寻找Forms.Screen.DeviceName到Monitor EDID信息的可靠映射

Question

我正在开发一个应用程序,它将在相应监视器上的对话框上显示从EDID块(监视器型号,ID,S/N等)派生的信息.

此代码适用于查找显示的EDID信息.它通过枚举HKLM\SYSTEM\CurrentControlSet\Enum\DISPLAY\[Monitor]\[PnPID]\Device Parameters\EDID下的DISPLAY键来提取EDID信息.

更新:上面的代码依赖于PnP使用注册表的"副作用".我现在使用SetupAPI枚举监视器,它正确处理连接/删除的监视器(与上面链接中的代码不同).

我试图将Windows.Forms.Screen.AllScreens [](\\.\ DISPLAY1,\\.\ DISPLAY2等)中的每个屏幕与上述注册表检查返回的条目相关联.

注意:在下面的代码块中,DisplayDetails.GetMonitorDetails()现已使用SetupAPI替换为更强大的注册表枚举代码,但返回的数据是相同的.

例如

private void Form1_Load(object sender, EventArgs e)
{
    Console.WriteLine("Polling displays on {0}:", System.Environment.MachineName);
    int i = 0;
    foreach ( DisplayDetails dd in DisplayDetails.GetMonitorDetails())
    {
        Console.WriteLine( "Info: Model: {0}, MonitorID: {1}, PnPID: {2}, Serial#:{3}", dd.Model, dd.MonitorID, dd.PnPID, dd.SerialNumber );
        Console.WriteLine( "Does this correlate to Screen: {0}?", Screen.AllScreens[i++].DeviceName );
    }
}

输出:

信息:型号:DELL P2411H,MonitorID:DELA06E,PnPID:5&2e2fefea&0&UID1078018,Serial#:F8NDP0C ... PU

这是否与Screen相关:\\.\ DISPLAY1？

信息:型号:DELL P2411H,MonitorID:DELA06E,PnPID:5&2e2fefea&0&UID1078019,Serial#:F8NDP0C ... AU

这与Screen相关:\\.\ DISPLAY2？

---

答:没有

在测试中,我发现它们没有可靠的关联(我有一个系统,其中枚举的第一个显示是\\.\ DISPLAY2).

我的问题: 有没有办法可靠地获取给定Forms.Screen的EDID信息？ 我可以获得EDID块,但是没有找到将此关联到UI顶级表单的路径.提示用户是不可取的,因为在我的用例中,两个(或更多)监视器可能是相同的型号和分辨率,并且仅在S/N中相差几位.

我已经在Forms.Screen API,Win32 EnumDisplay,其他注册表GUID(PnP和驱动程序相关)之后寻找路径,但是没有找到任何有希望的路径.

我还调查了WMI Win32_DesktopMonitor API(Windows 7),但它似乎没有任何更多信息可以帮助我将它与Windows.Forms.Screen.AllScreens []条目相关联.

我怀疑是否有办法做到这一点,它是通过SetupAPI,但我还没有找到它.

Answer 1

EnumDisplayDevices API中提供了一种将GDI解析为SetupAPI的方法.如果您为dwFlags 传入EDD_GET_DEVICE_INTERFACE_NAME,则监视器枚举将返回以下格式的DeviceID信息:

Monitor 0 info:
DeviceName: \\.\DISPLAY1
MonitorInfo: Dell P2411H(Digital)
DeviceID: \\?\DISPLAY#DELA06E#5&2e2fefea&0&UID1078018#{e6f07b5f-ee97-4a90-b076-3
3f57bf4eaa7}
Monitor 1 info:
DeviceName: \\.\DISPLAY2
MonitorInfo: Dell P2411H(Digital)
DeviceID: \\?\DISPLAY#DELA06E#5&2e2fefea&0&UID1078019#{e6f07b5f-ee97-4a90-b076-3
3f57bf4eaa7}

DeviceID字段现在匹配didd.DevicePath的结果,如下面的C#片段中所检索:

    Guid MonitorGUID = new Guid(Win32.GUID_DEVINTERFACE_MONITOR);

