How to redraw the header of CListCtrl in MFC

MFC Medium CListCtrl It is actually composed of two controls , One is the header control , One is list control . Sometimes , We need to redraw the header , Make it meet the requirements of specific scenarios .
This paper introduces CListCtrl Redrawing method of header , The effect of custom header is as follows .

One 、 from CHeaderCtrl Derive a custom header class CCustomHeader

MFC The class representing the header control in is CHeaderCtrl, We derive a new class from it CCustomHeader .
The header file is ：

class CCustomHeader : public CHeaderCtrl
{
    
	DECLARE_DYNAMIC(CCustomHeader)

public:
	CCustomHeader();
	virtual ~CCustomHeader();
	// Set the alignment of header cells , See DrawText Text alignment format in function 
	void SetTextAlign(UINT uFormat = DT_CENTER | DT_SINGLELINE | DT_VCENTER);

protected:
	virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
	DECLARE_MESSAGE_MAP()

private:
	UINT m_nTextAlignFormat;	// Heading text alignment 
};

Implementation file

// CCustomHeader.cpp:  Implementation file 
//

#include "pch.h"
#include "TestCustomHeader.h"
#include "CCustomHeader.h"


// CCustomHeader

IMPLEMENT_DYNAMIC(CCustomHeader, CHeaderCtrl)

CCustomHeader::CCustomHeader()
	:m_nTextAlignFormat(DT_CENTER | DT_SINGLELINE | DT_VCENTER)
{
    }

CCustomHeader::~CCustomHeader()
{
    }

void CCustomHeader::SetTextAlign(UINT uFormat)
{
    
	m_nTextAlignFormat = uFormat;
}

BEGIN_MESSAGE_MAP(CCustomHeader, CHeaderCtrl)
END_MESSAGE_MAP()

void CCustomHeader::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
    
	ASSERT(lpDrawItemStruct->CtlType == ODT_HEADER);
	HDITEM hdi;
	TCHAR  lpBuffer[256];

	hdi.mask = HDI_TEXT;
	hdi.pszText = lpBuffer;
	hdi.cchTextMax = 256;
	GetItem(lpDrawItemStruct->itemID, &hdi);

	CDC* pDC;
	pDC = CDC::FromHandle(lpDrawItemStruct->hDC);
	HGDIOBJ hOldFont = pDC->SelectObject(GetStockObject(DEFAULT_GUI_FONT));
	
	//  Draw the button border 
	::DrawFrameControl(lpDrawItemStruct->hDC, &lpDrawItemStruct->rcItem, DFC_BUTTON, DFCS_BUTTONPUSH);

	// Draw text 
	::DrawText(lpDrawItemStruct->hDC, lpBuffer, _tcslen(lpBuffer),
		&lpDrawItemStruct->rcItem, m_nTextAlignFormat);

	pDC->SelectObject(hOldFont);
}

Please note that , In the implementation file , We rewrote DrawItem Virtual functions ; Therefore, when the header control is self drawn , Called every time you draw DrawItem function , In this function, we get the... Of the header control DC, Then you can draw .
Please also note that in DrawItem The following functions used in ：

BOOL GetItem( int nPos, HDITEM* pHeaderItem ) const;
explain ： This function can get the information of each item of the header control （Retrieves information about a header control item.）

Using this function , We get the title content of each item in the header .

Two 、 Use custom header class CCustomHeader

Create a dialog based program , Add ：

	CListCtrl m_wndLstMain;		// Represents the list control itself 
	CCustomHeader m_wndHeader;	// The header control that represents the list control 

stay OnInitDialog Add to function ：

BOOL CTestDlg::OnInitDialog()
{
    
	//....  Omit 
	
	// TODO:  Add additional initialization code here 
	CRect rect;
	m_wndLstMain.GetClientRect(rect);
	m_wndLstMain.InsertColumn(0, _T(" full name "), LVCFMT_LEFT, rect.Width() / 3);
	m_wndLstMain.InsertColumn(1, _T(" class "), LVCFMT_LEFT, rect.Width() / 3);
	m_wndLstMain.InsertColumn(2, _T(" Student number "), LVCFMT_LEFT, rect.Width() / 3);

	m_wndLstMain.InsertItem(0, _T(" Zhang San "));
	m_wndLstMain.SetItemText(0, 1, _T(" Class one "));
	m_wndLstMain.SetItemText(0, 2, _T("001"));

	m_wndLstMain.InsertItem(1, _T(" Li Si "));
	m_wndLstMain.SetItemText(1, 1, _T(" Class one "));
	m_wndLstMain.SetItemText(1, 2, _T("002"));

	m_wndLstMain.InsertItem(2, _T(" Wang Wu "));
	m_wndLstMain.SetItemText(2, 1, _T(" Class one "));
	m_wndLstMain.SetItemText(2, 2, _T("003"));

	m_wndLstMain.SetExtendedStyle(LVS_EX_GRIDLINES);
	
	// Subclass the header of the list control 
	CHeaderCtrl* pHeader = m_wndLstMain.GetHeaderCtrl();
	if(pHeader)
		m_wndHeader.SubclassWindow(pHeader->GetSafeHwnd());
	HDITEM hdItem;
	hdItem.mask = HDI_FORMAT;
	for (int i = 0; i < m_wndHeader.GetItemCount(); i++)
	{
    
		m_wndHeader.GetItem(i, &hdItem);
		hdItem.fmt |= HDF_OWNERDRAW;	// Add self drawing style 
		m_wndHeader.SetItem(i, &hdItem);
	}
	
	//....  Omit 
}

Note in the above function , We first initialize CListCtrl object , Created multiple columns and children , And then use it GetHeaderCtrl() The function found CListCtrl Object's header control , Last call SubclassWindow Subclass the header control and bind it to m_wndHeader( This is our overridden header control class object ).
however , That's not the end , We need to change every item in the header to self drawn style , such , Only when the header is redrawn DrawItem function , The specific code is ：

	HDITEM hdItem;
	hdItem.mask = HDI_FORMAT;
	for (int i = 0; i < m_wndHeader.GetItemCount(); i++)
	{
    
		m_wndHeader.GetItem(i, &hdItem);
		hdItem.fmt |= HDF_OWNERDRAW;	// Add self drawing style 
		m_wndHeader.SetItem(i, &hdItem);
	}