CDeviceTree

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• Download demo project - 19.8 Kb

Introduction

Here we want to show installed devices of our PC like what a Device Manager shows. In Device Manager, installed devices are shown in specific categories like: DVD/CD-ROM Drives or Floppy disk controllers. In my previous article Enumerate Installed Devices Using Setup API, I show you how we can list all devices. In this article, installed devices are shown in a tree in their categories, like Device Manager.

For this purpose, I created a new class called CDeviceTree that is inherited from CTreeCtrl. Using of the new class is very simple.

How to use

First of all add DeviceTree.h and DeviceTree.cpp files to your project. Then in your dialog resource editor, add new Tree control (figure 2 shows it). Rename the control ID to your desired ID, for example IDC_DEVICE_TREE. Run class wizard (Ctrl+W) and add new member variable with variable type CDeviceTree. (If CDeviceTree does not appear in combo box, choose CTreeCtrl, then in your dialog header file, rename CTreeCtrl to CDeviceTree). Name it as m_DeviceTree.

Figure 2 - Add new tree control to dialog resource

Figure 3- Add member variable with variable type CDeviceTree.

If CDeviceTree does not appear in Variable type combo box, simply choose CTreeCtrl, then rename it to CDeviceTree in your dialog header file. For example:

CTreeCtrl   m_DeviceTree;

to:

CDeviceTree   m_DeviceTree;

Don't forget to include DeviceTree.h to your dialog header file. OK, now everything is ready to compile!

CDeviceTree Class

The CDeviceTree class contains only one public member function: EnumDevices(). The function is responsible for enumerating all of the installed devices in their categories. The user must only use this function to see the tree of devices. The best way for this is OnInitDialog() member function of main dialog. In other hand:

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

    // 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_DeviceTree.EnumDevices();   //CDeviceTree will enumerate all of devices
    
    return TRUE;  // return TRUE  unless you set the focus to a control
}

The class definition is as below:

#ifndef _DEVICE_TREE_H_
#define _DEVICE_TREE_H_

#include "SetupAPI.h"
#include "cfgmgr32.h"

class CDeviceTree : public CTreeCtrl
{
// Construction
public:
    CDeviceTree();

// Implementation
public:
    void EnumDevices();
    virtual ~CDeviceTree();

private:
    int EnumDevices(int index, TCHAR* DeviceClassName, TCHAR* DeviceName);
    int EnumDeviceClasses(int index, TCHAR* DeviceClassName, 
              TCHAR* DeviceClassDesc, BOOL* DevicePresent, int* ClassImage);
    
    SP_CLASSIMAGELIST_DATA m_ImageListData;
    CImageList m_ImageList;
    
    // Generated message map functions
protected:
    //{{AFX_MSG(CDeviceTree)
        // NOTE - the ClassWizard will add and remove member functions here.
    //}}AFX_MSG

    DECLARE_MESSAGE_MAP()
};

#endif // _DEVICE_TREE_H_

As you see, the application shows devices like Device Manager does (Figure 4):

Enjoy!