protected override void WndProc(ref Message m)
{
try
{
if (m.Msg == 0x0219)
{
switch (m.WParam.ToInt32())
{
case 0x8000:
if (HIDDevice.TheHIDDevice == null)
{
HIDDevice.TheHIDDevice = HIDDevice.FindDevice();
}
HIDUI();
break;
case 0x8004:
try
{
HIDDevice.TheHIDDevice.Dispose();
HIDDevice.TheHIDDevice = null;
}
catch { }
HIDUI();
break;
default:
break;
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
base.WndProc(ref m);
}
void ReHIDUI()
{
if (HIDDevice.TheHIDDevice == null)
{
HIDDevice.TheHIDDevice = HIDDevice.FindDevice();
}
HIDUI();
}
public static HIDDevice FindDevice()
{
string strPath = string.Empty;
string strSearch = string.Format("vid_{0:x4}&pid_{1:x4}", VendorID, ProductID); // first, build the path search string
Guid gHid;
HidD_GetHidGuid(out gHid); // next, get the GUID from Windows that it uses to represent the HID USB interface
IntPtr hInfoSet = SetupDiGetClassDevs(ref gHid, null, IntPtr.Zero, DIGCF_DEVICEINTERFACE | DIGCF_PRESENT); // this gets a list of all HID devices currently connected to the computer (InfoSet)
try
{
DeviceInterfaceData oInterface = new DeviceInterfaceData(); // build up a device interface data block
oInterface.Size = Marshal.SizeOf(oInterface);
// Now iterate through the InfoSet memory block assigned within Windows in the call to SetupDiGetClassDevs
// to get device details for each device connected
int nIndex = 0;
while (SetupDiEnumDeviceInterfaces(hInfoSet, 0, ref gHid, (uint)nIndex, ref oInterface)) // this gets the device interface information for a device at index 'nIndex' in the memory block
{
string strDevicePath = GetDevicePath(hInfoSet, ref oInterface); // get the device path (see helper method 'GetDevicePath')
if (strDevicePath.IndexOf(strSearch) >= 0) // do a string search, if we find the VID/PID string then we found our device!
{
HIDDevice oNewDevice = null;
try
{
int retry = 3;
while (retry != 0)
{
//Thread.Sleep(3000);
oNewDevice = new HIDDevice(); // create an instance of the class for this device
oNewDevice.Initialise(strDevicePath); // initialise it with the device path
if (oNewDevice.CheckDevice())
{
return(oNewDevice); // and return it
}
else
{
oNewDevice.Dispose();
oNewDevice = null;
}
retry--;
}
}
catch
{
if (oNewDevice != null)
{
oNewDevice.Dispose();
oNewDevice = null;
}
}
}
nIndex++; // if we get here, we didn't find our device. So move on to the next one.
}
}
finally
{
// Before we go, we have to free up the InfoSet memory reserved by SetupDiGetClassDevs
SetupDiDestroyDeviceInfoList(hInfoSet);
}
return(null); // oops, didn't find our device
}
