sl@0: using System;
sl@0: using System.Diagnostics;
sl@0: using System.Runtime.InteropServices; 
sl@0: using System.Windows.Forms;
sl@0: 
sl@0: namespace GenericHid
sl@0: {
sl@0: 	/// <summary>
sl@0: 	/// Routine for detecting devices using Win32 SetupDi functions.
sl@0: 	/// </summary>
sl@0: 	/// 
sl@0: 	sealed internal partial class DeviceManagement
sl@0: 	{
sl@0: 		private const String ModuleName = "Device Management";
sl@0: 
sl@0: 		///  <summary>
sl@0: 		///  Provides a central mechanism for exception handling.
sl@0: 		///  Displays a message box that describes the exception.
sl@0: 		///  </summary>
sl@0: 		///  
sl@0: 		///  <param name="name"> the module where the exception occurred. </param>
sl@0: 		///  <param name="e"> the exception </param>
sl@0: 
sl@0: 		internal static void DisplayException(String name, Exception e)
sl@0: 		{
sl@0: 			try
sl@0: 			{
sl@0: 				//  Create an error message.
sl@0: 
sl@0: 				String message = "Exception: " + e.Message + Environment.NewLine + "Module: " + name + Environment.NewLine + "Method: " +
sl@0: 						  e.TargetSite.Name;
sl@0: 
sl@0: 				const String caption = "Unexpected Exception";
sl@0: 
sl@0: 				MessageBox.Show(message, caption, MessageBoxButtons.OK);
sl@0: 				Debug.Write(message);
sl@0: 			}
sl@0: 			catch (Exception ex)
sl@0: 			{
sl@0: 				DisplayException(ModuleName, ex);
sl@0: 				throw;
sl@0: 			}
sl@0: 		}
sl@0: 
sl@0: 		///  <summary>
sl@0: 		///  Use SetupDi API functions to retrieve the device path name of an
sl@0: 		///  attached device that belongs to a device interface class.
sl@0: 		///  </summary>
sl@0: 		///  
sl@0: 		///  <param name="myGuid"> an interface class GUID. </param>
sl@0: 		///  <param name="devicePathName"> a pointer to the device path name 
sl@0: 		///  of an attached device. </param>
sl@0: 		///  
sl@0: 		///  <returns>
sl@0: 		///   True if a device is found, False if not. 
sl@0: 		///  </returns>
sl@0: 
sl@0: 		internal Boolean FindDeviceFromGuid(Guid myGuid, ref String[] devicePathName)
sl@0: 		{
sl@0: 			Int32 bufferSize = 0;
sl@0: 			var deviceInfoSet = new IntPtr();
sl@0: 			Boolean lastDevice = false;
sl@0: 			var myDeviceInterfaceData = new NativeMethods.SP_DEVICE_INTERFACE_DATA();
sl@0: 
sl@0: 			try
sl@0: 			{
sl@0: 				Int32 memberIndex;
sl@0: 
sl@0: 				// ***
sl@0: 				//  API function
sl@0: 
sl@0: 				//  summary 
sl@0: 				//  Retrieves a device information set for a specified group of devices.
sl@0: 				//  SetupDiEnumDeviceInterfaces uses the device information set.
sl@0: 
sl@0: 				//  parameters 
sl@0: 				//  Interface class GUID.
sl@0: 				//  Null to retrieve information for all device instances.
sl@0: 				//  Optional handle to a top-level window (unused here).
sl@0: 				//  Flags to limit the returned information to currently present devices 
sl@0: 				//  and devices that expose interfaces in the class specified by the GUID.
sl@0: 
sl@0: 				//  Returns
sl@0: 				//  Handle to a device information set for the devices.
sl@0: 				// ***
sl@0: 
sl@0: 				deviceInfoSet = NativeMethods.SetupDiGetClassDevs(ref myGuid, IntPtr.Zero, IntPtr.Zero, NativeMethods.DIGCF_PRESENT | NativeMethods.DIGCF_DEVICEINTERFACE);
sl@0: 
sl@0: 				bool deviceFound = false;
sl@0: 				memberIndex = 0;
sl@0: 
sl@0: 				// The cbSize element of the MyDeviceInterfaceData structure must be set to
sl@0: 				// the structure's size in bytes. 
sl@0: 				// The size is 28 bytes for 32-bit code and 32 bits for 64-bit code.
sl@0: 
sl@0: 				myDeviceInterfaceData.cbSize = Marshal.SizeOf(myDeviceInterfaceData);
sl@0: 
sl@0: 				do
sl@0: 				{
sl@0: 					// Begin with 0 and increment through the device information set until
sl@0: 					// no more devices are available.
sl@0: 				
sl@0: 					// ***
sl@0: 					//  API function
sl@0: 
sl@0: 					//  summary
sl@0: 					//  Retrieves a handle to a SP_DEVICE_INTERFACE_DATA structure for a device.
sl@0: 					//  On return, MyDeviceInterfaceData contains the handle to a
sl@0: 					//  SP_DEVICE_INTERFACE_DATA structure for a detected device.
sl@0: 
sl@0: 					//  parameters
sl@0: 					//  DeviceInfoSet returned by SetupDiGetClassDevs.
sl@0: 					//  Optional SP_DEVINFO_DATA structure that defines a device instance 
sl@0: 					//  that is a member of a device information set.
sl@0: 					//  Device interface GUID.
sl@0: 					//  Index to specify a device in a device information set.
sl@0: 					//  Pointer to a handle to a SP_DEVICE_INTERFACE_DATA structure for a device.
sl@0: 
sl@0: 					//  Returns
sl@0: 					//  True on success.
