问题
I've registered a window with RegisterDeviceNotification and can successfully recieve DEV_BROADCAST_DEVICEINTERFACE messages. However, the dbcc_name
field in the returned struct is always empty. The struct I have is defined as such:
[StructLayout(LayoutKind.Sequential)]
public struct DEV_BROADCAST_DEVICEINTERFACE
{
public int dbcc_size;
public int dbcc_devicetype;
public int dbcc_reserved;
public Guid dbcc_classguid;
[MarshalAs(UnmanagedType.LPStr)]
public string dbcc_name;
}
And I'm using Marshal.PtrToStructure
on the LParam of the WM_DEVICECHANGE message.
Should this be working?
Or even better... Is there an alternative way to get the name of a device upon connection?
EDIT (02/05/2010 20:56GMT):
I found out how to get the dbcc_name field to populate by doing this:
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct DEV_BROADCAST_DEVICEINTERFACE
{
public int dbcc_size;
public int dbcc_devicetype;
public int dbcc_reserved;
public Guid dbcc_classguid;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=255)]
public string dbcc_name;
}
but I still need a way to get a "Friendly" name from what is int dbcc_name. It looks like the following:
\?\USB#VID_05AC&PID_1294&MI_00#0#{6bdd1fc6-810f-11d0-bec7-08002be2092f}
And I really just want it to say "Apple iPhone" (which is what the device is in this case).
回答1:
Well, as noted above I found out how to get dbcc_name to populate correctly. I found that this was the easiest way to get the device name:
private static string GetDeviceName(DEV_BROADCAST_DEVICEINTERFACE dvi)
{
string[] Parts = dvi.dbcc_name.Split('#');
if (Parts.Length >= 3)
{
string DevType = Parts[0].Substring(Parts[0].IndexOf(@"?\") + 2);
string DeviceInstanceId = Parts[1];
string DeviceUniqueID = Parts[2];
string RegPath = @"SYSTEM\CurrentControlSet\Enum\" + DevType + "\\" + DeviceInstanceId + "\\" + DeviceUniqueID;
RegistryKey key = Registry.LocalMachine.OpenSubKey(RegPath);
if (key != null)
{
object result = key.GetValue("FriendlyName");
if (result != null)
return result.ToString();
result = key.GetValue("DeviceDesc");
if (result != null)
return result.ToString();
}
}
return String.Empty;
}
回答2:
This information can also be acquired more formally through SetupAPI. Pass dbcc_name
to SetupDiOpenDeviceInterface
and get the friendly name with SetupDiGetDeviceRegistryProperty
passing in SPDRP_FRIENDLYNAME
.
Here's some Delphi code that will do it. (Sorry, you'll have to translate to C# independently).
function ConvertDbccNameToFriendlyName(aDeviceInterfaceDbccName : string) : string;
var
deviceInfoHandle : HDEVINFO;
deviceInfoData : SP_DEVINFO_DATA;
deviceInterfaceData : SP_DEVICE_INTERFACE_DATA;
deviceInstanceId : string;
memberIndex : Cardinal;
begin
result := '';
// Create a new empty "device info set"
deviceInfoHandle := SetupDiCreateDeviceInfoList(nil, 0);
if deviceInfoHandle <> INVALID_HANDLE_VALUE then
begin
try
// Add "aDeviceInterfaceDbccName" to the device info set
FillChar(deviceInterfaceData, SizeOf(deviceInterfaceData), 0);
deviceInterfaceData.cbSize := SizeOf(deviceInterfaceData);
if SetupDiOpenDeviceInterface(deviceInfoHandle, PChar(aDeviceInterfaceDbccName), 0, @deviceInterfaceData) then
begin
try
// iterate over the device info set
// (though I only expect it to contain one item)
memberIndex := 0;
while true do
begin
// get device info that corresponds to the next memberIndex
FillChar(deviceInfoData, SizeOf(deviceInfoData), 0);
deviceInfoData.cbSize := SizeOf(deviceInfoData);
if not SetupDiEnumDeviceInfo(deviceInfoHandle, memberIndex, deviceInfoData) then
begin
