场景

在做Win32/WTL开发时，CListViewCtrl控件是常用的表格控件。有时候自绘listview时，需要在单元格上绘制小图标，并且小图标能响应鼠标点击的操作。那么如何实现判断是否点击了小图标呢？

说明

要响应点击单元格上的小图标，那么需要判断点击的坐标POINT是否在小图标的区域CRect里。坐标很容易得到，点击消息都会带坐标值。小图标区域需要获取单元格所在区域，之后在通过相对位置获取小图标的区域。也就是只要获取点击的单元格区域就可以获取小图标区域。所以下边来看看如何获取点击的单元格所在区域。
listview要响应点击操作，可以使用传统的WM_LBUTTONUP消息，也可以使用NM_CLICK通知。
如果是响应WM_LBUTTONUP消息，可以使用CListViewCtrl.SubItemHitTest()方法，它通过鼠标点击坐标来计算所在的行和列数值nItem和info.iSubItem^[3]。
```
LVHITTESTINFO info = {0};
info.pt = lpnmlv->ptAction;
auto nItem = listview_.SubItemHitTest(&info);
```
如果是响应NM_CLICK通知，它的lParam就可以强制转换为LPNMITEMACTIVATE指针类型^[2]。这个类型里可以使用它的成员iItem行,iSubItem列和ptAction点击坐标。通过行和列值可以通过listview方法GetSubItemRect获取所在单元格的区域^[1]。注意：这个方法只能获取第一列以上的区域，传递第0列获取的是整行的区域，所以要获取第0列的区域，还需要使用方法GetColumnWidth(0)来进行换算。

listview_.GetSubItemRect(p->iItem,p->iSubItem,LVIR_BOUNDS,&rect); // 第1列以上
if(!p->iSubItem){
	// 第0列计算
	auto width = listview_.GetColumnWidth(0);
	rect.right = rect.left+width; 
}

例子

View.h

// View.h : interface of the CView class
//
/

#pragma once

#include <utility>
#include <string>


enum
{
	kMyStaticId = WM_USER+1,
	kMyListViewId,
	kMyCheckListViewId,
	kMySortListViewId,
	kMyButtonId
};

class CView : public CWindowImpl<CView>
{
public:
	DECLARE_WND_CLASS(NULL)

	BOOL PreTranslateMessage(MSG* pMsg);

	BEGIN_MSG_MAP_EX(CView)
		MSG_WM_CREATE(OnCreate)
		MESSAGE_HANDLER(WM_PAINT, OnPaint)
		NOTIFY_HANDLER(kMyListViewId,NM_CLICK,OnNMClickListResult)
		NOTIFY_HANDLER(kMyListViewId,LVN_HOTTRACK,OnListItemHotTrack)
		REFLECT_NOTIFICATIONS()
	END_MSG_MAP()

// Handler prototypes (uncomment arguments if needed):
//	LRESULT MessageHandler(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
//	LRESULT CommandHandler(WORD /*wNotifyCode*/, WORD /*wID*/, HWND /*hWndCtl*/, BOOL& /*bHandled*/)
//	LRESULT NotifyHandler(int /*idCtrl*/, LPNMHDR /*pnmh*/, BOOL& /*bHandled*/)
	int OnCreate(LPCREATESTRUCT lpCreateStruct);
	LRESULT OnPaint(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/);
	void UpdateLayout();
	LRESULT OnNMClickListResult(int idCtrl,LPNMHDR pnmh,BOOL &bHandled);
	void AddMockData(CListViewCtrl& listview);
	void OnCommandIDHandlerEX(UINT uNotifyCode, int nID, CWindow wndCtl);
	LRESULT OnListItemHotTrack(int idCtrl,LPNMHDR pnmh,BOOL &bHandled);

private:
	std::wstring GetControlText(HWND hwnd,wchar_t* buf = NULL);

	CListViewCtrl listview_;

	CFont font_normal_;
	CFont font_bold_;

	CBrushHandle brush_white_;
	CBrushHandle brush_hollow_;
	CBrush brush_red_;
	CToolTipCtrl tooltip_;
	TCHAR strToolTipText_[MAX_PATH];

public:
};

View.cpp

// View.cpp : implementation of the CView class
//
/

#include "stdafx.h"
#include "resource.h"
#include <utility>
#include <sstream>
#include <assert.h>

#include "View.h"
#include <CommCtrl.h>
#include <string>
#include <regex>

using namespace std;

BOOL CView::PreTranslateMessage(MSG* pMsg)
{
	return FALSE;
}

LRESULT CView::OnPaint(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
{
	CPaintDC dc(m_hWnd);
	CMemoryDC mdc(dc,dc.m_ps.rcPaint);

	CRect rect_client;
	GetClientRect(&rect_client);
	mdc.FillSolidRect(rect_client,RGB(255,255,255));
	//TODO: Add your drawing code here

	return 0;
}

static HFONT GetFont(int pixel,bool bold,const wchar_t* font_name)
{
	LOGFONT lf; 
	memset(&lf, 0, sizeof(LOGFONT)); // zero out structure 
	lf.lfHeight = pixel; // request a 8-pixel-height font
	if(bold)
	{
		lf.lfWeight = FW_BOLD;  
	}
	lstrcpy(lf.lfFaceName, font_name); // request a face name "Arial"
	
