fix crash if no workshop addons are present

L4d2AddonsMgr.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 15
-VisualStudioVersion = 15.0.28307.168
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.30413.136
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "L4d2AddonsMgr", "L4d2AddonsMgr\L4d2AddonsMgr.csproj", "{E66621F6-7012-4D61-A1CB-E054671DE59A}"
 EndProject
@@ -15,17 +15,27 @@ EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
 		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
 		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Debug|x64.ActiveCfg = Debug|x64
+		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Debug|x64.Build.0 = Debug|x64
 		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Release|x64.ActiveCfg = Release|x64
+		{E66621F6-7012-4D61-A1CB-E054671DE59A}.Release|x64.Build.0 = Release|x64
 		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Debug|x64.ActiveCfg = Debug|x64
+		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Debug|x64.Build.0 = Debug|x64
 		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Release|Any CPU.Build.0 = Release|Any CPU
+		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Release|x64.ActiveCfg = Release|x64
+		{1DFFC99A-5D2A-478B-A01D-7808C9682CFF}.Release|x64.Build.0 = Release|x64
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

L4d2AddonsMgr/AddonsLibrary/GameDirAddonsLibrary.cs

@@ -56,9 +56,13 @@ public bool MoveNext() {
                     currentEnum.Dispose();
                     // Enumerate than list.
                     // https://docs.microsoft.com/en-us/dotnet/api/system.io.directory.enumeratefiles?view=netframework-4.8
-                    currentEnum = new DirectoryInfo(
-                        Path.Combine(basePath, CommonConsts.AddonsWorkshopDirectoryName)
-                    ).EnumerateFiles(CommonConsts.VpkFileSearchPattern).GetEnumerator();
+                    try {
+                        currentEnum = new DirectoryInfo(
+                            Path.Combine(basePath, CommonConsts.AddonsWorkshopDirectoryName)
+                        ).EnumerateFiles(CommonConsts.VpkFileSearchPattern).GetEnumerator();
+                    }catch (IOException) {
+                        return res;
+                    }
                     isEnumWorkshop = true;
                     return currentEnum.MoveNext();
                 }

L4d2AddonsMgr/App.config

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <configuration>
     <startup> 
-        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
     </startup>
 </configuration>

L4d2AddonsMgr/L4d2AddonsMgr.csproj

@@ -8,7 +8,7 @@
     <OutputType>WinExe</OutputType>
     <RootNamespace>L4d2AddonsMgr</RootNamespace>
     <AssemblyName>L4d2AddonsMgr</AssemblyName>
-    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <WarningLevel>4</WarningLevel>
@@ -37,6 +37,28 @@
   <PropertyGroup>
     <StartupObject>L4d2AddonsMgr.App</StartupObject>
   </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
+    <DebugSymbols>true</DebugSymbols>
+    <OutputPath>bin\x64\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <DebugType>full</DebugType>
+    <PlatformTarget>x64</PlatformTarget>
+    <LangVersion>7.3</LangVersion>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>true</Prefer32Bit>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
+    <OutputPath>bin\x64\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <Optimize>true</Optimize>
+    <DebugType>pdbonly</DebugType>
+    <PlatformTarget>x64</PlatformTarget>
+    <LangVersion>7.3</LangVersion>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>true</Prefer32Bit>
+  </PropertyGroup>
   <ItemGroup>
     <Reference Include="ChnCharInfo, Version=1.0.0.0, Culture=neutral, PublicKeyToken=18f031bd02e5e291, processorArchitecture=MSIL">
       <HintPath>..\packages\Microsoft.PinYinConverter.1.0.0\lib\ChnCharInfo.dll</HintPath>
@@ -119,6 +141,7 @@
     <Compile Include="MeowTask\MeowTask.cs" />
     <Compile Include="RealFolderPicker\FolderPicker.cs" />
     <Compile Include="Utils\CStringUtil.cs" />
+    <Compile Include="Utils\DependencyObjectExtension.cs" />
     <Compile Include="Utils\FileInodeComparer.cs" />
     <Compile Include="Utils\LocalizationUtil.cs" />
     <Compile Include="Utils\ProcessExtensions.cs" />

