Port to .NET Standard 2.0 - so far works only on .NET Core derived runtimes and .NET Framework, but in the later case the user has to manually copy the dll

NativeFileDialogSharp.sln

@@ -1,22 +1,51 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NativeFileDialogSharp", "NativeFileDialogSharp\NativeFileDialogSharp.csproj", "{4127F279-9FD5-4C37-B904-242C124C1A07}"
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31919.166
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NativeFileDialogSharp", "NativeFileDialogSharp\NativeFileDialogSharp.csproj", "{4127F279-9FD5-4C37-B904-242C124C1A07}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NativeFileDialogSharpSandbox", "NativeFileDialogSharpSandbox\NativeFileDialogSharpSandbox.csproj", "{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NativeFileDialogSharpSandbox", "NativeFileDialogSharpSandbox\NativeFileDialogSharpSandbox.csproj", "{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NativeFileDialogSharpSandboxNetFramework", "NativeFileDialogSharpSandboxNetFramework\NativeFileDialogSharpSandboxNetFramework.csproj", "{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}"
 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
 		{4127F279-9FD5-4C37-B904-242C124C1A07}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{4127F279-9FD5-4C37-B904-242C124C1A07}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4127F279-9FD5-4C37-B904-242C124C1A07}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{4127F279-9FD5-4C37-B904-242C124C1A07}.Debug|x64.Build.0 = Debug|Any CPU
 		{4127F279-9FD5-4C37-B904-242C124C1A07}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{4127F279-9FD5-4C37-B904-242C124C1A07}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4127F279-9FD5-4C37-B904-242C124C1A07}.Release|x64.ActiveCfg = Release|Any CPU
+		{4127F279-9FD5-4C37-B904-242C124C1A07}.Release|x64.Build.0 = Release|Any CPU
 		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Debug|x64.Build.0 = Debug|Any CPU
 		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Release|x64.ActiveCfg = Release|Any CPU
+		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Release|x64.Build.0 = Release|Any CPU
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Debug|x64.ActiveCfg = Debug|x64
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Debug|x64.Build.0 = Debug|x64
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Release|x64.ActiveCfg = Release|x64
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Release|x64.Build.0 = Release|x64
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {124CB415-A372-4268-9C13-330A0F1093C2}
 	EndGlobalSection
 EndGlobal

NativeFileDialogSharp/Native/NativeFunctions.cs

@@ -1,56 +1,97 @@
 using System;
 using System.Runtime.InteropServices;
 
