mfc Dockable control bars (panes) Docking pane to the left side of frame.

Example

// Main frame class declaration
class CMainFrame 
   : public CMDIFrameWndEx
{
    DECLARE_DYNAMIC(CMainFrame)

protected:
    // declare our pane
    CDockablePane m_wndPane;

    // .... other class memebers

public:
    CMainFrame();

protected:
    afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
    DECLARE_MESSAGE_MAP()
};


// Main frame class implementation
IMPLEMENT_DYNAMIC(CMainFrame, CMDIFrameWndEx)

BEGIN_MESSAGE_MAP(CMainFrame, CMDIFrameWndEx)
    ON_WM_CREATE()
END_MESSAGE_MAP()

CMainFrame::CMainFrame()
{
}

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CMDIFrameWndEx::OnCreate(lpCreateStruct) == -1)
        return -1;

    // enable frame docking to any sides
    EnableDocking(CBRS_ALIGN_ANY);

    // set the visual manager used to draw all user interface elements
    CMFCVisualManager::SetDefaultManager(RUNTIME_CLASS(CMFCVisualManagerWindows));

    // enable smart docking style window behavior
    CDockingManager::SetDockingMode(DT_SMART);


    // Other frame initialization code
    // ....


    // Creating the pane.
    // ID_VIEW_PANE_ID - pane ID, must be declared in resource.h
    // CRect(0, 0, 100, 100) - default pane size in floating state (pane is not docked to any frame sides).
    // CBRS_LEFT - default side for pane docking.
    if (!m_wndPane.Create(_T("My Pane"), this, CRect(0, 0, 100, 100), TRUE, ID_VIEW_PANE_ID, WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_CLIPCHILDREN | CBRS_LEFT | CBRS_FLOAT_MULTI)) {
        TRACE0("Failed to create Pane\n");
        return -1; // failed to create
    }
    // Enable docking and redocking pane to frame any sides (you can pass a combination of CBRS_ALIGN_ flags)
    m_wndPane.EnableDocking(CBRS_ALIGN_ANY);

    // Dock pane to the default (left) side of the frame.
    DockPane(&m_wndPane);

    return 0;
}