WPF 使用 Silk.NET 進行 DirectX 渲染入門

本文告訴大家如何使用 dotnet 基金會新開源的 Silk.NET 庫調用 DirectX 進行渲染的方法。此庫是對 DirectX 的底層基礎封裝，用上了 dotnet 和 C# 的各個新特性，相對來說基礎性能較好，也許后續可以考慮作為 SharpDx 的代替

本文將告訴大家如何使用 Silk.NET 創建 DirectX 的各個對象，進行初始化邏輯，再對接 Direct2D 進行界面繪制。當前是 2021.12.23 此時 Silk.NET 還沒有完成 Direct2D 的封裝，為了方便演示，本文使用了 SharpDx 的 D2D 代替

本文非新手友好，如果是剛接觸 DirectX 那我推薦先閱讀 WPF 使用 SharpDx 渲染博客導航

當前 SharpDx 已不維護，我正在找代替的項目，詳細請看 SharpDx 的代替項目

剛好找到了 dotnet 基金會下的 Silk.NET 庫，此庫是新寫的，用上了很多 dotnet 和 C# 的新特性，例如通過 COM 調用 DirectX 的實現邏輯是通過了 delegate* unmanaged 新特性，這是 C# 9 的新特性，請看 Function pointers - C# 9.0 draft specifications Microsoft Docs

代碼的寫法如下

        public ID3D11Device
        (
            void** lpVtbl = null
        ) : this()
        {
            if (lpVtbl is not null)
            {
                LpVtbl = lpVtbl;
            }
        }

        public void** LpVtbl;

        public readonly unsafe int QueryInterface(Guid* riid, void** ppvObject)
        {
            var @this = (ID3D11Device*) Unsafe.AsPointer(ref Unsafe.AsRef(in this));
            int ret = default;
            ret = ((delegate* unmanaged[Cdecl]<ID3D11Device*, Guid*, void**, int>)LpVtbl[0])(@this, riid, ppvObject);
            return ret;
        }

通過以上的代碼，特別是 ((delegate* unmanaged[Cdecl]<ID3D12Device*, Guid*, void**, int>)LpVtbl[0])(@this, riid, ppvObject); 這句如此復雜的代碼，即可減少 COM 默認 dotnet 封裝的 RCW 封裝層的封送損耗。當然了，這部分不是本文的重點，細節請看 Runtime Callable Wrapper Microsoft Docs

大家只需要知道，此庫的實現里面，可以很大減少調用 COM 時的額外損耗。但這也帶來了一點坑，例如調用方也只能采用不安全代碼調用，寫法也有點詭異

根據 Surface sharing between Windows graphics APIs - Win32 apps 文檔，為了在 WPF 的 D3DImage 上進行 D2D 繪制，就需要通過 D3D11 進行轉接，好在此轉接也只是指針的傳輸而已，基本沒有啥性能損耗。為了在 WPF 上使用到 D2D 就需要執行如下步驟：

• 創建 D3D11 設備
• 通過 DXGI 關聯 D2D 設備
• 創建 D3D9 設備

如官方文檔的轉換圖

使用 DirectX 時，初始化參數的代碼將會特別多。由於 Silk.NET 只是對 DirectX 的底層封裝，沒有細節隱藏，也就是說使用過程的復雜度也會特別多

在開始之前，先准備一個空 WPF 項目，基於 dotnet 6 框架。安裝好如下庫，可編輯 csproj 文件，修改為如下代碼

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net6.0-windows</TargetFramework>
    <Nullable>enable</Nullable>
    <UseWPF>true</UseWPF>
    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="SharpDX.Direct2D1" Version="4.2.0" />
    <PackageReference Include="Silk.NET.Direct3D11" Version="2.11.0" />
    <PackageReference Include="Silk.NET.Direct3D9" Version="2.11.0" />
    <PackageReference Include="Silk.NET.DXGI" Version="2.11.0" />
  </ItemGroup>

</Project>

以上代碼關鍵在於 AllowUnsafeBlocks 需要開啟，用於開啟不安全代碼給 Silk.NET 調用代碼所使用。當前 Silk.NET 還沒有完成 D2D 封裝，本文將使用 SharpDX.Direct2D1 庫輔助編寫 D2D 的代碼

