我正在尝试获取有关当前在C ++ Win32中连接到计算机的设备的信息(位置信息,位置路径等)。我知道如何使用函数SetupDiGetDeviceRegistryProperty()
获取此信息在我使用函数SetupDiGetDeviceRegistryProperty()
之前,我必须先调用SetupDiGetSelectedDevice(),因为我需要在SP_DEVINFO_DATA
内传递SetupDiGetDeviceRegistryProperty()
作为参数。这是对的吗?
我的问题:我永远无法使用SetupDiGetSelectedDevice()
功能获取设备。当我调用该函数时,它总是失败,即返回FALSE。 GetLastError()
返回代码e0000211,我不确定这意味着什么。
我的以下代码出了什么问题?如果我使用错误的功能获取设备,那么我将使用什么功能来获取设备?
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;
}
switch (wParam)
{
case DBT_DEVICEARRIVAL:
{
DWORD dataT = 0;
SP_DEVINFO_DATA deviceInfoData = {0};
deviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);
deviceInfoData.ClassGuid = h->dbcc_classguid;
// The following function always works and is successful
HDEVINFO hDevInfo = SetupDiGetClassDevs(&h->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;