-namespace NativeFileDialogSharp.Native;
+namespace NativeFileDialogSharp.Native
-
-public struct nfdpathset_t
 {
-    public IntPtr buf;
+    public struct nfdpathset_t
-    public IntPtr indices;
+    {
-    public UIntPtr count;
+        public IntPtr buf;
-}
+        public IntPtr indices;
-
+        public UIntPtr count;
-public enum nfdresult_t
+    }
-{
+
-    NFD_ERROR,
+    public enum nfdresult_t
-    NFD_OKAY,
+    {
-    NFD_CANCEL
+        NFD_ERROR,
-}
+        NFD_OKAY,
-
+        NFD_CANCEL
-public static class NativeFunctions
+    }
-{
+
-    public const string LibraryName = "nfd";
+    public static class NativeFunctions
-    
+    {
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public const string LibraryName = "nfd";
-    public static extern unsafe nfdresult_t NFD_OpenDialog(byte* filterList, byte* defaultPath, out IntPtr outPath);
+
-    
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe nfdresult_t NFD_OpenDialog(byte* filterList, byte* defaultPath, out IntPtr outPath);
-    public static extern unsafe nfdresult_t NFD_OpenDialogMultiple(byte* filterList, byte* defaultPath, nfdpathset_t* outPaths);
+
-    
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe nfdresult_t NFD_OpenDialogMultiple(byte* filterList, byte* defaultPath,
-    public static extern unsafe nfdresult_t NFD_SaveDialog(byte* filterList, byte* defaultPath, out IntPtr outPath);
+            nfdpathset_t* outPaths);
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe nfdresult_t NFD_PickFolder(byte* defaultPath, out IntPtr outPath);
+        public static extern unsafe nfdresult_t NFD_SaveDialog(byte* filterList, byte* defaultPath, out IntPtr outPath);
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe byte* NFD_GetError();
+        public static extern unsafe nfdresult_t NFD_PickFolder(byte* defaultPath, out IntPtr outPath);
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe UIntPtr NFD_PathSet_GetCount(nfdpathset_t* pathSet);
+        public static extern unsafe byte* NFD_GetError();
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe byte* NFD_PathSet_GetPath(nfdpathset_t* pathSet, UIntPtr index);
+        public static extern unsafe UIntPtr NFD_PathSet_GetCount(nfdpathset_t* pathSet);
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe void NFD_PathSet_Free(nfdpathset_t* pathSet);
+        public static extern unsafe byte* NFD_PathSet_GetPath(nfdpathset_t* pathSet, UIntPtr index);
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe void NFD_Dummy();
+        public static extern unsafe void NFD_PathSet_Free(nfdpathset_t* pathSet);
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe IntPtr NFD_Malloc(UIntPtr bytes);
+        public static extern unsafe void NFD_Dummy();
-    
+
-    [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
-    public static extern unsafe void NFD_Free(IntPtr ptr);
+        public static extern unsafe IntPtr NFD_Malloc(UIntPtr bytes);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe void NFD_Free(IntPtr ptr);
+    }
+    
+    public static class NativeFunctions32
+    {
+        public const string LibraryName = "nfd_x86";
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe nfdresult_t NFD_OpenDialog(byte* filterList, byte* defaultPath, out IntPtr outPath);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe nfdresult_t NFD_OpenDialogMultiple(byte* filterList, byte* defaultPath,
+            nfdpathset_t* outPaths);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe nfdresult_t NFD_SaveDialog(byte* filterList, byte* defaultPath, out IntPtr outPath);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe nfdresult_t NFD_PickFolder(byte* defaultPath, out IntPtr outPath);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe byte* NFD_GetError();
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe UIntPtr NFD_PathSet_GetCount(nfdpathset_t* pathSet);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe byte* NFD_PathSet_GetPath(nfdpathset_t* pathSet, UIntPtr index);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe void NFD_PathSet_Free(nfdpathset_t* pathSet);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe void NFD_Dummy();
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe IntPtr NFD_Malloc(UIntPtr bytes);
+
+        [DllImport(LibraryName, CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        public static extern unsafe void NFD_Free(IntPtr ptr);
+    }
 }

NativeFileDialogSharp/NativeFileDialogSharp.csproj

@@ -1,9 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <LangVersion>10</LangVersion>
+        <LangVersion>7.3</LangVersion>
-        <PackageVersion>0.2.5</PackageVersion>
+        <PackageVersion>0.5.0</PackageVersion>
-        <TargetFramework>net6.0</TargetFramework>
         <Nullable>disable</Nullable>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
         <PackageLicenseExpression>Zlib</PackageLicenseExpression>
@@ -11,6 +10,7 @@
         <PackageProjectUrl>https://github.com/milleniumbug/NativeFileDialogSharp</PackageProjectUrl>
         <RepositoryUrl>https://github.com/milleniumbug/NativeFileDialogSharp</RepositoryUrl>
         <Description>Cross-platform native file dialog controls for Windows, Linux and macOS</Description>
+        <TargetFramework>netstandard2.0</TargetFramework>
     </PropertyGroup>
 
     <ItemGroup>

NativeFileDialogSharp/NativeWrappers.cs

@@ -1,156 +1,168 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Text;
 using NativeFileDialogSharp.Native;
 