在 XAML 界面添加 D3DImage 如下面代碼

<Window x:Class="RawluharkewalQeaninanel.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:RawluharkewalQeaninanel"
        xmlns:interop="clr-namespace:System.Windows.Interop;assembly=PresentationCore"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Image>
            <Image.Source>
                <interop:D3DImage x:Name="D3DImage"></interop:D3DImage>
            </Image.Source>
        </Image>
    </Grid>
</Window>

為了等待窗口等初始化完成，將在 Loaded 時進行實際的初始化代碼

        public MainWindow()
        {
            InitializeComponent();

            Loaded += MainWindow_Loaded;
        }

在 MainWindow_Loaded 上添加本文的關鍵邏輯

按照順序，先創建 D3D11 設備和初始化。開始前，考慮到命名空間十分復雜，為了方便理解，先定義引用，如以下代碼

using Silk.NET.Core.Native;

using D3D11 = Silk.NET.Direct3D11;
using D3D9 = Silk.NET.Direct3D9;
using DXGI = Silk.NET.DXGI;
using D2D = SharpDX.Direct2D1;
using SharpDXDXGI = SharpDX.DXGI;
using SharpDXMathematics = SharpDX.Mathematics.Interop;

雖然加上此命名空間引用會讓代碼寫的時候，稍微復雜一點，但好在清晰

定義完成之后，開始創建 D3D11 設備。 創建過程中，需要先設置參數，代碼如下

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            // 根據 [Surface sharing between Windows graphics APIs - Win32 apps](https://docs.microsoft.com/en-us/windows/win32/direct3darticles/surface-sharing-between-windows-graphics-apis?WT.mc_id=WD-MVP-5003260 ) 文檔

            var width = ImageWidth;
            var height = ImageHeight;

            // 2021.12.23 不能在 x86 下運行，會炸掉。參閱 https://github.com/dotnet/Silk.NET/issues/731

            var texture2DDesc = new D3D11.Texture2DDesc()
            {
                BindFlags = (uint) (D3D11.BindFlag.BindRenderTarget | D3D11.BindFlag.BindShaderResource),
                Format = DXGI.Format.FormatB8G8R8A8Unorm, // 最好使用此格式，否則還需要后續轉換
                Width = (uint) width,
                Height = (uint) height,
                MipLevels = 1,
                SampleDesc = new DXGI.SampleDesc(1, 0),
                Usage = D3D11.Usage.UsageDefault,
                MiscFlags = (uint) D3D11.ResourceMiscFlag.ResourceMiscShared,
                // The D3D11_RESOURCE_MISC_FLAG cannot be used when creating resources with D3D11_CPU_ACCESS flags.
                CPUAccessFlags = 0, //(uint) D3D11.CpuAccessFlag.None,
                ArraySize = 1
            };

            // 忽略代碼
        }
        private int ImageWidth => (int) ActualWidth;
        private int ImageHeight => (int) ActualHeight;

需要特別說明以上代碼的一個注釋，當前 Silk.NET 對 X86 的支持較弱，調試模式下運行將會炸掉應用，非調試模式下沒啥問題。其原因是 Silk.NET 對於 COM 封裝在定義上是不對的，我給官方報告了此問題，請看 https://github.com/dotnet/Silk.NET/issues/731

問題的原因是在 Silk.NET 里面，定義對 DirectX 的調用，使用的是 Cdecl 方式調用，然而在 DirectX 的定義里，需要采用 Stdcall 來調用才是正確的。此行為將在 X86 下導致調用棧的內容不對，本應該清理的內容沒有正確清理。這部分細節請參閱 stdcall Microsoft Docs 和 cdecl Microsoft Docs 官方文檔

創建參數里，為了方便在 WPF 里使用，要求最好使用 FormatB8G8R8A8Unorm 格式。以上參數差不多是固定寫法，各個參數的細節請看 DirectX 官方文檔

接下來通過 D3D11 類型的 GetApi 方法獲取 D3D11 對象，此對象的獲取是 Silk.NET 的封裝，不屬於 DirectX 的內容

            D3D11.D3D11 d3D11 = D3D11.D3D11.GetApi();

