WPF 使用封装的 SharpDx 控件

上一篇告诉大家如何在 WPF 使用 SharpDx ，看起来代码比较复杂，所以本文告诉大家如何使用我封装的控件。

本文是一个系列，希望大家从第一篇开始看

在WPF 使用 SharpDX 在 D3DImage 显示我告诉大家如何在 WPF 使用，但是代码都是写在一个 MainPage ，所以下面我把代码封装一下，放在一个类。

我的代码可以复制一下放在自己的工程使用，现在我还不想做 Nuget 因为这个类还有性能问题。

使用这个类作为 Image 的 Source 会占用 3% 的 CPU ，而且这个类没有注释，关于这个类是如何写的请看WPF 使用 SharpDX 在 D3DImage 显示。

我会把这个类的代码放在文章最后，方便大家复制。

下面来告诉大家如何使用这个类。

首先复制代码，放在一个文件

写一个类继承 SharpDxImage ，这里我随意写一个类叫 SsgnnnaTkmlo ，这个类可以重写 OnRender ，也就是在绘制需要显示什么。

    public class SsgnnnaTkmlo : SharpDxImage
    {
        /// <inheritdoc />
        protected override void OnRender(RenderTarget renderTarget)
        {
        	//随便画一个矩形。下面的代码就是清空屏幕，参数 null 为透明，可以给其他的颜色。如何绘制请看文章。
            renderTarget.Clear(null);
            var brush = new SharpDX.Direct2D1.SolidColorBrush(renderTarget, new RawColor4(1, 0, 0, 1));
            var kvudjuzjsHlqiv = ran.Next((int) 100 - 10);
            var dfulTokpj = ran.Next((int) 100 - 10);
            renderTarget.DrawRectangle(
                new RawRectangleF(kvudjuzjsHlqiv, dfulTokpj, kvudjuzjsHlqiv + 10, dfulTokpj + 10), brush, 1);
        }
        private Random ran = new Random();
    }

需要告诉大家的是，传入 RenderTarget 的绘制和之前其他代码的绘制是一样，关于 SharpDx 的绘制我会在另一篇博客告诉大家。

然后打开 xaml 写入下面代码

            <Image x:Name="DcwtTmmwvcr">
                <Image.Source>
                    <local:SsgnnnaTkmlo x:Name="DrmKroh"></local:SsgnnnaTkmlo>
                </Image.Source>
            </Image>

当然，因为只是简单的例子，大家也可以写在后台代码。

在 xaml.cs　写下面代码，在　Load 绑定

            DcwtTmmwvcr.Loaded += (s, e) =>
            {
                DrmKroh.CreateAndBindTargets((int) ActualWidth, (int) ActualHeight);
            };

注意需要使用图片控件的 Load 事件，不然拿到的图片会模糊。

现在可以尝试运行一下，就可以看到一个随机出现的矩形。

下面就是封装类的代码。

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;
using SharpDX.Direct3D;

namespace WPFSharpDx
{
    public abstract class SharpDxImage : D3DImage
    {
        public void CreateAndBindTargets(int actualWidth, int actualHeight)
        {
            var width = Math.Max(actualWidth, 100);
            var height = Math.Max(actualHeight, 100);

            var renderDesc = new SharpDX.Direct3D11.Texture2DDescription
            {
                BindFlags = SharpDX.Direct3D11.BindFlags.RenderTarget | SharpDX.Direct3D11.BindFlags.ShaderResource,
                Format = SharpDX.DXGI.Format.B8G8R8A8_UNorm,
                Width = width,
                Height = height,
                MipLevels = 1,
                SampleDescription = new SharpDX.DXGI.SampleDescription(1, 0),
                Usage = SharpDX.Direct3D11.ResourceUsage.Default,
                OptionFlags = SharpDX.Direct3D11.ResourceOptionFlags.Shared,
                CpuAccessFlags = SharpDX.Direct3D11.CpuAccessFlags.None,
                ArraySize = 1
            };

            var device = new SharpDX.Direct3D11.Device(DriverType.Hardware,
                SharpDX.Direct3D11.DeviceCreationFlags.BgraSupport);

            var renderTarget = new SharpDX.Direct3D11.Texture2D(device, renderDesc);

            var surface = renderTarget.QueryInterface<SharpDX.DXGI.Surface>();

            var d2DFactory = new SharpDX.Direct2D1.Factory();

            var renderTargetProperties =
                new SharpDX.Direct2D1.RenderTargetProperties(
                    new SharpDX.Direct2D1.PixelFormat(SharpDX.DXGI.Format.Unknown,
                        SharpDX.Direct2D1.AlphaMode.Premultiplied));

