. Net-diving into system programming-Part 1 [posting]

Using system;
Using system. runtime. interopservices;
Using system. text;

Namespace devclasses
{
/// <Summary>
/// Summary description for class.
/// </Summary>
Class deviceclasses
{
/// <Summary>
/// The main entry point for the application.
/// </Summary>
Public const int max_name_ports = 7;
Public const int regdisposition_openexisting = (0x00000001 );
// Open key only if exists
Public const int cm_registry_hardware = (0x00000000 );

Public const int cr_success = (0x00000000 );
Public const int cr_no_such_value = (0x00000025 );
Public const int cr_invalid_data = (0x0000001f );
Public const int digcf_present = (0x00000002 );
Public const int diocr_installer = (0x00000001 );
// Maximumallowed access type to Reg.
Public const int maximum_allowed = (0x02000000 );
[Structlayout (layoutkind. Sequential)]

Public class sp_devinfo_data
{
Public int cbsize;
Public guid classguid;
Public int devinst; // devinst handle
Public ulong reserved;
};

[Dllimport ("cfgmgr32.dll")]
Public static extern uint32
Cm_open_devnode_key (intptr dndevnode, uint32 samdesired,
Uint32 ulhardwareprofile,
Uint32 disposition, intptr phkdevice, uint32 ulflags );

[Dllimport ("cfgmgr32.dll")]
Public static extern uint32
Cm_enumerate_classes (uint32 classindex, ref guid classguid, uint32 Params );

[Dllimport ("setupapi. dll")] //
Public static extern Boolean
Setupdiclassnamefromguida (ref guid classguid,
Stringbuilder classname, // char *?
Uint32 classnamesize, ref uint32 requiredsize );

[Dllimport ("setupapi. dll")]
Public static extern intptr
Setupdigetclassdevsa (ref guid classguid, uint32 enumerator,
Intptr hwndparent, uint32 flags );

[Dllimport ("setupapi. dll")]
Public static extern Boolean
Setupdienumdeviceinfo (intptr deviceinfoset, uint32 memberindex,
Ref sp_devinfo_data deviceinfodata );

[Dllimport ("setupapi. dll")]
Public static extern Boolean
Setupdidestroydeviceinfolist (intptr deviceinfoset );

[Dllimport ("setupapi. dll")]
Public static extern intptr
Setupdigetclassdevsa (ref guid classguid, uint32 samdesired,
Uint32 flags, ref string hwndparent, intptr reserved );

[Dllimport ("setupapi. dll")]
Public static extern intptr
Setupdiopenclassregkeyexa (
Ref guid classguid, uint32 samdesired, int flags, intptr machinename,
Uint32 reserved );

[Dllimport ("advapi32.dll")]
Public static extern uint32
Regqueryvaluea (intptr keyclass, uint32 subkey,
Stringbuilder classdescription, ref uint32 sizeb );

[Dllimport ("user32.dll")]
Public static extern Boolean
Chartooem (string lpszsrc, stringbuilder lpszdst );

Public static int enumerateclasses (uint32 classindex,
Ref stringbuilder classname, stringbuilder classdescription,
Ref bool devicepresent)
{
Guid classguid = guid. empty;
Intptr newdeviceinfoset;
Sp_devinfo_data deviceinfodata;
Uint32 result;
Stringbuilder name = new stringbuilder ("");
Bool resnam = false;
Uint32 requiredsize = 0;

Intptr;

Result = cm_enumerate_classes (classindex, ref classguid, 0 );

Classname = new stringbuilder ("");
Devicepresent = false;
// Incorrect device class:
If (result = cr_invalid_data)
{
Return-2;
}
// Device class is absent
If (result = cr_no_such_value)
{
Return-1;
}
// Bad Param.-fatal error
If (result! = Cr_success)
{
Return-3;
}

Name. capacity = 0;
Resnam = setupdiclassnamefromguida (ref classguid, name, requiredsize,
Ref requiredsize );
If (requiredsize> 0)
{
Name. capacity = (INT) requiredsize;
Resnam = setupdiclassnamefromguida (ref classguid, name,
Requiredsize, ref requiredsize );
}

Newdeviceinfoset = setupdigetclassdevsa (
Ref classguid,
0,
Intptr. Zero,
Digcf_present );

If (newdeviceinfoset. toint32 () =-1)
{Devicepresent = false;
Classname = Name;
Return 0 ;}

Intptr keyclass = setupdiopenclassregkeyexa (
Ref classguid, maximum_allowed, diocr_installer, intptr. Zero, 0 );
If (keyclass. toint32 () =-1)
{Devicepresent = false;
Classname = Name;
Return 0 ;}

Uint32 sizeb = 1000;
String ABCD = "";
Stringbuilder Cd = new stringbuilder ("");
Classdescription. capacity = 1000;

Uint32 res = regqueryvaluea (keyclass, 0, classdescription, ref sizeb );

If (res! = 0) classdescription = new stringbuilder ("");
Setupdidestroydeviceinfolist (newdeviceinfoset );
Classname = Name;
Devicepresent = true;

Return 0;

}

[Stathread]
Static void main (string [] ARGs)
{
Stringbuilder classes = new stringbuilder ("");
Stringbuilder classesdescr = new stringbuilder ("");

Stringbuilder classesdescroem = new stringbuilder ("");
Classesdescroem. capacity = 1000;
Boolean devexist = false;
Uint32 I = 0;
While (true)
{
Int res = enumerateclasses (I, ref classes, classesdescr, ref devexist );
If (RES =-1) break;
++ I;
If (RES <-1 |! Devexist) continue;
Console. writeline ("classname = {0}, description = {1}", classes, classesdescr );
}
Return;
}
}
}