sl@0: 					// ***
sl@0: 
sl@0: 					Boolean success = NativeMethods.SetupDiEnumDeviceInterfaces
sl@0: 						(deviceInfoSet,
sl@0: 						 IntPtr.Zero,
sl@0: 						 ref myGuid,
sl@0: 						 memberIndex,
sl@0: 						 ref myDeviceInterfaceData);
sl@0: 
sl@0: 					// Find out if a device information set was retrieved.
sl@0: 
sl@0: 					if (!success)
sl@0: 					{
sl@0: 						lastDevice = true;
sl@0: 					}
sl@0: 					else
sl@0: 					{
sl@0: 						// A device is present.
sl@0: 
sl@0: 						// ***
sl@0: 						//  API function: 
sl@0: 
sl@0: 						//  summary:
sl@0: 						//  Retrieves an SP_DEVICE_INTERFACE_DETAIL_DATA structure
sl@0: 						//  containing information about a device.
sl@0: 						//  To retrieve the information, call this function twice.
sl@0: 						//  The first time returns the size of the structure.
sl@0: 						//  The second time returns a pointer to the data.
sl@0: 
sl@0: 						//  parameters
sl@0: 						//  DeviceInfoSet returned by SetupDiGetClassDevs
sl@0: 						//  SP_DEVICE_INTERFACE_DATA structure returned by SetupDiEnumDeviceInterfaces
sl@0: 						//  A returned pointer to an SP_DEVICE_INTERFACE_DETAIL_DATA 
sl@0: 						//  Structure to receive information about the specified interface.
sl@0: 						//  The size of the SP_DEVICE_INTERFACE_DETAIL_DATA structure.
sl@0: 						//  Pointer to a variable that will receive the returned required size of the 
sl@0: 						//  SP_DEVICE_INTERFACE_DETAIL_DATA structure.
sl@0: 						//  Returned pointer to an SP_DEVINFO_DATA structure to receive information about the device.
sl@0: 
sl@0: 						//  Returns
sl@0: 						//  True on success.
sl@0: 						// ***                     
sl@0: 
sl@0: 						NativeMethods.SetupDiGetDeviceInterfaceDetail
sl@0: 							(deviceInfoSet,
sl@0: 							 ref myDeviceInterfaceData,
sl@0: 							 IntPtr.Zero,
sl@0: 							 0,
sl@0: 							 ref bufferSize,
sl@0: 							 IntPtr.Zero);
sl@0: 
sl@0: 						// Allocate memory for the SP_DEVICE_INTERFACE_DETAIL_DATA structure using the returned buffer size.
sl@0: 
sl@0: 						IntPtr detailDataBuffer = Marshal.AllocHGlobal(bufferSize);
sl@0: 
sl@0: 						// Store cbSize in the first bytes of the array. Adjust for 32- and 64-bit systems.
sl@0: 
sl@0:                         Int32 cbsize;
sl@0: 
sl@0:                         if (IntPtr.Size == 4)
sl@0:                         {
sl@0:                             cbsize = 4 + Marshal.SystemDefaultCharSize;
sl@0:                         }
sl@0:                         else
sl@0:                         {
sl@0:                             cbsize = 8;
sl@0:                         }
sl@0: 
sl@0: 						Marshal.WriteInt32(detailDataBuffer, cbsize);                        
sl@0: 
sl@0: 						// Call SetupDiGetDeviceInterfaceDetail again.
sl@0: 						// This time, pass a pointer to DetailDataBuffer
sl@0: 						// and the returned required buffer size.
sl@0: 
sl@0: 						NativeMethods.SetupDiGetDeviceInterfaceDetail
sl@0: 							(deviceInfoSet,
sl@0: 							 ref myDeviceInterfaceData,
sl@0: 							 detailDataBuffer,
sl@0: 							 bufferSize,
sl@0: 							 ref bufferSize,
sl@0: 							 IntPtr.Zero);
sl@0: 
sl@0: 						// Get the address of the devicePathName.
sl@0: 
sl@0: 						var pDevicePathName = new IntPtr(detailDataBuffer.ToInt64() + 4);
sl@0: 
sl@0: 						// Get the String containing the devicePathName.
sl@0: 
sl@0: 						devicePathName[memberIndex] = Marshal.PtrToStringAuto(pDevicePathName);
sl@0: 
sl@0: 						if (detailDataBuffer != IntPtr.Zero)
sl@0: 						{
sl@0: 							// Free the memory allocated previously by AllocHGlobal.
sl@0: 
sl@0: 							Marshal.FreeHGlobal(detailDataBuffer);
sl@0: 						}
sl@0: 						deviceFound = true;
sl@0: 					}
sl@0: 					memberIndex = memberIndex + 1;
sl@0: 				}
sl@0: 				while (!lastDevice);
sl@0: 
sl@0: 				return deviceFound;
sl@0: 			}
sl@0: 			finally
sl@0: 			{
sl@0: 				// ***
sl@0: 				//  API function
sl@0: 
sl@0: 				//  summary
sl@0: 				//  Frees the memory reserved for the DeviceInfoSet returned by SetupDiGetClassDevs.
sl@0: 
sl@0: 				//  parameters
sl@0: 				//  DeviceInfoSet returned by SetupDiGetClassDevs.
sl@0: 
sl@0: 				//  returns
sl@0: 				//  True on success.
sl@0: 				// ***
sl@0: 
sl@0: 				if (deviceInfoSet != IntPtr.Zero)
sl@0: 				{
sl@0: 					NativeMethods.SetupDiDestroyDeviceInfoList(deviceInfoSet);
sl@0: 				}
sl@0: 			}
sl@0: 		}
sl@0: 	}
sl@0: }
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0: