为什么 WTSVirtualChannelOpenEx return 31 "A device attached to the system is not functioning."

Question

我已经实现了远程桌面动态虚拟通道服务器和客户端，当我调用 WTSVirtualChannelOpenEx 时，它 returns false 和 GetLastError returns:

31
A device attached to the system is not functioning.

我在 OnNewChannelConnection 中设置 pAccept 和 pCallback 并返回 S_OK。我没有看到任何例外。使用 ECHO DVC 的测试在同一个客户端上打开得很好。

internal class DemoWtsListenerCallback : IWTSListenerCallback
{
    public void OnNewChannelConnection(IWTSVirtualChannel pChannel, 
        [MarshalAs(UnmanagedType.BStr)] string data, 
        out bool pAccept, out IWTSVirtualChannelCallback pCallback)
    {
        pAccept = true;
        pCallback = new DemoWtsChannelCallback(pChannel);
    }
}

为什么我的服务器出错？

Answer 1

mstsc 期望 pAccept 设置为 1 表示 true - 0xffffffff 的默认编组（根据 BOOL 类型应该没问题）不被解释是真的。

使用 [MarshalAs(UnmanagedType.Bool)] 到 return 1 为真。

internal class DemoWtsListenerCallback : IWTSListenerCallback
{
    public void OnNewChannelConnection(
        IWTSVirtualChannel pChannel, 
        [MarshalAs(UnmanagedType.BStr)] string data, 
        [MarshalAs(UnmanagedType.Bool)] out bool pAccept, 
        out IWTSVirtualChannelCallback pCallback)
    {
        pAccept = true;
        pCallback = new DemoWtsChannelCallback(pChannel);
    }
}

为什么 WTSVirtualChannelOpenEx return 31 "A device attached to the system is not functioning."

Why does WTSVirtualChannelOpenEx return 31 "A device attached to the system is not functioning."

c#

com

remote-desktop