    // We start at the "root" of the device tree and look for all
    // devices that match the interface GUID of a monitor
    IntPtr h = Win32.SetupDiGetClassDevs(ref MonitorGUID, IntPtr.Zero, IntPtr.Zero, (uint)(Win32.DIGCF_PRESENT | Win32.DIGCF_DEVICEINTERFACE));
    if (h.ToInt64() != Win32.INVALID_HANDLE_VALUE)
    {
        bool Success = true;
        uint i = 0;
        while (Success)
        {
            // create a Device Interface Data structure
            Win32.SP_DEVICE_INTERFACE_DATA dia = new Win32.SP_DEVICE_INTERFACE_DATA();
            dia.cbSize = (uint)Marshal.SizeOf(dia);

            // start the enumeration 
            Success = Win32.SetupDiEnumDeviceInterfaces(h, IntPtr.Zero, ref MonitorGUID, i, ref dia);
            if (Success)
            {
                // build a DevInfo Data structure
                Win32.SP_DEVINFO_DATA da = new Win32.SP_DEVINFO_DATA();
                da.cbSize = (uint)Marshal.SizeOf(da);

                // build a Device Interface Detail Data structure
                Win32.SP_DEVICE_INTERFACE_DETAIL_DATA didd = new Win32.SP_DEVICE_INTERFACE_DETAIL_DATA();
                didd.cbSize = (uint)(4 + Marshal.SystemDefaultCharSize); // trust me :)

                // now we can get some more detailed information
                uint nRequiredSize = 0;
                uint nBytes = Win32.BUFFER_SIZE;
                if (Win32.SetupDiGetDeviceInterfaceDetail(h, ref dia, ref didd, nBytes, out nRequiredSize, ref da))
                {
                    // Now we get the InstanceID
                    IntPtr ptrInstanceBuf = Marshal.AllocHGlobal((int)nBytes);
                    Win32.CM_Get_Device_ID(da.DevInst, ptrInstanceBuf, (int)nBytes, 0);
                    string InstanceID = Marshal.PtrToStringAuto(ptrInstanceBuf);
                    Console.WriteLine("InstanceID: {0}", InstanceID );
                    Marshal.FreeHGlobal(ptrInstanceBuf);

                    Console.WriteLine("DevicePath: {0}", didd.DevicePath );
                }
                i++;
            }
        }
    }
    Win32.SetupDiDestroyDeviceInfoList(h);
}

样本输出:

InstanceID: DISPLAY\DELA06E\5&2E2FEFEA&0&UID1078018
DevicePath: \\?\display#dela06e#5&2e2fefea&0&uid1078018#{e6f07b5f-ee97-4a90-b076-33f57bf4eaa7}

原始EnumDisplayDevices中的DeviceName与Forms.Screen.DeviceName属性匹配.

有了这两条信息,现在可以使用如下所示的片段在SetupDIEnumDeviceInterface遍历期间读取EDID块:

private static byte[] GetMonitorEDID(IntPtr pDevInfoSet, SP_DEVINFO_DATA deviceInfoData)
{
    IntPtr hDeviceRegistryKey = SetupDiOpenDevRegKey(pDevInfoSet, ref deviceInfoData,
        DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_QUERY_VALUE);
    if (hDeviceRegistryKey == IntPtr.Zero)
    {
        throw new Exception("Failed to open a registry key for device-specific configuration information");
    }

    IntPtr ptrBuff = Marshal.AllocHGlobal((int)256);
    try
    {
        RegistryValueKind lpRegKeyType = RegistryValueKind.Binary;
        int length = 256;
        uint result = RegQueryValueEx(hDeviceRegistryKey, "EDID", 0, ref lpRegKeyType, ptrBuff, ref length);
        if (result != 0)
        {
            throw new Exception("Can not read registry value EDID for device " + deviceInfoData.ClassGuid);
        }
    }
    finally
    {
        RegCloseKey(hDeviceRegistryKey);
    }
    byte[] edidBlock = new byte[256];
    Marshal.Copy(ptrBuff, edidBlock, 0, 256);
    Marshal.FreeHGlobal(ptrBuff);
    return edidBlock;
}

最后,可以为VESA描述符块解析,如本代码中的DisplayDetails.GetMonitorDetails()方法所示.