Replace `DllImport` usage with `LibraryImport` (#4084)

* Replace usage of `DllImport` with `LibraryImport`

* Mark methods as `partial`

* Marshalling

* More `partial` & marshalling

* More `partial` and marshalling

* More partial and marshalling

* Update GdiPlusHelper to LibraryImport

* Unicorn

* More Partial

* Marshal

* Specify EntryPoint

* Specify EntryPoint

* Change GlobalMemoryStatusEx to LibraryImport

* Change RegisterClassEx to LibraryImport

* Define EntryPoints

* Update Ryujinx.Ava/Ui/Controls/Win32NativeInterop.cs

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>

* Update Ryujinx.Graphics.Nvdec.FFmpeg/Native/FFmpegApi.cs

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>

* Move return mashal

* Remove calling convention specification

* Remove calling conventions

* Update Ryujinx.Common/SystemInfo/WindowsSystemInfo.cs

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>

* Update Ryujinx/Modules/Updater/Updater.cs

Co-authored-by: Mary-nyan <thog@protonmail.com>

* Update Ryujinx.Ava/Modules/Updater/Updater.cs

Co-authored-by: Mary-nyan <thog@protonmail.com>

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>
Co-authored-by: Mary-nyan <thog@protonmail.com>

2 files changed, 28 insertions, 32 deletions

diff --git a/Ryujinx.Ava/Ui/Controls/EmbeddedWindow.cs b/Ryujinx.Ava/Ui/Controls/EmbeddedWindow.cs
index 26007591..05b2cc5b 100644
--- a/Ryujinx.Ava/Ui/Controls/EmbeddedWindow.cs
+++ b/Ryujinx.Ava/Ui/Controls/EmbeddedWindow.cs
@@ -125,9 +125,9 @@ namespace Ryujinx.Ava.Ui.Controls
             {
                 cbSize = Marshal.SizeOf<WNDCLASSEX>(),
                 hInstance = GetModuleHandle(null),
-                lpfnWndProc = _wndProcDelegate,
+                lpfnWndProc = Marshal.GetFunctionPointerForDelegate(_wndProcDelegate),
                 style = ClassStyles.CS_OWNDC,
-                lpszClassName = _className,
+                lpszClassName = Marshal.StringToHGlobalUni(_className),
                 hCursor = LoadCursor(IntPtr.Zero, (IntPtr)Cursors.IDC_ARROW)
             };
 
@@ -148,7 +148,9 @@ namespace Ryujinx.Ava.Ui.Controls
                 IntPtr.Zero);
 
             WindowHandle = handle;
-
+            
+            Marshal.FreeHGlobal(wndClassEx.lpszClassName);
+            
             return new PlatformHandle(WindowHandle, "HWND");
         }
 
diff --git a/Ryujinx.Ava/Ui/Controls/Win32NativeInterop.cs b/Ryujinx.Ava/Ui/Controls/Win32NativeInterop.cs
index 124536d9..81e2fee9 100644
--- a/Ryujinx.Ava/Ui/Controls/Win32NativeInterop.cs
+++ b/Ryujinx.Ava/Ui/Controls/Win32NativeInterop.cs
@@ -5,7 +5,7 @@ using System.Runtime.Versioning;
 namespace Ryujinx.Ava.Ui.Controls
 {
     [SupportedOSPlatform("windows")]
-    internal class Win32NativeInterop
+    internal partial class Win32NativeInterop
     {
         [Flags]
         public enum ClassStyles : uint
@@ -48,58 +48,52 @@ namespace Ryujinx.Ava.Ui.Controls
         [UnmanagedFunctionPointer(CallingConvention.Winapi)]
         internal delegate IntPtr WindowProc(IntPtr hWnd, WindowsMessages msg, IntPtr wParam, IntPtr lParam);
 
-        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
+        [StructLayout(LayoutKind.Sequential)]
         public struct WNDCLASSEX
         {
             public int cbSize;
             public ClassStyles style;
-            [MarshalAs(UnmanagedType.FunctionPtr)]
-            public WindowProc lpfnWndProc; // not WndProc
+            public IntPtr lpfnWndProc; // not WndProc
             public int cbClsExtra;
             public int cbWndExtra;
             public IntPtr hInstance;
             public IntPtr hIcon;
             public IntPtr hCursor;
             public IntPtr hbrBackground;
-            [MarshalAs(UnmanagedType.LPWStr)]
-            public string lpszMenuName;
-            [MarshalAs(UnmanagedType.LPWStr)]
-            public string lpszClassName;
+            public IntPtr lpszMenuName;
+            public IntPtr lpszClassName;
             public IntPtr hIconSm;
 
-            public static WNDCLASSEX Create()
+            public WNDCLASSEX()
             {
-                return new WNDCLASSEX
-                {
-                    cbSize = Marshal.SizeOf<WNDCLASSEX>()
-                };
+                cbSize = Marshal.SizeOf<WNDCLASSEX>();
             }
         }
 
-        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
-        public static extern ushort RegisterClassEx(ref WNDCLASSEX param);
+        [LibraryImport("user32.dll", SetLastError = true, EntryPoint = "RegisterClassExW")]
+        public static partial ushort RegisterClassEx(ref WNDCLASSEX param);
 
-        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
-        public static extern short UnregisterClass([MarshalAs(UnmanagedType.LPWStr)] string lpClassName, IntPtr instance);
+        [LibraryImport("user32.dll", SetLastError = true, EntryPoint = "UnregisterClassW")]
+        public static partial short UnregisterClass([MarshalAs(UnmanagedType.LPWStr)] string lpClassName, IntPtr instance);
 
-        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
-        public static extern IntPtr DefWindowProc(IntPtr hWnd, WindowsMessages msg, IntPtr wParam, IntPtr lParam);
+        [LibraryImport("user32.dll", EntryPoint = "DefWindowProcW")]
+        public static partial IntPtr DefWindowProc(IntPtr hWnd, WindowsMessages msg, IntPtr wParam, IntPtr lParam);
 
-        [DllImport("kernel32.dll")]
-        public static extern IntPtr GetModuleHandle(string lpModuleName);
+        [LibraryImport("kernel32.dll", EntryPoint = "GetModuleHandleA")]
+        public static partial IntPtr GetModuleHandle([MarshalAs(UnmanagedType.LPStr)] string lpModuleName);
 
-        [DllImport("user32.dll", SetLastError = true)]
+        [LibraryImport("user32.dll", SetLastError = true)]
         [return: MarshalAs(UnmanagedType.Bool)]
-        public static extern bool DestroyWindow(IntPtr hwnd);
+        public static partial bool DestroyWindow(IntPtr hwnd);
 
-        [DllImport("user32.dll", SetLastError = true)]
-        public static extern IntPtr LoadCursor(IntPtr hInstance, IntPtr lpCursorName);
+        [LibraryImport("user32.dll", SetLastError = true, EntryPoint = "LoadCursorA")]
+        public static partial IntPtr LoadCursor(IntPtr hInstance, IntPtr lpCursorName);
 
-        [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
-        public static extern IntPtr CreateWindowEx(
+        [LibraryImport("user32.dll", SetLastError = true, EntryPoint = "CreateWindowExW")]
+        public static partial IntPtr CreateWindowEx(
            uint dwExStyle,
-           string lpClassName,
-           string lpWindowName,
+           [MarshalAs(UnmanagedType.LPWStr)] string lpClassName,
+           [MarshalAs(UnmanagedType.LPWStr)] string lpWindowName,
            WindowStyles dwStyle,
            int x,
            int y,