Hello
I am attempting to get information(location info, location path, etc.) about a device that is currently connected to the computer in C++ Win32. I know how to get this information by using the function SetupDiGetDeviceRegistryProperty()
Before I use the function SetupDiGetDeviceRegistryProperty(), I must first call SetupDiGetSelectedDevice() because I need to pass a SP_DEVINFO_DATA as a parameter inside SetupDiGetDeviceRegistryProperty(). Is this correct?
My Problem: I can never get the device using the function SetupDiGetSelectedDevice(). When I call that function it always fails, ie, returns FALSE. GetLastError() returns the code e0000211 which I am not sure what that means.
Whats going wrong with my following code? If I am using the wrong function to *get* a device then what function do I use to get a device? I hope I dont have to enumerate over EVERY device present to find a device with the same GUID that I am looking for, thats a bit inefficient, I am thinking that windows may have a way to get a device by its GUID..?
INT_PTR WINAPI WinProcCallback( HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam )
{
switch (message)
{
case WM_DEVICECHANGE:
{
TCHAR strBuff[256];
PDEV_BROADCAST_HDR h = (PDEV_BROADCAST_HDR) lParam;
if (h->dbch_devicetype != DBT_DEVTYP_DEVICEINTERFACE) {
printf("h->dbch_devicetype != DBT_DEVTYP_DEVICEINTERFACE\n");
break;
}
PDEV_BROADCAST_DEVICEINTERFACE b = (PDEV_BROADCAST_DEVICEINTERFACE) h;
switch (wParam)
{
case DBT_DEVICEARRIVAL:
{
DWORD dataT = 0;
SP_DEVINFO_DATA deviceInfoData = {0};
deviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);
deviceInfoData.ClassGuid = b->dbcc_classguid;
// The following function always works and is successful
HDEVINFO hDevInfo = SetupDiGetClassDevs(&b->dbcc_classguid, NULL, NULL, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
if (hDevInfo == INVALID_HANDLE_VALUE) {
printf("hDevInfo == INVALID_HANDLE_VALUE\n");
break;
}
// ERROR OCCURS HERE: The following function ALWAYS returns false: whats going wrong?
if (SetupDiGetSelectedDevice(hDevInfo, &deviceInfoData) == FALSE) {
printf("SetupDiGetSelectedDevice(hDevInfo, &deviceInfoData) == FALSE\n");
break;
}
// Get device location information
DWORD buffersize = 0;
LPTSTR buffer = NULL;
while (!SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_LOCATION_INFORMATION, &dataT,
(PBYTE)buffer, buffersize, &buffersize))
{
if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
// Change the buffer size.
if (buffer)
LocalFree(buffer);
buffer = (LPTSTR)LocalAlloc(LPTR, buffersize);
}
}
printf("Data: %d: %s\n", i, buffer);
}
break;