在
EnumDisplayDevices API中提供了一种解决GDI到SetupAPI的方法。如果您将
EDD_GET_DEVICE_INTERFACE_NAME传递给dwFlags，监视器枚举将返回以下形式的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}
设备ID字段现在与以下C#片段中检索的结果匹配：
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);
}
示例输出：
InstanceID: DISPLAY\DELA06E\5&2E2FEFEA&0&UID1078018
DevicePath: \\?\display#dela06e#5&2e2fefea&0&uid1078018#{e6f07b5f-ee97-4a90-b076-33f57bf4eaa7}
原始的EnumDisplayDevices中的DeviceName与Forms.Screen.DeviceName属性匹配。
有了这两个信息，现在可以使用以下片段在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;
}
最终，此代码中的
DisplayDetails.GetMonitorDetails()方法可以用于解析VESA描述符块。