因為 Silk.NET 的封裝特別底層，需要開啟不安全代碼才能創建對象，為了方便編寫代碼，將在 class 上加上 unsafe 讓此類的所有代碼在使用不安全代碼，不需要再加上 unsafe 即可使用

    public unsafe partial class MainWindow : Window
    {
    }

創建 D3D11 設備的代碼如下

            D3D11.ID3D11Device* pD3D11Device;
            D3D11.ID3D11DeviceContext* pD3D11DeviceContext;
            D3DFeatureLevel pD3DFeatureLevel = default;

            var hr = d3D11.CreateDevice((DXGI.IDXGIAdapter*) IntPtr.Zero, D3DDriverType.D3DDriverTypeHardware,
                Software: 0,
                Flags: (uint) D3D11.CreateDeviceFlag.CreateDeviceBgraSupport,
                (D3DFeatureLevel*) IntPtr.Zero,
                FeatureLevels: 0, // D3DFeatureLevel 的長度
                SDKVersion: 7,
                (D3D11.ID3D11Device**) &pD3D11Device, // 參閱 [C# 從零開始寫 SharpDx 應用 聊聊功能等級](https://blog.lindexi.com/post/C-%E4%BB%8E%E9%9B%B6%E5%BC%80%E5%A7%8B%E5%86%99-SharpDx-%E5%BA%94%E7%94%A8-%E8%81%8A%E8%81%8A%E5%8A%9F%E8%83%BD%E7%AD%89%E7%BA%A7.html )
                ref pD3DFeatureLevel,
                (D3D11.ID3D11DeviceContext**) &pD3D11DeviceContext
            );
            SilkMarshal.ThrowHResult(hr);

可以看到代碼里面大量用到不安全代碼

在創建完成了 D3D11 設備之后，即可開始創建 Texture 對象。咱的步驟是創建出 Texture 用來共享和給 D2D 繪制用，但 D2D 繪制在的是 Texture 的 IDXGISurface 平面上

創建 Texture2D 代碼如下

            D3D11.ID3D11Texture2D* pD3D11Texture2D;
            hr = pD3D11Device->CreateTexture2D(ref texture2DDesc, (D3D11.SubresourceData*) IntPtr.Zero, &pD3D11Texture2D);
            SilkMarshal.ThrowHResult(hr);

此 ID3D11Texture2D 就是作為后續 D2D 繪制的 IDXGISurface 對象

            var renderTarget = pD3D11Texture2D;
            DXGI.IDXGISurface* pDXGISurface;
            var dxgiSurfaceGuid = DXGI.IDXGISurface.Guid;
            renderTarget->QueryInterface(ref dxgiSurfaceGuid, (void**) &pDXGISurface);

接下來部分就是 SharpDx 的啦，當前 Silk.NET 還沒有封裝好 D2D 部分，於是這里就和 WPF 使用 SharpDX 博客的方法差不多，只是創建 SharpDX 的 Surface 代碼稍微修改而已

            var surface = new SharpDXDXGI.Surface(new IntPtr((void*) pDXGISurface));

其他邏輯如下

            var d2DFactory = new D2D.Factory();

            var renderTargetProperties =
                new D2D.RenderTargetProperties(new D2D.PixelFormat(SharpDXDXGI.Format.Unknown, D2D.AlphaMode.Premultiplied));
            _d2DRenderTarget = new D2D.RenderTarget(d2DFactory, surface, renderTargetProperties);

        private D2D.RenderTarget _d2DRenderTarget;

拿到了 D2D.RenderTarget 就可以進行 D2D 繪制。但是在開始前，還需要關聯到 WPF 的 D3DImage 才能渲染。為了關聯 D3DImage 就需要繼續創建 D3D9 設備，如下面代碼，調用 SetRenderTarget 將 D3D11 創建的 ID3D11Texture2D 作為 D3D9 的共享紋理，從而讓 D2D 的內容可以在 D3DImage 上使用

            SetRenderTarget(renderTarget);

在 SetRenderTarget 的代碼是從 ID3D11Texture2D 轉到 IDirect3DSurface9 上，將 IDirect3DSurface9 作為 D3DImage 的 BackBuffer 給 WPF 使用

        private void SetRenderTarget(D3D11.ID3D11Texture2D* target)
        {
        }

從 ID3D11Texture2D 轉到 IDirect3DSurface9 上有如下步驟：

• 獲取共享指針
• 創建 D3D9 設備
• 通過 D3D9 設備，使用共享指針創建紋理，通過紋理獲取平面

獲取共享指針是為了讓 D3D9 的紋理共享 D3D11 的資源，獲取代碼如下

            DXGI.IDXGIResource* pDXGIResource;
            var dxgiResourceGuid = DXGI.IDXGIResource.Guid;
            target->QueryInterface(ref dxgiResourceGuid, (void**) &pDXGIResource);

            void* sharedHandle;
            var hr = pDXGIResource->GetSharedHandle(&sharedHandle);
            SilkMarshal.ThrowHResult(hr);

