, method
+dotnet_naming_symbols.non_field_members.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
+dotnet_naming_symbols.non_field_members.required_modifiers = 
+
+# 命名样式
+
+dotnet_naming_style.pascal_case.required_prefix = 
+dotnet_naming_style.pascal_case.required_suffix = 
+dotnet_naming_style.pascal_case.word_separator = 
+dotnet_naming_style.pascal_case.capitalization = pascal_case
+
+dotnet_naming_style.begins_with_i.required_prefix = I
+dotnet_naming_style.begins_with_i.required_suffix = 
+dotnet_naming_style.begins_with_i.word_separator = 
+dotnet_naming_style.begins_with_i.capitalization = pascal_case

L4d2AddonsMgr.sln

@@ -9,6 +9,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "L4d2AddonsMgrTest", "L4d2Ad
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{95174B3B-1FB5-4AE4-BFD6-A826054249B6}"
 	ProjectSection(SolutionItems) = preProject
+		.editorconfig = .editorconfig
 		ReadMe.md = ReadMe.md
 	EndProjectSection
 EndProject

L4d2AddonsMgr/AcfFile/AcfFile.cs

@@ -50,7 +50,7 @@ public static Node GetNode(Node node, string key) {
         public static Node GetNodeIgnoreCase(Node node, string key) {
             if (!(node is CompoundNode cnode)) return null;
             foreach (var child in cnode.Value) {
-                if (key.ToLowerInvariant() == child.Key.ToLowerInvariant()) return child;
+                if (key.ToLowerInvariant() == child.Key?.ToLowerInvariant()) return child;
             }
             return null;
         }
@@ -184,7 +184,7 @@ public Node GetNodeByPath(params string[] path) {
             Node node = Root;
             foreach (var seg in path) {
                 if (node == null) return null;
-                node = GetNode(node, seg);
+                node = GetNodeIgnoreCase(node, seg);
             }
             return node;
         }

L4d2AddonsMgr/AddonsCollection.cs

@@ -73,8 +73,12 @@ public AddonsCollection(AddonsLibrary addonsLibrary) {
 
         public void ReloadFromLibrary() {
             Application.Current.Dispatcher.Invoke(() => Clear());
-            foreach (var item in Library)
-                Application.Current.Dispatcher.Invoke(new Action(() => Add(item)));
+            try {
+                foreach (var item in Library)
+                    Application.Current.Dispatcher.Invoke(new Action(() => Add(item)));
+            } catch (Exception) {
+                //
+            }
         }
 
         private void Add(VpkHolder vpkHolder) {

L4d2AddonsMgr/ExplorerInterop.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace L4d2AddonsMgr {
+    class ExplorerInterop {
+        [DllImport("shell32.dll", SetLastError = true)]
+        public static extern int SHOpenFolderAndSelectItems(IntPtr pidlFolder, uint cidl, [In, MarshalAs(UnmanagedType.LPArray)] IntPtr[] apidl, uint dwFlags);
+
+        [DllImport("shell32.dll", SetLastError = true)]
+        public static extern void SHParseDisplayName([MarshalAs(UnmanagedType.LPWStr)] string name, IntPtr bindingContext, [Out] out IntPtr pidl, uint sfgaoIn, [Out] out uint psfgaoOut);
+
+        public static void OpenFolderAndSelectItem(string folderPath, string file) {
+            IntPtr nativeFolder;
+            uint psfgaoOut;
+            SHParseDisplayName(folderPath, IntPtr.Zero, out nativeFolder, 0, out psfgaoOut);
+
+            if (nativeFolder == IntPtr.Zero) {
+                // Log error, can't find folder
+                return;
+            }
+
+            IntPtr nativeFile;
+            SHParseDisplayName(Path.Combine(folderPath, file), IntPtr.Zero, out nativeFile, 0, out psfgaoOut);
+
+            IntPtr[] fileArray;
+            if (nativeFile == IntPtr.Zero) {
+                // Open the folder without the file selected if we can't find the file
+                fileArray = new IntPtr[0];
+            } else {
+                fileArray = new IntPtr[] { nativeFile };
+            }
+
+            SHOpenFolderAndSelectItems(nativeFolder, (uint)fileArray.Length, fileArray, 0);
+
+            Marshal.FreeCoTaskMem(nativeFolder);
+            if (nativeFile != IntPtr.Zero) {
+                Marshal.FreeCoTaskMem(nativeFile);
+            }
+        }
+    }
+}

L4d2AddonsMgr/GameDirLocator.cs

@@ -23,11 +23,18 @@ public static string FindGameInLibraries(string baseDir) {
                 var conf = AcfFile.ParseString(confTxt, true);
                 var infoNode = conf.GetNodeByPath(CommonConsts.SteamLibraryConfigVdfFileRootNode);
                 foreach (var node in (infoNode as AcfFile.CompoundNode).Value) {
-                    if (!(node is AcfFile.LeafNode)) continue;
+                    //if (!(node is AcfFile.LeafNode)) continue;
                     try {
                         int.Parse(node.Key);
+                        var libPath = (node as AcfFile.LeafNode)?.Value;
+                        if (libPath == null) {
+                            var comNode = node as AcfFile.CompoundNode;
+                            if ((comNode.GetChild("apps") as AcfFile.CompoundNode)?.GetChild("550") == null)
+                                continue;
+                            libPath = (comNode.GetChild("path") as AcfFile.LeafNode).Value;
+                        }
                         gamePath = FindGameInLibrary(
-                            Path.Combine((node as AcfFile.LeafNode).Value, CommonConsts.SteamAppsDirectoryName)
+                            Path.Combine(libPath, CommonConsts.SteamAppsDirectoryName)
                         );
                         if (gamePath != null) {
                             break;

L4d2AddonsMgr/L4d2AddonsMgr.csproj

@@ -116,6 +116,7 @@
     <Compile Include="AddonsLibrary\GameDirAddonsLibrary.cs" />
     <Compile Include="CommonConsts.cs" />
     <Compile Include="Controls\MeowWrapPanel.cs" />
+    <Compile Include="ExplorerInterop.cs" />
     <Compile Include="GameDirLocator.cs" />
     <Compile Include="MeowTask\CancelConfirmationDialog.xaml.cs">
       <DependentUpon>CancelConfirmationDialog.xaml</DependentUpon>