// The enumerator is exhausted when SetupDiEnumDeviceInfo returns false
break;
end
else
begin
Inc(memberIndex);
end;
// Get the friendly name for that device info
if TryGetDeviceFriendlyName(deviceInfoHandle, deviceInfoData, {out} friendlyName) then
begin
result := friendlyName;
break;
end;
end;
finally
SetupDiDeleteDeviceInterfaceData(deviceInfoHandle, deviceInterfaceData);
end;
end;
finally
SetupDiDestroyDeviceInfoList(deviceInfoHandle);
end;
end;
end;
function TryGetDeviceFriendlyName(
var aDeviceInfoHandle : HDEVINFO;
var aDeviceInfoData : SP_DEVINFO_DATA;
out aFriendlyName : string) : boolean;
var
valueBuffer : array of byte;
regProperty : Cardinal;
propertyRegDataType : DWord;
friendlyNameByteSize : Cardinal;
success : boolean;
begin
aFriendlyName := '';
result := false;
// Get the size of the friendly device name
regProperty := SPDRP_FRIENDLYNAME;
friendlyNameByteSize := 0;
SetupDiGetDeviceRegistryProperty(
aDeviceInfoHandle, // handle to device information set
aDeviceInfoData, // pointer to SP_DEVINFO_DATA structure
regProperty, // property to be retrieved
propertyRegDataType, // pointer to variable that receives the data type of the property
nil, // pointer to PropertyBuffer that receives the property
0, // size, in bytes, of the PropertyBuffer buffer.
friendlyNameByteSize); // pointer to variable that receives the required size of PropertyBuffer
// Prepare a buffer for the friendly device name (plus space for a null terminator)
SetLength(valueBuffer, friendlyNameByteSize + sizeof(char));
success := SetupDiGetDeviceRegistryProperty(
aDeviceInfoHandle,
aDeviceInfoData,
regProperty,
propertyRegDataType,
@valueBuffer[0],
friendlyNameByteSize,
friendlyNameByteSize);
if success then
begin
// Ensure that only 'friendlyNameByteSize' bytes are used.
// Ensure that the string is null-terminated.
PChar(@valueBuffer[friendlyNameByteSize])^ := char(0);
// Get the returned value as a string
aFriendlyName := StrPas(PChar(@valueBuffer[0]));
end;
result := success;
end;
Finally... if you need a way to uniquely identify a USB device (not what you asked for, but commonly this is also needed), look into SetupDiGetDeviceInstanceId
.
回答3:
It is likely you need to change this slightly
[StructLayout(LayoutKind.Sequential)] public struct DEV_BROADCAST_DEVICEINTERFACE { public int dbcc_size; public int dbcc_devicetype; public int dbcc_reserved; public Guid dbcc_classguid; [MarshalAs(UnmanagedType.LPStr)] public StringBuilder dbcc_name; }
Set the dbcc_size
to 255, and construct the StringBuilder as shown below:
DEV_BROADCAST_DEVICEINTERFACE dbd = new DEV_BROADCAST_DEVICEINTERFACE; dbd.dbcc_size = 255; dbd.dbcc_name = new StringBuilder(dbd.dbcc_size);
Then pass that structure in, the value of dbcc_name
should be populated.
Edit: after snicker's comment...I thought of this another way...
public struct DEV_BROADCAST_DEVICEINTERFACE { public int dbcc_size; public int dbcc_devicetype; public int dbcc_reserved; public Guid dbcc_classguid; [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst = 255, ArraySubType = System.Runtime.InteropServices.UnmanagedType.LPArray)] public string dbcc_name; }
Set the dbcc_size
to 255, and take it from there...
Edit#2: This is interesting...am not so sure now, I found this article that uses RegisterDeviceNotification
on Codeproject and it uses a different way of RegisterDeviceNotification in that the struct is marshalled into a IntPtr
and is used to call the API...
来源:https://stackoverflow.com/questions/2208722/how-to-get-friendly-device-name-from-dev-broadcast-deviceinterface-and-device-in