L4d2AddonsMgr/MainWindow.xaml

@@ -206,6 +206,12 @@
 
         <ListBox ScrollViewer.HorizontalScrollBarVisibility="Disabled" BorderThickness="0"
                  Name="AddonsListBox" ItemsSource="{Binding Addons.Files}" Grid.Row="2"
+                 PreviewMouseLeftButtonDown="AddonsListBox_PreviewMouseLeftButtonDown"
+                 PreviewMouseLeftButtonUp="AddonsListBox_PreviewMouseLeftButtonUp"
+                 PreviewMouseMove="AddonsListBox_PreviewMouseMove"
+                 AllowDrop="False" DragOver="AddonsListBox_DragValidate"
+                 DragEnter="AddonsListBox_DragValidate"
+                 Drop="AddonsListBox_Drop"
                             SelectionMode="Extended">
 
             <!--Templating? More like html than Android's adapter view.

L4d2AddonsMgr/MainWindow.xaml.cs

@@ -5,6 +5,7 @@
 using System.Linq;
 using System.Threading.Tasks;
 using System.Windows;
+using System.Windows.Controls;
 using System.Windows.Input;
 using System.Windows.Interop;
 using Fluent;
@@ -13,6 +14,7 @@
 using L4d2AddonsMgr.MeowTaskSpace;
 using L4d2AddonsMgr.OperationSpace;
 using L4d2AddonsMgr.RealFolderPicker;
+using L4d2AddonsMgr.Utils;
 
 namespace L4d2AddonsMgr {
     /// <summary>
@@ -64,9 +66,14 @@ public partial class MainWindow : RibbonWindow {
 
         private AddonsListTxt addonsList;
 
+        private Point dragPoint;
+
+        private DataObject dragObj;
+
         public MainWindow() {
             InitializeComponent();
             libraryPath = null;
+            dragPoint = new Point(-1.0, 0.0);
         }
 
         public MainWindow(string libraryPath) {
@@ -232,7 +239,8 @@ private async void RefreshListCommand_Invoke(object sender, ExecutedRoutedEventA
         private void ToggleFilterCommand_CanInvoke(object sender, CanExecuteRoutedEventArgs e) => e.CanExecute = (null != Addons) ? !Addons.IsLoading : false;
 
         private void ToggleFilterCommand_Invoke(object sender, ExecutedRoutedEventArgs e) {
-            if (e.Parameter is AddonsCollection.VpkFilter filter) Addons.ToggleFilter(filter);
+            if (e.Parameter is AddonsCollection.VpkFilter filter)
+                Addons.ToggleFilter(filter);
         }
 
         private void ToggleFilterDownloadSourceCommand_Invoke(object sender, ExecutedRoutedEventArgs e) {
@@ -259,10 +267,12 @@ private void OpAutoRenameCommand_Invoke(object sender, ExecutedRoutedEventArgs e
                     // https://stackoverflow.com/questions/541194/c-sharp-version-of-javas-synchronized-keyword
                     lock (AddonsListBox.SelectedItems) {
                         list = new List<VpkHolder>(AddonsListBox.SelectedItems.Count);
-                        foreach (object o in AddonsListBox.SelectedItems) list.Add((VpkHolder)o);
+                        foreach (object o in AddonsListBox.SelectedItems)
+                            list.Add((VpkHolder)o);
                     }
                     break;
-                default: return;
+                default:
+                    return;
                 }
                 Addons.IsLoading = true;
                 var renameTask = new AutoRenameTask(list, dialog.Model, gameDir, addonsList);
@@ -274,7 +284,8 @@ private void OpAutoRenameCommand_Invoke(object sender, ExecutedRoutedEventArgs e
 
