Version 0.5.0 - tested with 32-bit and 64-bit version of Framework

NativeFileDialogSharp.sln

@@ -13,34 +13,48 @@ Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
 		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
 		Release|Any CPU = Release|Any CPU
 		Release|x64 = Release|x64
+		Release|x86 = Release|x86
 	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}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{4127F279-9FD5-4C37-B904-242C124C1A07}.Debug|x86.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
+		{4127F279-9FD5-4C37-B904-242C124C1A07}.Release|x86.ActiveCfg = Release|Any CPU
+		{4127F279-9FD5-4C37-B904-242C124C1A07}.Release|x86.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}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Debug|x86.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
+		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Release|x86.ActiveCfg = Release|Any CPU
+		{427E5F76-8418-4EA3-9AA3-C1DBFDE0478F}.Release|x86.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}.Debug|x86.ActiveCfg = Debug|x86
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Debug|x86.Build.0 = Debug|x86
 		{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
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Release|x86.ActiveCfg = Release|x86
+		{0FD91168-D8F5-4776-8D91-CB9B9C55AA1B}.Release|x86.Build.0 = Release|x86
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

NativeFileDialogSharp/NativeFileDialogSharp.csproj

@@ -15,6 +15,12 @@
 
     <ItemGroup>
         <Content Include="runtimes\**" PackagePath="runtimes" Visible="false" />
+        <Content Include="nfd.dll">
+            <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
+        </Content>
+        <Content Include="nfd_x86.dll">
+            <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
+        </Content>
     </ItemGroup>
 
 </Project>

NativeFileDialogSharp/NativeWrappers.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Runtime.InteropServices;
 using System.Text;
 using NativeFileDialogSharp.Native;
 
@@ -10,6 +11,32 @@ namespace NativeFileDialogSharp
     {
         private static readonly Encoder utf8encoder = Encoding.UTF8.GetEncoder();
 
+        private static readonly bool need32bit = Is32BitWindowsOnNetFramework();
+        
+        private static bool Is32BitWindowsOnNetFramework()
+        {
+            try
+            {
+                // we call a function that does nothing just to test if we can load it properly
+                NativeFileDialogSharp.Native.NativeFunctions.NFD_Dummy();
+                return false;
+            }
+            catch
+            {
+                // a call to a default library failed, let's attempt the other one
+                try
+                {
+                    NativeFileDialogSharp.Native.NativeFunctions32.NFD_Dummy();
+                    return true;
+                }
+                catch
+                {
+                    // both of them failed so we may as well default to the default one for predictability
+                    return false;
+                }
+            }
+        }
+
         private static unsafe byte[] ToUtf8(string s)
         {
             var byteCount = Encoding.UTF8.GetByteCount(s);
@@ -50,7 +77,10 @@ namespace NativeFileDialogSharp
             {
                 string path = null;
                 string errorMessage = null;
-                var result = NativeFunctions.NFD_OpenDialog(filterListNts, defaultPathNts, out IntPtr outPathIntPtr);
+                IntPtr outPathIntPtr;
+                var result = need32bit 
+                    ? NativeFunctions32.NFD_OpenDialog(filterListNts, defaultPathNts, out outPathIntPtr)
+                    : NativeFunctions.NFD_OpenDialog(filterListNts, defaultPathNts, out outPathIntPtr);
                 if (result == nfdresult_t.NFD_ERROR)
                 {
                     errorMessage = FromUtf8(NativeFunctions.NFD_GetError());
@@ -73,7 +103,10 @@ namespace NativeFileDialogSharp
             {
                 string path = null;
                 string errorMessage = null;
-                var result = NativeFunctions.NFD_SaveDialog(filterListNts, defaultPathNts, out IntPtr outPathIntPtr);
+                IntPtr outPathIntPtr;
+                var result = need32bit 
+                    ? NativeFunctions32.NFD_SaveDialog(filterListNts, defaultPathNts, out outPathIntPtr) 
+                    : NativeFunctions.NFD_SaveDialog(filterListNts, defaultPathNts, out outPathIntPtr);
                 if (result == nfdresult_t.NFD_ERROR)
                 {
                     errorMessage = FromUtf8(NativeFunctions.NFD_GetError());
@@ -95,7 +128,10 @@ namespace NativeFileDialogSharp
             {
                 string path = null;
                 string errorMessage = null;
-                var result = NativeFunctions.NFD_PickFolder(defaultPathNts, out IntPtr outPathIntPtr);
+                IntPtr outPathIntPtr;
+                var result = need32bit
+                    ? NativeFunctions32.NFD_PickFolder(defaultPathNts, out outPathIntPtr)
+                    : NativeFunctions.NFD_PickFolder(defaultPathNts, out outPathIntPtr);
                 if (result == nfdresult_t.NFD_ERROR)
                 {
                     errorMessage = FromUtf8(NativeFunctions.NFD_GetError());
@@ -119,7 +155,9 @@ namespace NativeFileDialogSharp
                 List<string> paths = null;
                 string errorMessage = null;
                 nfdpathset_t pathSet;
-                var result = NativeFunctions.NFD_OpenDialogMultiple(filterListNts, defaultPathNts, &pathSet);
+                var result = need32bit
+                    ? NativeFunctions32.NFD_OpenDialogMultiple(filterListNts, defaultPathNts, &pathSet)
+                    : NativeFunctions.NFD_OpenDialogMultiple(filterListNts, defaultPathNts, &pathSet);
                 if (result == nfdresult_t.NFD_ERROR)
                 {
                     errorMessage = FromUtf8(NativeFunctions.NFD_GetError());

NativeFileDialogSharpSandboxNetFramework/NativeFileDialogSharpSandboxNetFramework.csproj

@@ -53,9 +53,29 @@
     <ErrorReport>prompt</ErrorReport>
     <Prefer32Bit>true</Prefer32Bit>
   </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
+    <DebugSymbols>true</DebugSymbols>
+    <OutputPath>bin\x86\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <DebugType>full</DebugType>
+    <PlatformTarget>x86</PlatformTarget>
+    <LangVersion>7.3</LangVersion>
+    <ErrorReport>prompt</ErrorReport>
+    <Prefer32Bit>true</Prefer32Bit>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
+    <OutputPath>bin\x86\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <Optimize>true</Optimize>
+    <DebugType>pdbonly</DebugType>
+    <PlatformTarget>x86</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>
+      <HintPath>..\packages\NativeFileDialogSharp.0.5.0\lib\netstandard2.0\NativeFileDialogSharp.dll</HintPath>
     </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
@@ -74,5 +94,9 @@
     <None Include="App.config" />
     <None Include="packages.config" />
   </ItemGroup>
+  <ItemGroup>
+    <Content Include="nfd.dll" />
+    <Content Include="nfd_x86.dll" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

NativeFileDialogSharpSandboxNetFramework/packages.config

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Microsoft.NETCore.Platforms" version="6.0.1" targetFramework="net462" />
+  <package id="NativeFileDialogSharp" version="0.5.0" targetFramework="net462" />
-  <package id="NativeFileDialogSharp" version="0.4.4" targetFramework="net462" />
 </packages>