Getting Information from WMI in Visual C++

// Using WMIDlg.cpp : implementation file
//

#include "stdafx.h"
#include "Using WMI.h"
#include "Using WMIDlg.h"
#include "wbemidl.h"
#include <comdef.h>

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CUsingWMIDlg dialog

CUsingWMIDlg::CUsingWMIDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CUsingWMIDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CUsingWMIDlg)
		// NOTE: the ClassWizard will add member initialization here
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CUsingWMIDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CUsingWMIDlg)
	// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
	DDX_Control(pDX, IDC_PROGRESS1, m_progressCtrl);
}

BEGIN_MESSAGE_MAP(CUsingWMIDlg, CDialog)
	//{{AFX_MSG_MAP(CUsingWMIDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BUTTON_GETINFO, OnButtonGetinfo)
	ON_MESSAGE( WM_USER+1, OnUpdateSlider)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CUsingWMIDlg message handlers

BOOL CUsingWMIDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	m_progressCtrl.SetRange(0, 100);
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CUsingWMIDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CUsingWMIDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CUsingWMIDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

UINT GetProcessorLoad( LPVOID pParam )
{
	CUsingWMIDlg* dlg = (CUsingWMIDlg*)pParam;
	
	CoInitialize(NULL);

	HRESULT hRes = CoInitializeSecurity( NULL, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_PKT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL,
							EOAC_NONE, 0);

	if(hRes != S_OK) return 0;

	CComPtr<IWbemLocator> pIWbemLocator;
	CComPtr<IWbemServices> pIWbemServices;
	CComPtr<IEnumWbemClassObject> pIEnumObject;

	CComBSTR bstrNamespace(_T("root\\cimv2"));

	hRes = pIWbemLocator.CoCreateInstance(CLSID_WbemAdministrativeLocator);
	if(hRes != S_OK) return 0;

	hRes = pIWbemLocator->ConnectServer(bstrNamespace, NULL, NULL, NULL, 0, NULL, NULL, &pIWbemServices);
	if(hRes != S_OK) return 0;

	while(true)
	{
		CComBSTR bstrQuery(_T("Select * from Win32_Processor"));
		CComBSTR bstrQL(_T("WQL"));

		hRes = pIWbemServices->ExecQuery(bstrQL, bstrQuery, WBEM_FLAG_RETURN_IMMEDIATELY, NULL, &pIEnumObject);

		ULONG uCount = 1, uReturned;
		CComPtr<IWbemClassObject> pIClassObject;

		hRes = pIEnumObject->Reset();

		hRes = pIEnumObject->Next(WBEM_INFINITE, uCount, &pIClassObject, &uReturned);

		if(hRes != S_OK) return 0;

		CComVariant var;

		CComBSTR bstrProp(_T("LoadPercentage"));

		hRes = pIClassObject->Get(bstrProp, 0, &var, NULL, NULL);
		if(hRes != S_OK) return 0;

		int * value = new int(var.lVal);
		dlg->PostMessage(WM_USER+1, (WPARAM) value);
		
		pIEnumObject.Release();
	}
	return 1;
}

LRESULT CUsingWMIDlg::OnUpdateSlider(WPARAM wParam, LPARAM lParam)
{
	int* value = (int*) wParam;
	m_progressCtrl.SetPos(*value);
	
	delete value;
	return 0;
}


void CUsingWMIDlg::OnButtonGetinfo() 
{
	// TODO: Add your control notification handler code here
	AfxBeginThread(GetProcessorLoad, (LPVOID)this);
}