                 // How would it be known by just guessing.
                 // https://www.wpf-tutorial.com/dialogs/the-messagebox/
-                if (res2 ?? false) MessageBox.Show("已完成。", "自动重命名");
+                if (res2 ?? false)
+                    MessageBox.Show("已完成。", "自动重命名");
                 Addons.IsLoading = false;
             }
         }
@@ -322,10 +333,68 @@ private void UpdateAccentColor() {
 
         private void LogErrorAndQuit(string text, Exception exception) {
             MessageBox.Show(text ?? string.Format("应用程序发生错误：{0}", exception.Message));
-            if (text != null) Debug.WriteLine(text);
+            if (text != null)
+                Debug.WriteLine(text);
             Debug.WriteLine(exception);
             Close();
         }
 
+        private void AddonsListBox_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) {
+            dragPoint = e.GetPosition(null);
+        }
+
+        private void AddonsListBox_PreviewMouseMove(object sender, MouseEventArgs e) {
+            if (dragPoint.X < 0.0)
+                return;
+            var pt = e.GetPosition(null);
+            double a = pt.X - dragPoint.X;
+            double b = pt.Y - dragPoint.Y;
+            if (a * a + b * b > SystemParameters.MinimumHorizontalDragDistance * SystemParameters.MinimumHorizontalDragDistance) {
+                dragPoint = new Point(-1.0, 0.0);
+                var list = sender as ListBox;
+                var li =
+                    ((DependencyObject)e.OriginalSource).FindAnchestor<ListBoxItem>();
+                if (li == null)
+                    return;
+                var holder = (VpkHolder)list.ItemContainerGenerator.ItemFromContainer(li);
+                var dobj = dragObj = new DataObject();
+                dobj.SetFileDropList(new System.Collections.Specialized.StringCollection() { holder.FileInf.FullName });
+                var ret = DragDrop.DoDragDrop(li, dobj, DragDropEffects.Copy | DragDropEffects.Move);
+                Console.WriteLine("ret = " + ret);
+                dragObj = null;
+                //if (ret.HasFlag(DragDropEffects.Move))
+                //Addons.ReloadFromLibrary();
+            }
+        }
+
+        private void AddonsListBox_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e) {
+            dragPoint = new Point(-1.0, 0.0);
+        }
+
+        private void AddonsListBox_DragValidate(object sender, DragEventArgs e) {
+            // No dropping to self.
+            if (dragObj != null) {
+                e.Effects = DragDropEffects.None;
+            } else if (e.Data.GetDataPresent(DataFormats.FileDrop))
+                e.Effects = DragDropEffects.Copy;
+            else
+                e.Effects = DragDropEffects.None;
+            e.Handled = true;
+        }
+
+        private void AddonsListBox_Drop(object sender, DragEventArgs e) {
+            // TODO support linking.
+            // TODO differentiate copy/move.
+            //if (e.Effects.HasFlag(DragDropEffects.Move)) {
+            //   e.Data
+            // }else 
+            MessageBox.Show("123");
+            if (e.Effects.HasFlag(DragDropEffects.Copy)) {
+                string[] files = (string[])e.Data.GetData(DataFormats.FileDrop);
+                foreach (string file in files) {
+                    Console.WriteLine(file);
+                }
+            }
+        }
     }
 }

L4d2AddonsMgr/Utils/DependencyObjectExtension.cs

@@ -0,0 +1,19 @@
+using System.Windows;
+using System.Windows.Media;
+
+namespace L4d2AddonsMgr.Utils {
+    public static class DependencyObjectExtension {
+
+        public static T FindAnchestor<T>(this DependencyObject current)
+    where T : DependencyObject {
+            do {
+                if (current is T) {
+                    return (T)current;
+                }
+                current = VisualTreeHelper.GetParent(current);
+            }
+            while (current != null);
+            return null;
+        }
+    }
+}

L4d2AddonsMgrTest/L4d2AddonsMgrTest.csproj

@@ -4,6 +4,8 @@
     <TargetFramework>netcoreapp2.1</TargetFramework>
 
     <IsPackable>false</IsPackable>
+
+    <Platforms>AnyCPU;x64</Platforms>
   </PropertyGroup>
 
   <ItemGroup>