Use CsWin32

DepotDownloader/DepotDownloader.csproj

@@ -19,6 +19,10 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Windows.CsWin32" Version="0.3.106">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
     <PackageReference Include="protobuf-net" Version="3.2.30" />
     <PackageReference Include="QRCoder" Version="1.6.0" />
     <PackageReference Include="SteamKit2" Version="3.0.0-Beta.2" />

DepotDownloader/NativeMethods.txt

@@ -0,0 +1,2 @@
+GetConsoleProcessList
+MessageBox

DepotDownloader/PlatformUtilities.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
 
 namespace DepotDownloader
 {
@@ -146,36 +147,24 @@ namespace DepotDownloader
             }
         }
 
-        #region WIN32_CONSOLE_STUFF
-        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
-        [DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
-        static extern uint GetConsoleProcessList(uint[] processList, uint processCount);
-
-        [DllImport("user32.dll", SetLastError = true, ExactSpelling = true, CharSet = CharSet.Unicode)]
-        [DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
-        static extern int MessageBoxW(IntPtr hWnd, string text, string caption, uint type);
-
-        const uint MB_OK = 0x0;
-        const uint MB_ICONWARNING = 0x30;
-
+        [SupportedOSPlatform("windows5.0")]
         public static void VerifyConsoleLaunch()
         {
             // Reference: https://devblogs.microsoft.com/oldnewthing/20160125-00/?p=92922
             var processList = new uint[2];
-            var processCount = GetConsoleProcessList(processList, (uint)processList.Length);
+            var processCount = Windows.Win32.PInvoke.GetConsoleProcessList(processList);
 
             if (processCount != 1)
             {
                 return;
             }
 
-            _ = MessageBoxW(
-                IntPtr.Zero,
+            _ = Windows.Win32.PInvoke.MessageBox(
+                Windows.Win32.Foundation.HWND.Null,
                 "Depot Downloader is a console application; there is no GUI.\n\nIf you do not pass any command line parameters, it prints usage info and exits.\n\nYou must use this from a terminal/console.",
-                "DepotDownloader",
-                MB_OK | MB_ICONWARNING
+                "Depot Downloader",
+                Windows.Win32.UI.WindowsAndMessaging.MESSAGEBOX_STYLE.MB_OK | Windows.Win32.UI.WindowsAndMessaging.MESSAGEBOX_STYLE.MB_ICONWARNING
             );
         }
-        #endregion
     }
 }