-namespace NativeFileDialogSharp;
+namespace NativeFileDialogSharp
-
-public static class Dialog
 {
-    private static byte[] ToUtf8(string s)
+    public static class Dialog
     {
-        var byteCount = Encoding.UTF8.GetByteCount(s);
+        private static readonly Encoder utf8encoder = Encoding.UTF8.GetEncoder();
-        var bytes = new byte[byteCount + 1];
-        Encoding.UTF8.GetBytes(s.AsSpan(), bytes.AsSpan());
-        return bytes;
-    }
 
-    private static unsafe Span<byte> MakeSpanFromNullTerminatedString(byte* nullTerminatedString)
+        private static unsafe byte[] ToUtf8(string s)
-    {
-        int count = 0;
-        var ptr = nullTerminatedString;
-        while (*ptr != 0)
         {
-            ptr++;
+            var byteCount = Encoding.UTF8.GetByteCount(s);
-            count++;
+            var bytes = new byte[byteCount + 1];
+            fixed (byte* o = bytes)
+            fixed (char* input = s)
+            {
+                utf8encoder.Convert(input, s.Length, o, bytes.Length, true, out _, out var _,
+                    out var completed);
+                Debug.Assert(completed);
+            }
+
+            return bytes;
         }
 
-        return new Span<byte>(nullTerminatedString, count);
+        private static unsafe int GetNullTerminatedStringLength(byte* nullTerminatedString)
-    }
-
-    private static string FromUtf8(ReadOnlySpan<byte> input)
-    {
-        return Encoding.UTF8.GetString(input);
-    }
-
-    public static unsafe DialogResult FileOpen(string filterList = null, string defaultPath = null)
-    {
-        fixed (byte* filterListNts = filterList != null ? ToUtf8(filterList) : null)
-        fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
         {
-            string path = null;
+            int count = 0;
-            string errorMessage = null;
+            var ptr = nullTerminatedString;
-            var result = NativeFunctions.NFD_OpenDialog(filterListNts, defaultPathNts, out IntPtr outPathIntPtr);
+            while (*ptr != 0)
-            if (result == nfdresult_t.NFD_ERROR)
             {
-                errorMessage = FromUtf8(MakeSpanFromNullTerminatedString(NativeFunctions.NFD_GetError()));
+                ptr++;
-            }
+                count++;
-            else if (result == nfdresult_t.NFD_OKAY)
-            {
-                var outPathNts = (byte*)outPathIntPtr.ToPointer();
-                path = FromUtf8(MakeSpanFromNullTerminatedString(outPathNts));
-                NativeFunctions.NFD_Free(outPathIntPtr);
             }
 
-            return new DialogResult(result, path, null, errorMessage);
+            return count;
         }
-    }
 
-    public static unsafe DialogResult FileSave(string filterList = null, string defaultPath = null)
+        private static unsafe string FromUtf8(byte* nullTerminatedString)
-    {
-        fixed (byte* filterListNts = filterList != null ? ToUtf8(filterList) : null)
-        fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
         {
-            string path = null;
+            return Encoding.UTF8.GetString(nullTerminatedString, GetNullTerminatedStringLength(nullTerminatedString));
-            string errorMessage = null;
-            var result = NativeFunctions.NFD_SaveDialog(filterListNts, defaultPathNts, out IntPtr outPathIntPtr);
-            if (result == nfdresult_t.NFD_ERROR)
-            {
-                errorMessage = FromUtf8(MakeSpanFromNullTerminatedString(NativeFunctions.NFD_GetError()));
-            }
-            else if (result == nfdresult_t.NFD_OKAY)
-            {
-                var outPathNts = (byte*)outPathIntPtr.ToPointer();
-                path = FromUtf8(MakeSpanFromNullTerminatedString(outPathNts));
-                NativeFunctions.NFD_Free(outPathIntPtr);
-            }
-
-            return new DialogResult(result, path, null, errorMessage);
         }
-    }
 
