Detect hardware in PC (windows) through C# code by Win32_PnPEntity and ManagementObjectSearcher

I was working with some hardware (Smart card reader), which needs to interact with my C# code. When I was starting, I was really a fresher in this area. My objective is to detect the device attached in my pc. If it is attached an event will fire, and same will happen on the remove. To do that, I created a windows service. But now the challenge is device detection on my pc.

To do that, I have to get the details from hardware manager of my pc. I got the solution from c# itself.

using System.Management;

It will help to get hardware information from pc using c# code. The code is as follows-

static bool getDeviceFromHWM(string deviceGuid)

        {

            ManagementObjectSearcher mos =

                   new ManagementObjectSearcher(@"\root\cimv2", @"Select * From Win32_PnPEntity WHERE ClassGuid = '"+deviceGuid+"'");

            ManagementObjectCollection moc = mos.Get();

            foreach (ManagementObject mo in moc)

            {

                PropertyDataCollection devsProperties = mo.Properties;

                foreach (PropertyData devProperty in devsProperties)

                {

                    if (devProperty.Type == CimType.DateTime)

                    {

                        if (devProperty.Value != null)

                        {

                                                    }

                    }

                    else

                    {

                        Console.WriteLine(" {0}----->{1}",devProperty.Name, devProperty.Value);

                    }

                }

            }

            if (moc.Count > 0)

                return true;

            else

                return false;

        }

Now, function receives one input “deviceGUID”. It is nothing but the device type id, common for windows. So , to find a smart card reader and smart card from my pc I have to use a GUID -{990a2bd7-e738-46c7-b26f-1cf8fb9f1391} and {50DD5230-BA8A-11D1-BF5D-0000F805F530}.

Basic Class GUID table

Class	GUID	Device Description
CDROM	4D36E965-E325-11CE-BFC1-08002BE10318	CD/DVD/Blu-ray drives
DiskDrive	4D36E967-E325-11CE-BFC1-08002BE10318	Hard drives
Display	4D36E968-E325-11CE-BFC1-08002BE10318	Video adapters
FDC	4D36E969-E325-11CE-BFC1-08002BE10318	Floppy controllers
FloppyDisk	4D36E980-E325-11CE-BFC1-08002BE10318	Floppy drives
HDC	4D36E96A-E325-11CE-BFC1-08002BE10318	Hard drive controllers
HIDClass	745A17A0-74D3-11D0-B6FE-00A0C90F57DA	Some USB devices
1394	6BDD1FC1-810F-11D0-BEC7-08002BE2092F	IEEE 1394 host controller
Image	6BDD1FC6-810F-11D0-BEC7-08002BE2092F	Cameras and scanners
Keyboard	4D36E96B-E325-11CE-BFC1-08002BE10318	Keyboards
Modem	4D36E96D-E325-11CE-BFC1-08002BE10318	Modems
Mouse	4D36E96F-E325-11CE-BFC1-08002BE10318	Mice and pointing devices
Media	4D36E96C-E325-11CE-BFC1-08002BE10318	Audio and video devices
Net	4D36E972-E325-11CE-BFC1-08002BE10318	Network adapters
Ports	4D36E978-E325-11CE-BFC1-08002BE10318	Serial and parallel ports
SCSIAdapter	4D36E97B-E325-11CE-BFC1-08002BE10318	SCSI and RAID controllers
System	4D36E97D-E325-11CE-BFC1-08002BE10318	System buses, bridges, etc.
USB	36FC9E60-C465-11CF-8056-444553540000	USB host controllers and hubs

Now, there is a problem, if we remove and add device very quickly. It will not update the status in system table. So, after removing a device from PC, it shows, device is still attached. To overcome the problem, I used following code-

public static class Win32Api

    {

        public const int CM_LOCATE_DEVNODE_NORMAL = 0x00000000;

        public const int CM_REENUMERATE_NORMAL = 0x00000000;

        public const int CR_SUCCESS = 0x00000000;

        [DllImport("CfgMgr32.dll", SetLastError = true)]

        public static extern int CM_Locate_DevNodeA(ref int pdnDevInst, string pDeviceID, int ulFlags);

        [DllImport("CfgMgr32.dll", SetLastError = true)]

        public static extern int CM_Reenumerate_DevNode(int dnDevInst, int ulFlags);

    }

And use it just at the beginning of your code-

int pdnDevInst = 0;

            if (Win32Api.CM_Locate_DevNodeA(ref pdnDevInst, null, Win32Api.CM_LOCATE_DEVNODE_NORMAL) != Win32Api.CR_SUCCESS) { }

          

            if (Win32Api.CM_Reenumerate_DevNode(pdnDevInst, Win32Api.CM_REENUMERATE_NORMAL) != Win32Api.CR_SUCCESS) { }

Full code-

public static void Main()

        {

int pdnDevInst = 0;

            if (Win32Api.CM_Locate_DevNodeA(ref pdnDevInst, null, Win32Api.CM_LOCATE_DEVNODE_NORMAL) != Win32Api.CR_SUCCESS) { }

          

            if (Win32Api.CM_Reenumerate_DevNode(pdnDevInst, Win32Api.CM_REENUMERATE_NORMAL) != Win32Api.CR_SUCCESS) { }

          

            if (getDeviceFromHWM("{50DD5230-BA8A-11D1-BF5D-0000F805F530}"))

                Console.WriteLine("Card reader is connected");

}

Further reference-

http://msdn.microsoft.com/en-us/library/windows/desktop/aa394353(v=vs.85).aspx

http://library.wmifun.net/cimv2/win32_pnpentity.html

Dynamic property or Extended property in C#

I was busy to create architecture of asp.net (C#) project. In the time of development, I faced a situation where it will be good to have a dynamic property generation. I did some search, and found many examples. But after going through all, I found something, which is really nice and solve my problem. My problems are-

1>  I need to get all the data fetched from table in DB in a custom and pre-defined model in c#, but sometime DB queries can return some columns which are not in the defined properties of predefined model.