創建 D3D9 之前，需要使用 Silk.NET 的 D3D9 類的 GetApi 對象獲取 D3D9 對象。這是 Silk.NET 的設計，可以看到此庫很多類型都有 GetApi 方法

            var d3d9 = D3D9.D3D9.GetApi();

創建 D3D9 設備之前，需要先創建 IDirect3D9Ex 對象

            D3D9.IDirect3D9Ex* pDirect3D9Ex;
            hr = d3d9.Direct3DCreate9Ex(SDKVersion: 32, &pDirect3D9Ex);
            SilkMarshal.ThrowHResult(hr);
            var d3DContext = pDirect3D9Ex;

創建 D3D9 設備之前，也需要初始化參數，有一些參數需要和 D3D11 創建的參數相同，需要先獲取 D3D11 的參數

            D3D11.Texture2DDesc texture2DDescription = default;
            target->GetDesc(ref texture2DDescription);

初始化創建 D3D9 的創建參數

            var presentParameters = new D3D9.PresentParameters()
            {
                Windowed = 1,// true
                SwapEffect = D3D9.Swapeffect.SwapeffectDiscard,
                HDeviceWindow = GetDesktopWindow(),
                PresentationInterval = D3D9.D3D9.PresentIntervalDefault,
            };

            // 設置使用多線程方式，這樣的性能才足夠
            uint createFlags = D3D9.D3D9.CreateHardwareVertexprocessing | D3D9.D3D9.CreateMultithreaded | D3D9.D3D9.CreateFpuPreserve;

        [DllImport("user32.dll", SetLastError = false)]
        public static extern IntPtr GetDesktopWindow();

拿到創建參數，創建 D3D9 設備

            D3D9.IDirect3DDevice9Ex* pDirect3DDevice9Ex;
            hr = d3DContext->CreateDeviceEx(Adapter: 0, 
                DeviceType: D3D9.Devtype.DevtypeHal,// 使用硬件渲染
                hFocusWindow: IntPtr.Zero, 
                createFlags,
                ref presentParameters, 
                pFullscreenDisplayMode: (D3D9.Displaymodeex*) IntPtr.Zero, 
                &pDirect3DDevice9Ex);
            SilkMarshal.ThrowHResult(hr);

            var d3DDevice = pDirect3DDevice9Ex;

拿到 D3D9 設備，開始創建紋理

            D3D9.IDirect3DTexture9* pDirect3DTexture9;
            hr = d3DDevice->CreateTexture(texture2DDescription.Width, texture2DDescription.Height, Levels: 1,
                D3D9.D3D9.UsageRendertarget, 
                D3D9.Format.FmtA8R8G8B8, // 這是必須要求的顏色，不能使用其他顏色
                D3D9.Pool.PoolDefault, 
                &pDirect3DTexture9,
                &sharedHandle);
            SilkMarshal.ThrowHResult(hr);
            _renderTarget = pDirect3DTexture9;

        private D3D9.IDirect3DTexture9* _renderTarget;

紋理有要求顏色格式，也要求尺寸和 D3D11 的相同

通過紋理可以拿到 IDirect3DSurface9 對象

            D3D9.IDirect3DSurface9* pDirect3DSurface9;
            _renderTarget->GetSurfaceLevel(0, &pDirect3DSurface9);
            _pDirect3DSurface9 = pDirect3DSurface9;

將 IDirect3DSurface9 作為 D3DImage 的 BackBuffer 即可完成初始化

            D3DImage.Lock();
            D3DImage.SetBackBuffer(D3DResourceType.IDirect3DSurface9, new IntPtr(pDirect3DSurface9));
            D3DImage.Unlock();

在 MainWindow_Loaded 設置將一個視圖數組綁定到管道的光柵化階段

            var viewport = new D3D11.Viewport(0, 0, width, height, 0, 1);
            pD3D11DeviceContext->RSSetViewports(NumViewports: 1, ref viewport);

開始測試 D2D 的渲染，通過測試 D2D 即可了解是否創建初始化成功。在 WPF 的 CompositionTarget 的 Rendering 進行 D2D 繪制

            CompositionTarget.Rendering += CompositionTarget_Rendering;

        private void CompositionTarget_Rendering(object? sender, EventArgs e)
        {
            _d2DRenderTarget.BeginDraw();

            OnRender(_d2DRenderTarget);

            _d2DRenderTarget.EndDraw();

            D3DImage.Lock();

            D3DImage.AddDirtyRect(new Int32Rect(0, 0, D3DImage.PixelWidth, D3DImage.PixelHeight));

            D3DImage.Unlock();
        }

在 OnRender 方法加上 D2D 的繪制內容，這就是測試邏輯，請根據自己的需求編寫

        private void OnRender(D2D.RenderTarget renderTarget)
        {
            var brush = new D2D.SolidColorBrush(_d2DRenderTarget, new SharpDXMathematics.RawColor4(1, 0, 0, 1));

            renderTarget.Clear(null);

            renderTarget.DrawRectangle(new SharpDXMathematics.RawRectangleF(_x, _y, _x + 10, _y + 10), brush);

            _x = _x + _dx;
            _y = _y + _dy;
            if (_x >= ActualWidth - 10 || _x <= 0)
            {
                _dx = -_dx;
            }

            if (_y >= ActualHeight - 10 || _y <= 0)
            {
                _dy = -_dy;
            }
        }

        private float _x;
        private float _y;
        private float _dx = 1;
        private float _dy = 1;

按照微軟官方的推薦，在 CompositionTarget_Rendering 里，如果進行 DirectX 的邏輯，需要判斷是否進入了多次，但本文這里只是測試邏輯，忽略官方給出的邏輯

運行代碼即可看到界面上有一個矩形顯示

也許后續我會封裝一個 Silk.NET 的 DirectX 給 WPF 使用的控件

#nullable disable

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;

using Silk.NET.Core.Native;

using D3D11 = Silk.NET.Direct3D11;
using D3D9 = Silk.NET.Direct3D9;
using DXGI = Silk.NET.DXGI;
using D2D = SharpDX.Direct2D1;
using SharpDXDXGI = SharpDX.DXGI;
using SharpDXMathematics = SharpDX.Mathematics.Interop;

namespace RawluharkewalQeaninanel
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public unsafe partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            // 根據 [Surface sharing between Windows graphics APIs - Win32 apps](https://docs.microsoft.com/en-us/windows/win32/direct3darticles/surface-sharing-between-windows-graphics-apis?WT.mc_id=WD-MVP-5003260 ) 文檔

            var width = ImageWidth;
            var height = ImageHeight;

            // 2021.12.23 不能在 x86 下運行，會炸掉。參閱 https://github.com/dotnet/Silk.NET/issues/731

            var texture2DDesc = new D3D11.Texture2DDesc()
            {
                BindFlags = (uint) (D3D11.BindFlag.BindRenderTarget | D3D11.BindFlag.BindShaderResource),
                Format = DXGI.Format.FormatB8G8R8A8Unorm, // 最好使用此格式，否則還需要后續轉換
                Width = (uint) width,
                Height = (uint) height,
                MipLevels = 1,
                SampleDesc = new DXGI.SampleDesc(1, 0),
                Usage = D3D11.Usage.UsageDefault,
                MiscFlags = (uint) D3D11.ResourceMiscFlag.ResourceMiscShared,
                // The D3D11_RESOURCE_MISC_FLAG cannot be used when creating resources with D3D11_CPU_ACCESS flags.
                CPUAccessFlags = 0, //(uint) D3D11.CpuAccessFlag.None,
                ArraySize = 1
            };

            D3D11.ID3D11Device* pD3D11Device;
            D3D11.ID3D11DeviceContext* pD3D11DeviceContext;
            D3DFeatureLevel pD3DFeatureLevel = default;
            D3D11.D3D11 d3D11 = D3D11.D3D11.GetApi();