-    public static unsafe DialogResult FolderPicker(string defaultPath = null)
+        public static unsafe DialogResult FileOpen(string filterList = null, string defaultPath = null)
-    {
-        fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
         {
-            string path = null;
+            fixed (byte* filterListNts = filterList != null ? ToUtf8(filterList) : null)
-            string errorMessage = null;
+            fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
-            var result = NativeFunctions.NFD_PickFolder(defaultPathNts, out IntPtr outPathIntPtr);
-            if (result == nfdresult_t.NFD_ERROR)
             {
-                errorMessage = FromUtf8(MakeSpanFromNullTerminatedString(NativeFunctions.NFD_GetError()));
+                string path = null;
-            }
+                string errorMessage = null;
-            else if (result == nfdresult_t.NFD_OKAY)
+                var result = NativeFunctions.NFD_OpenDialog(filterListNts, defaultPathNts, out IntPtr outPathIntPtr);
-            {
+                if (result == nfdresult_t.NFD_ERROR)
-                var outPathNts = (byte*)outPathIntPtr.ToPointer();
-                path = FromUtf8(MakeSpanFromNullTerminatedString(outPathNts));
-                NativeFunctions.NFD_Free(outPathIntPtr);
-            }
-
-            return new DialogResult(result, path, null, errorMessage);
-        }
-    }
-    
-    public static unsafe DialogResult FileOpenMultiple(string filterList = null, string defaultPath = null)
-    {
-        fixed (byte* filterListNts = filterList != null ? ToUtf8(filterList) : null)
-        fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
-        {
-            List<string> paths = null;
-            string errorMessage = null;
-            nfdpathset_t pathSet;
-            var result = NativeFunctions.NFD_OpenDialogMultiple(filterListNts, defaultPathNts, &pathSet);
-            if (result == nfdresult_t.NFD_ERROR)
-            {
-                errorMessage = FromUtf8(MakeSpanFromNullTerminatedString(NativeFunctions.NFD_GetError()));
-            }
-            else if (result == nfdresult_t.NFD_OKAY)
-            {
-                var pathCount = (int)NativeFunctions.NFD_PathSet_GetCount(&pathSet).ToUInt32();
-                paths = new List<string>(pathCount);
-                for (int i = 0; i < pathCount; i++)
                 {
-                    paths.Add(FromUtf8(MakeSpanFromNullTerminatedString(NativeFunctions.NFD_PathSet_GetPath(&pathSet, new UIntPtr((uint)i)))));
+                    errorMessage = FromUtf8(NativeFunctions.NFD_GetError());
+                }
+                else if (result == nfdresult_t.NFD_OKAY)
+                {
+                    var outPathNts = (byte*)outPathIntPtr.ToPointer();
+                    path = FromUtf8(outPathNts);
+                    NativeFunctions.NFD_Free(outPathIntPtr);
                 }
-                NativeFunctions.NFD_PathSet_Free(&pathSet);
-            }
 
-            return new DialogResult(result, null, paths, errorMessage);
+                return new DialogResult(result, path, null, errorMessage);
+            }
+        }
+
+        public static unsafe DialogResult FileSave(string filterList = null, string defaultPath = null)
+        {
+            fixed (byte* filterListNts = filterList != null ? ToUtf8(filterList) : null)
+            fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
+            {
+                string path = null;
+                string errorMessage = null;
+                var result = NativeFunctions.NFD_SaveDialog(filterListNts, defaultPathNts, out IntPtr outPathIntPtr);
+                if (result == nfdresult_t.NFD_ERROR)
+                {
+                    errorMessage = FromUtf8(NativeFunctions.NFD_GetError());
+                }
+                else if (result == nfdresult_t.NFD_OKAY)
+                {
+                    var outPathNts = (byte*)outPathIntPtr.ToPointer();
+                    path = FromUtf8(outPathNts);
+                    NativeFunctions.NFD_Free(outPathIntPtr);
+                }
+
+                return new DialogResult(result, path, null, errorMessage);
+            }
+        }
+
+        public static unsafe DialogResult FolderPicker(string defaultPath = null)
+        {
+            fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
+            {
+                string path = null;
+                string errorMessage = null;
+                var result = NativeFunctions.NFD_PickFolder(defaultPathNts, out IntPtr outPathIntPtr);
+                if (result == nfdresult_t.NFD_ERROR)
+                {
+                    errorMessage = FromUtf8(NativeFunctions.NFD_GetError());
+                }
+                else if (result == nfdresult_t.NFD_OKAY)
+                {
+                    var outPathNts = (byte*)outPathIntPtr.ToPointer();
+                    path = FromUtf8(outPathNts);
+                    NativeFunctions.NFD_Free(outPathIntPtr);
+                }
+
+                return new DialogResult(result, path, null, errorMessage);
+            }
+        }
+
+        public static unsafe DialogResult FileOpenMultiple(string filterList = null, string defaultPath = null)
+        {
+            fixed (byte* filterListNts = filterList != null ? ToUtf8(filterList) : null)
+            fixed (byte* defaultPathNts = defaultPath != null ? ToUtf8(defaultPath) : null)
+            {
+                List<string> paths = null;
+                string errorMessage = null;
+                nfdpathset_t pathSet;
+                var result = NativeFunctions.NFD_OpenDialogMultiple(filterListNts, defaultPathNts, &pathSet);
+                if (result == nfdresult_t.NFD_ERROR)
+                {
+                    errorMessage = FromUtf8(NativeFunctions.NFD_GetError());
+                }
+                else if (result == nfdresult_t.NFD_OKAY)
+                {
+                    var pathCount = (int)NativeFunctions.NFD_PathSet_GetCount(&pathSet).ToUInt32();
+                    paths = new List<string>(pathCount);
+                    for (int i = 0; i < pathCount; i++)
+                    {
+                        paths.Add(FromUtf8(NativeFunctions.NFD_PathSet_GetPath(&pathSet, new UIntPtr((uint)i))));
+                    }
+
+                    NativeFunctions.NFD_PathSet_Free(&pathSet);
+                }
+
+                return new DialogResult(result, null, paths, errorMessage);
+            }
+        }
+    }
+
+    public class DialogResult
+    {
+        private readonly nfdresult_t result;
+
+        public string Path { get; }
+
+        public IReadOnlyList<string> Paths { get; }
+
+        public bool IsError => result == nfdresult_t.NFD_ERROR;
+
+        public string ErrorMessage { get; }
+
+        public bool IsCancelled => result == nfdresult_t.NFD_CANCEL;
+
+        public bool IsOk => result == nfdresult_t.NFD_OKAY;
+
+        internal DialogResult(nfdresult_t result, string path, IReadOnlyList<string> paths, string errorMessage)
+        {
+            this.result = result;
+            Path = path;
+            Paths = paths;
+            ErrorMessage = errorMessage;
         }
     }
 }
-
-public class DialogResult
-{
-    private readonly nfdresult_t result;
-    
-    public string Path { get; }
-    
-    public IReadOnlyList<string> Paths { get; }
-
-    public bool IsError => result == nfdresult_t.NFD_ERROR;
-    
-    public string ErrorMessage { get; }
-
-    public bool IsCancelled => result == nfdresult_t.NFD_CANCEL;
-
-    public bool IsOk => result == nfdresult_t.NFD_OKAY;
-
-    internal DialogResult(nfdresult_t result, string path, IReadOnlyList<string> paths, string errorMessage)
-    {
-        this.result = result;
-        Path = path;
-        Paths = paths;
-        ErrorMessage = errorMessage;
-    }
-}

NativeFileDialogSharpSandbox/NativeFileDialogSharpSandbox.csproj

@@ -8,7 +8,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="NativeFileDialogSharp" Version="0.2.4" />
+      <PackageReference Include="NativeFileDialogSharp" Version="0.5.0" />
     </ItemGroup>
 
 </Project>

NativeFileDialogSharpSandbox/Program.cs

@@ -1,14 +1,26 @@
-// See https://aka.ms/new-console-template for more information
+using NativeFileDialogSharp;
-
 using System;
-using NativeFileDialogSharp;
-using NativeFileDialogSharp.Native;
 