            _d2DRenderTarget = new SharpDX.Direct2D1.RenderTarget(d2DFactory, surface, renderTargetProperties);

            SetRenderTarget(renderTarget);

            device.ImmediateContext.Rasterizer.SetViewport(0, 0, width, height);

            CompositionTarget.Rendering += CompositionTarget_Rendering;
        }


        protected abstract void OnRender(SharpDX.Direct2D1.RenderTarget renderTarget);

        private SharpDX.Direct3D9.Texture _renderTarget;
        private SharpDX.Direct2D1.RenderTarget _d2DRenderTarget;


        private void CompositionTarget_Rendering(object sender, EventArgs e)
        {
            Rendering();
        }


        private void Rendering()
        {
            _d2DRenderTarget.BeginDraw();

            OnRender(_d2DRenderTarget);

            _d2DRenderTarget.EndDraw();


            Lock();

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

            Unlock();
        }

        private void SetRenderTarget(SharpDX.Direct3D11.Texture2D target)
        {
            var format = TranslateFormat(target);
            var handle = GetSharedHandle(target);

            var presentParams = GetPresentParameters();
            var createFlags = SharpDX.Direct3D9.CreateFlags.HardwareVertexProcessing |
                              SharpDX.Direct3D9.CreateFlags.Multithreaded |
                              SharpDX.Direct3D9.CreateFlags.FpuPreserve;

            var d3DContext = new SharpDX.Direct3D9.Direct3DEx();
            var d3DDevice = new SharpDX.Direct3D9.DeviceEx(d3DContext, 0, SharpDX.Direct3D9.DeviceType.Hardware,
                IntPtr.Zero, createFlags,
                presentParams);

            _renderTarget = new SharpDX.Direct3D9.Texture(d3DDevice, target.Description.Width,
                target.Description.Height, 1,
                SharpDX.Direct3D9.Usage.RenderTarget, format, SharpDX.Direct3D9.Pool.Default, ref handle);

            using (var surface = _renderTarget.GetSurfaceLevel(0))
            {
                Lock();
                SetBackBuffer(D3DResourceType.IDirect3DSurface9, surface.NativePointer);
                Unlock();
            }
        }

        private static SharpDX.Direct3D9.PresentParameters GetPresentParameters()
        {
            var presentParams = new SharpDX.Direct3D9.PresentParameters();

            presentParams.Windowed = true;
            presentParams.SwapEffect = SharpDX.Direct3D9.SwapEffect.Discard;
            presentParams.DeviceWindowHandle = NativeMethods.GetDesktopWindow();
            presentParams.PresentationInterval = SharpDX.Direct3D9.PresentInterval.Default;

            return presentParams;
        }

        private IntPtr GetSharedHandle(SharpDX.Direct3D11.Texture2D texture)
        {
            using (var resource = texture.QueryInterface<SharpDX.DXGI.Resource>())
            {
                return resource.SharedHandle;
            }
        }

        private static SharpDX.Direct3D9.Format TranslateFormat(SharpDX.Direct3D11.Texture2D texture)
        {
            switch (texture.Description.Format)
            {
                case SharpDX.DXGI.Format.R10G10B10A2_UNorm:
                    return SharpDX.Direct3D9.Format.A2B10G10R10;
                case SharpDX.DXGI.Format.R16G16B16A16_Float:
                    return SharpDX.Direct3D9.Format.A16B16G16R16F;
                case SharpDX.DXGI.Format.B8G8R8A8_UNorm:
                    return SharpDX.Direct3D9.Format.A8R8G8B8;
                default:
                    return SharpDX.Direct3D9.Format.Unknown;
            }
        }

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