2>  When I do serialization of the model in c#, it should serialize in normal and proper way, with or without extra columns returned from DB.

Example-

Suppose, I define a model –

Public class EmpModel{

Public string EmpName{get; set;}

Public string EmpId{get; set;}

}

And I also write three SQL queries-

SELECT EmpName,EmpId,EmpAddress from tbl_Employee

SELECT EmpName,EmpId,EmpDept from tbl_Employee

SELECT EmpName,EmpId,EmpDOB from tbl_Employee

Now, as you can see, the queries are returning three columns, but the model only has two properties. I cannot manage EmpAddress, EmpDept and EmpDOB in model. As well as, the 3^rd field will be different in type also. To manage this situation, I found-

1>     AssemblyBuilder

2>     ModuleBuilder

3>     TypeBuilder

4>     FieldBuilder

5>     PropertyBuilder

6>     MethodAttributes

7>     MethodBuilder

These are the main building blocks of my solution.

The theory of the solution is, I have to create a class which will have EmpModel as a base class and with the properties (Extra properties) needed. All these, need to be done dynamically.

For all these, I managed to write two method sets(Three methods), which will handle everything for me-

MethodSet 1 (to bind DB columns with Model properties)-[Contains two methods]

public void getModelFromObject<T, T1>(object valu, ref List<T> el,Dictionary<string,Type> props) where T1 : T, new()

        {

            DataTable dt = ((DataSet)valu).Tables[0];

            Type dynamicType = getType(typeof(T).Name+ "Ext", props, typeof(T1));

            foreach (DataRow dr in ((DataSet)valu).Tables[0].Rows)

            {

                T item = (T)Activator.CreateInstance(dynamicType);

                getObject<T>(dr, ref item, dt);

                T tsts = item;

                ((List<T>)el).Add(item);

            }

        }

public void getObject<T>(DataRow dr,ref T obj, DataTable dt)

        {

          

            foreach (DataColumn dc in dt.Columns)

            {

                if (obj.GetType().GetProperty(dc.ColumnName) != null)

                {

                   

                        obj.GetType().GetProperty(dc.ColumnName).SetValue(obj, dr[dc.ColumnName], null);

                 

                }

            }

        }

MethodSet 2(to create extended properties)-[Contains one method]

  public Type getType(string dynamicClassName, Dictionary<string, Type> propertyList, Type baseClassType)

        {

            bool isNewProperties = false;

            AssemblyBuilder assemblyBilder = System.Threading.Thread.GetDomain().DefineDynamicAssembly

            (new AssemblyName(dynamicClassName + "Assembly"), AssemblyBuilderAccess.Run);

            ModuleBuilder moduleBilder = assemblyBilder.DefineDynamicModule(dynamicClassName + "Module");

            TypeBuilder typeBilder = moduleBilder.DefineType(dynamicClassName, TypeAttributes.Public | TypeAttributes.Class, baseClassType);

            string propertyName = null;

            Type propertyType = null;

            var baseClassObj = Activator.CreateInstance(baseClassType);

            foreach (var prop in propertyList)

            {

                propertyName = prop.Key;

                propertyType = prop.Value;

                var propExist = baseClassObj.GetType().GetProperty(propertyName);

                if (propExist != null)

                {

                    continue;

                }

                FieldBuilder filedBilder = typeBilder.DefineField("_" + propertyName, propertyType, FieldAttributes.Private);

                PropertyBuilder propertyBilder = typeBilder.DefineProperty(propertyName, System.Reflection.PropertyAttributes.None, propertyType,

                            new Type[] { propertyType });

               

                MethodAttributes GetSetAttr = MethodAttributes.Public | MethodAttributes.HideBySig;

                MethodBuilder currGetPropMthdBilder = typeBilder.DefineMethod("geter", GetSetAttr, propertyType, null);

                ILGenerator currtGetIL = currGetPropMthdBilder.GetILGenerator();

                currtGetIL.Emit(OpCodes.Ldarg_0);

                currtGetIL.Emit(OpCodes.Ldfld, filedBilder);

                currtGetIL.Emit(OpCodes.Ret);

                MethodBuilder currSetPropMthdBilder = typeBilder.DefineMethod("seter", GetSetAttr, null, new Type[] { propertyType });

                ILGenerator currSetIL = currSetPropMthdBilder.GetILGenerator();

                currSetIL.Emit(OpCodes.Ldarg_0);

                currSetIL.Emit(OpCodes.Ldarg_1);

                currSetIL.Emit(OpCodes.Stfld, filedBilder);

                currSetIL.Emit(OpCodes.Ret);

                propertyBilder.SetGetMethod(currGetPropMthdBilder);

                propertyBilder.SetSetMethod(currSetPropMthdBilder);

                isNewProperties = true;

            }

            if (isNewProperties == false)

            {

                return baseClassType;

            }

            return typeBilder.CreateType();

        }

And now, the use of these methods-

     List<IEmp> obj = new List<IEmp>();

            Dictionary<string, Type> props= new Dictionary<string, Type>();

            props.Add("EmpAddress", typeof(string));//if more then one add more.

            modelPlatform.init().getModelFromObject<IEmp,Emp>(ds, ref obj, val);//ds- is the dataset returned from DB

           

            return obj;

Same for two other queries also.

That’s it, Enjoy.