-var result = Dialog.FileOpenMultiple();
+namespace NativeFileDialogSharpSandbox
-
-Console.WriteLine($"Path: {result.Path}, IsError {result.IsError}, IsOk {result.IsOk}, IsCancelled {result.IsCancelled}, ErrorMessage {result.ErrorMessage}");
-if (result.Paths != null)
 {
-    Console.WriteLine("Paths");
+    internal class Program
-    Console.WriteLine(string.Join("\n", result.Paths));
+    {
+        static void Main(string[] args)
+        {
+            PrintResult(Dialog.FileOpenMultiple("pdf", null));
+            PrintResult(Dialog.FileOpen(null));
+            PrintResult(Dialog.FileSave(null));
+            PrintResult(Dialog.FolderPicker(null));
+        }
+
+        static void PrintResult(DialogResult result)
+        {
+            Console.WriteLine($"Path: {result.Path}, IsError {result.IsError}, IsOk {result.IsOk}, IsCancelled {result.IsCancelled}, ErrorMessage {result.ErrorMessage}");
+            if (result.Paths != null)
+            {
+                Console.WriteLine("Paths");
+                Console.WriteLine(string.Join("\n", result.Paths));
+            }
+        }
+    }
 }

NativeFileDialogSharpSandboxNetFramework/App.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2"/>
+    </startup>
+</configuration>

NativeFileDialogSharpSandboxNetFramework/NativeFileDialogSharpSandboxNetFramework.csproj

@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <RootNamespace>NativeFileDialogSharpSandboxNetFramework</RootNamespace>
+    <AssemblyName>NativeFileDialogSharpSandboxNetFramework</AssemblyName>
+    <TargetFrameworkVersion>v4.6.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <Deterministic>true</Deterministic>
+    <TargetFrameworkProfile />
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <PlatformTarget>x86</PlatformTarget>
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </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>
+    <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>
+    <Prefer32Bit>true</Prefer32Bit>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="NativeFileDialogSharp, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\NativeFileDialogSharp.0.4.4\lib\net461\NativeFileDialogSharp.dll</HintPath>
+    </Reference>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="App.config" />
+    <None Include="packages.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>

NativeFileDialogSharpSandboxNetFramework/Program.cs

@@ -0,0 +1,26 @@
+using NativeFileDialogSharp;
+using System;
+
+namespace NativeFileDialogSharpSandboxNetFramework
+{
+    internal class Program
+    {
+        static void Main(string[] args)
+        {
+            PrintResult(Dialog.FileOpenMultiple("pdf", null));
+            PrintResult(Dialog.FileOpen(null));
+            PrintResult(Dialog.FileSave(null));
+            PrintResult(Dialog.FolderPicker(null));
+        }
+
+        static void PrintResult(DialogResult result)
+        {
+            Console.WriteLine($"Path: {result.Path}, IsError {result.IsError}, IsOk {result.IsOk}, IsCancelled {result.IsCancelled}, ErrorMessage {result.ErrorMessage}");
+            if (result.Paths != null)
+            {
+                Console.WriteLine("Paths");
+                Console.WriteLine(string.Join("\n", result.Paths));
+            }
+        }
+    }
+}

NativeFileDialogSharpSandboxNetFramework/Properties/AssemblyInfo.cs

@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("NativeFileDialogSharpSandboxNetFramework")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("NativeFileDialogSharpSandboxNetFramework")]
+[assembly: AssemblyCopyright("Copyright ©  2021")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("0fd91168-d8f5-4776-8d91-cb9b9c55aa1b")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

NativeFileDialogSharpSandboxNetFramework/packages.config

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Microsoft.NETCore.Platforms" version="6.0.1" targetFramework="net462" />
+  <package id="NativeFileDialogSharp" version="0.4.4" targetFramework="net462" />
+</packages>