Windows Sandbox中Desktop Duplication API返回空白图像问题

基于dotnet-window-capture项目实现Windows Sandbox屏幕录制，原代码如下：

var hr = _duplication.TryAcquireNextFrame(100, out _, out var desktopResourceOut);
if (hr.Failure)
    return null;

using var desktopTexture = desktopResourceOut.QueryInterface<Texture2D>();
var texture2dDescription = new Texture2DDescription {
    ArraySize = 1,
    BindFlags = BindFlags.ShaderResource | BindFlags.RenderTarget,
    CpuAccessFlags = CpuAccessFlags.None,
    Format = Format.B8G8R8A8_UNorm,
    Height = desktopTexture.Description.Height,
    MipLevels = 1,
    SampleDescription = new SampleDescription(1, 0),
    Usage = ResourceUsage.Default,
    Width = desktopTexture.Description.Width
};
var texture2d = new Texture2D(device, texture2dDescription);
device.ImmediateContext.CopyResource(desktopTexture, texture2d);

// release resources
desktopResourceOut.Dispose();
_duplication.ReleaseFrame();

return texture2d;

该代码在本地机器及RDP环境下可正常运行，但在Windows Sandbox中始终返回空白窗口。

排查与修改过程 #

原代码存在两处不足：

• 未处理TryAcquireNextFrame的所有失败情况
• 忽略OutputDuplicateFrameInformation，未检查LastPresentTime（虽与MSDN文档描述矛盾，但有相关讨论指出需检查）

完善错误处理及OutputDuplicateFrameInformation检查后，Windows Sandbox中出现以下现象：

• 移动鼠标时TryAcquireNextFrame大多成功，但OutputDuplicateFrameInformation.LastPresentTime始终为0
• 仅出现错误码0x887A0027（超时，提示无画面更新需等待）
• 忽略LastPresentTime==0时，texture2d为黑色
• 尝试复制desktopTexture的Texture2DDescription参数以避免CopyResource静默失败，无效果
• 枚举适配器及输出后确认系统仅存在一个Output

最终修改后的代码仍返回空白texture2d：

var hr = _duplication.TryAcquireNextFrame(100, out var frameInfo, out var desktopResourceOut);
if (hr.Failure) {
    if (hr.Code == unchecked((int)0x887A0027)) return null; // no changes
    hr.CheckError();
    return null;
}

try {
    //if (frameInfo.LastPresentTime == 0) {
    //    return null; // in Sandbox all frames go here
    //}

    using var desktopTexture = desktopResourceOut.QueryInterface<Texture2D>();
    var texture2dDescription = new Texture2DDescription {
        ArraySize = desktopTexture.Description.ArraySize,
        BindFlags = BindFlags.ShaderResource | BindFlags.RenderTarget,
        CpuAccessFlags = CpuAccessFlags.None,
        Format = desktopTexture.Description.Format,
        Height = desktopTexture.Description.Height,
        MipLevels = 1,
        SampleDescription = new SampleDescription(1, 0),
        Usage = ResourceUsage.Default,
        Width = desktopTexture.Description.Width
    };
    var texture2d = new Texture2D(device, texture2dDescription);
    device.ImmediateContext.CopyResource(desktopTexture, texture2d);

    return texture2d;
} finally {
    // release resources
    desktopResourceOut.Dispose();
    _duplication.ReleaseFrame();
}

替代方案尝试 #

尝试使用WinRT的IGraphicsCaptureItemInterop::CreateForMonitor(hmon, new Guid("79C3F95B-31F7-4EC2-A464-632EF5D30760"))作为替代方案，但失败并返回错误码0x80040154（REGDB_E_CLASSNOTREG）。

内容的提问来源于stack exchange，提问作者LOST