            var hr = d3D11.CreateDevice((DXGI.IDXGIAdapter*) IntPtr.Zero, D3DDriverType.D3DDriverTypeHardware,
                Software: 0,
                Flags: (uint) D3D11.CreateDeviceFlag.CreateDeviceBgraSupport,
                (D3DFeatureLevel*) IntPtr.Zero,
                FeatureLevels: 0, // D3DFeatureLevel 的長度
                SDKVersion: 7,
                (D3D11.ID3D11Device**) &pD3D11Device, // 參閱 [C# 從零開始寫 SharpDx 應用 聊聊功能等級](https://blog.lindexi.com/post/C-%E4%BB%8E%E9%9B%B6%E5%BC%80%E5%A7%8B%E5%86%99-SharpDx-%E5%BA%94%E7%94%A8-%E8%81%8A%E8%81%8A%E5%8A%9F%E8%83%BD%E7%AD%89%E7%BA%A7.html )
                ref pD3DFeatureLevel,
                (D3D11.ID3D11DeviceContext**) &pD3D11DeviceContext
            );
            SilkMarshal.ThrowHResult(hr);

            Debugger.Launch();
            Debugger.Break();

            _pD3D11Device = pD3D11Device;
            _pD3D11DeviceContext = pD3D11DeviceContext;

            D3D11.ID3D11Texture2D* pD3D11Texture2D;
            hr = pD3D11Device->CreateTexture2D(ref texture2DDesc, (D3D11.SubresourceData*) IntPtr.Zero, &pD3D11Texture2D);
            SilkMarshal.ThrowHResult(hr);

            var renderTarget = pD3D11Texture2D;
            _pD3D11Texture2D = pD3D11Texture2D;

            DXGI.IDXGISurface* pDXGISurface;
            var dxgiSurfaceGuid = DXGI.IDXGISurface.Guid;
            renderTarget->QueryInterface(ref dxgiSurfaceGuid, (void**) &pDXGISurface);
            _pDXGISurface = pDXGISurface;

            var d2DFactory = new D2D.Factory();

            var renderTargetProperties =
                new D2D.RenderTargetProperties(new D2D.PixelFormat(SharpDXDXGI.Format.Unknown, D2D.AlphaMode.Premultiplied));
            var surface = new SharpDXDXGI.Surface(new IntPtr((void*) pDXGISurface));
            _d2DRenderTarget = new D2D.RenderTarget(d2DFactory, surface, renderTargetProperties);

            SetRenderTarget(renderTarget);

            var viewport = new D3D11.Viewport(0, 0, width, height, 0, 1);
            pD3D11DeviceContext->RSSetViewports(NumViewports: 1, ref viewport);

            CompositionTarget.Rendering += CompositionTarget_Rendering;
        }

        private void CompositionTarget_Rendering(object? sender, EventArgs e)
        {
            _d2DRenderTarget.BeginDraw();

            OnRender(_d2DRenderTarget);

            _d2DRenderTarget.EndDraw();

            D3DImage.Lock();

            D3DImage.AddDirtyRect(new Int32Rect(0, 0, D3DImage.PixelWidth, D3DImage.PixelHeight));

            D3DImage.Unlock();
        }

        private void OnRender(D2D.RenderTarget renderTarget)
        {
            var brush = new D2D.SolidColorBrush(_d2DRenderTarget, new SharpDXMathematics.RawColor4(1, 0, 0, 1));

            renderTarget.Clear(null);

            renderTarget.DrawRectangle(new SharpDXMathematics.RawRectangleF(_x, _y, _x + 10, _y + 10), brush);

            _x = _x + _dx;
            _y = _y + _dy;
            if (_x >= ActualWidth - 10 || _x <= 0)
            {
                _dx = -_dx;
            }

            if (_y >= ActualHeight - 10 || _y <= 0)
            {
                _dy = -_dy;
            }
        }

        private float _x;
        private float _y;
        private float _dx = 1;
        private float _dy = 1;

        private void SetRenderTarget(D3D11.ID3D11Texture2D* target)
        {
            DXGI.IDXGIResource* pDXGIResource;
            var dxgiResourceGuid = DXGI.IDXGIResource.Guid;
            target->QueryInterface(ref dxgiResourceGuid, (void**) &pDXGIResource);

            D3D11.Texture2DDesc texture2DDescription = default;
            target->GetDesc(ref texture2DDescription);

            void* sharedHandle;
            var hr = pDXGIResource->GetSharedHandle(&sharedHandle);
            SilkMarshal.ThrowHResult(hr);

            var d3d9 = D3D9.D3D9.GetApi();
            D3D9.IDirect3D9Ex* pDirect3D9Ex;
            hr = d3d9.Direct3DCreate9Ex(SDKVersion: 32, &pDirect3D9Ex);
            SilkMarshal.ThrowHResult(hr);
            var d3DContext = pDirect3D9Ex;
            _pDirect3D9Ex = pDirect3D9Ex;

            var presentParameters = new D3D9.PresentParameters()
            {
                Windowed = 1,// true
                SwapEffect = D3D9.Swapeffect.SwapeffectDiscard,
                HDeviceWindow = GetDesktopWindow(),
                PresentationInterval = D3D9.D3D9.PresentIntervalDefault,
            };

            // 設置使用多線程方式，這樣的性能才足夠
            uint createFlags = D3D9.D3D9.CreateHardwareVertexprocessing | D3D9.D3D9.CreateMultithreaded | D3D9.D3D9.CreateFpuPreserve;

            D3D9.IDirect3DDevice9Ex* pDirect3DDevice9Ex;
            hr = d3DContext->CreateDeviceEx(Adapter: 0, 
                DeviceType: D3D9.Devtype.DevtypeHal,// 使用硬件渲染
                hFocusWindow: IntPtr.Zero, 
                createFlags,
                ref presentParameters, 
                pFullscreenDisplayMode: (D3D9.Displaymodeex*) IntPtr.Zero, 
                &pDirect3DDevice9Ex);
            SilkMarshal.ThrowHResult(hr);

            var d3DDevice = pDirect3DDevice9Ex;

            D3D9.IDirect3DTexture9* pDirect3DTexture9;
            hr = d3DDevice->CreateTexture(texture2DDescription.Width, texture2DDescription.Height, Levels: 1,
                D3D9.D3D9.UsageRendertarget, 
                D3D9.Format.FmtA8R8G8B8, // 這是必須要求的顏色，不能使用其他顏色
                D3D9.Pool.PoolDefault, 
                &pDirect3DTexture9,
                &sharedHandle);
            SilkMarshal.ThrowHResult(hr);
            _renderTarget = pDirect3DTexture9;

            D3D9.IDirect3DSurface9* pDirect3DSurface9;
            _renderTarget->GetSurfaceLevel(0, &pDirect3DSurface9);
            _pDirect3DSurface9 = pDirect3DSurface9;

            D3DImage.Lock();
            D3DImage.SetBackBuffer(D3DResourceType.IDirect3DSurface9, new IntPtr(pDirect3DSurface9));
            D3DImage.Unlock();
        }

        // 這些字段的另一個作用是防止回收
        private D2D.RenderTarget _d2DRenderTarget;

        private D3D11.ID3D11Device* _pD3D11Device;
        private D3D11.ID3D11DeviceContext* _pD3D11DeviceContext;
        private D3D11.ID3D11Texture2D* _pD3D11Texture2D;
        private DXGI.IDXGISurface* _pDXGISurface;

        private D3D9.IDirect3D9Ex* _pDirect3D9Ex;
        private D3D9.IDirect3DTexture9* PDirect3DTexture9 => _renderTarget;
        private D3D9.IDirect3DTexture9* _renderTarget;
        private D3D9.IDirect3DSurface9* _pDirect3DSurface9;

        private int ImageWidth => (int) ActualWidth;
        private int ImageHeight => (int) ActualHeight;

        [DllImport("user32.dll", SetLastError = false)]
        public static extern IntPtr GetDesktopWindow();
    }
}

本文所有代碼放在github 和 gitee 歡迎訪問

可以通過如下方式獲取本文的源代碼，先創建一個空文件夾，接着使用命令行 cd 命令進入此空文件夾，在命令行里面輸入以下代碼，即可獲取到本文的代碼

git init
git remote add origin https://gitee.com/lindexi/lindexi_gd.git
git pull origin f4c2f884b3fb006676aeef7e249055c5e2d8766d

以上使用的是 gitee 的源，如果 gitee 不能訪問，請替換為 github 的源

git remote remove origin
git remote add origin https://github.com/lindexi/lindexi_gd.git

獲取代碼之后，進入 RawluharkewalQeaninanel 文件夾

本作品采用知識共享署名-非商業性使用-相同方式共享 4.0 國際許可協議進行許可。歡迎轉載、使用、重新發布，但務必保留文章署名林德熙(包含鏈接:http://blog.csdn.net/lindexi_gd )，不得用於商業目的，基於本文修改后的作品務必以相同的許可發布。如有任何疑問，請與我聯系。