	HFONT font = ::CreateFontIndirect(&lf);
	return font;
}


std::wstring CView::GetControlText(HWND hwnd,wchar_t* buf)
{
	auto length = ::GetWindowTextLength(hwnd);
	bool bufNull = false;
	if(!buf){
		buf = new wchar_t[length+1]();
		bufNull = true;
	}
	
	::GetWindowText(hwnd,buf,length+1);
	std::wstring str(buf);

	if(bufNull)
		delete []buf;

	return str;
}

static std::wstring GetProductBinDir()
{
	static wchar_t szbuf[MAX_PATH];  
	GetModuleFileName(NULL,szbuf,MAX_PATH);  
    PathRemoveFileSpec(szbuf);
	int length = lstrlen(szbuf);
	szbuf[length] = L'\\';
	szbuf[length+1] = 0;
	return std::wstring(szbuf);
}

LRESULT CView::OnNMClickListResult(int idCtrl,LPNMHDR pnmh,BOOL &bHandled)
{
	auto p = (LPNMITEMACTIVATE) pnmh;
	int row = p->iItem;
	if(row == -1)
		return 0;
	
	CRect rect;
	// The one-based index of the subitem.
	// LVM_GETSUBITEMRECT message (Commctrl.h) - Win32 apps | Microsoft Learn https://learn.microsoft.com/en-us/windows/win32/controls/lvm-getsubitemrect
	listview_.GetSubItemRect(p->iItem,p->iSubItem,LVIR_BOUNDS,&rect);
	if(!p->iSubItem){
		auto width = listview_.GetColumnWidth(0);
		rect.right = rect.left+width;
	}

	auto header = listview_.GetHeader();
	int nColumnCount = header.GetItemCount();
	wstringstream wss;
	static wchar_t buf[MAX_PATH];
	memset(buf,0,sizeof(buf));
	listview_.GetItemText(row,p->iSubItem,buf,MAX_PATH);
	
	wss << buf << L": Rect:[" << 
		rect.left << L"," << 
		rect.top << L"," <<
		rect.Width() << L"," <<
		rect.Height() << L"] Position:[" << 
		p->ptAction.x << L"," << p->ptAction.y << L"]";
	wstring result = wss.str();

	MessageBox(result.c_str());
	return 0;
}

void CView::AddMockData(CListViewCtrl& listview)
{
	listview.InsertColumn(0,L"No.",LVCFMT_LEFT,40);
	listview.InsertColumn(1,L"Name",LVCFMT_LEFT,200);
	listview.InsertColumn(2,L"Website",LVCFMT_LEFT,200);
	listview.InsertColumn(3,L"Level",LVCFMT_LEFT,200);

	wchar_t buf[MAX_PATH] = {0};
	LVCOLUMN co;
	memset(&co,0,sizeof(co));
	co.mask = LVCF_TEXT;
	co.pszText = buf;
	co.cchTextMax = MAX_PATH;
	listview.GetColumn(1,&co);
	std::wstring c0Text(buf);

	listview.GetColumn(2,&co);
	std::wstring c1Text(buf);
	
	listview.GetColumn(3,&co);
	std::wstring c2Text(buf);

	for(int i = 0; i<10;++i){
		
		wsprintf(buf,L"%d",i+1);
		listview.AddItem(i,0,buf);

		wsprintf(buf,(c0Text+L"-%d").c_str(),i);
		listview.AddItem(i,1,buf);

		wsprintf(buf,(c1Text+L"-%d").c_str(),i);
		listview.AddItem(i,2,buf);

		wsprintf(buf,(c2Text+L"-%d").c_str(),i);
		listview.AddItem(i,3,buf);
	}
}

LRESULT CView::OnListItemHotTrack(int idCtrl,LPNMHDR pnmh,BOOL &bHandled)
{
	bHandled = TRUE;
	LPNMLISTVIEW lpnmlv = (LPNMLISTVIEW) pnmh;
	
	// 获取坐标所在的Item(行)和SubItem(列).
	LVHITTESTINFO info = {0};
	info.pt = lpnmlv->ptAction;
	auto nItem = listview_.SubItemHitTest(&info);
	if(nItem == -1)
		return 0;

	static int kShowTooltipColumn = 2;
	static wchar_t buf[MAX_PATH] = {0};
	if(info.iSubItem == kShowTooltipColumn){
		listview_.GetItemText(nItem,info.iSubItem,buf,MAX_PATH);
		tooltip_.UpdateTipText(buf,listview_);

		if(!listview_.GetToolTips()) 
			listview_.SetToolTips(tooltip_);
	}else{
		if(listview_.GetToolTips())
			listview_.SetToolTips(NULL);
	}

	return 0;
}

int CView::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
	font_normal_ = ::GetFont(16,false,L"Arial");
	font_bold_ = ::GetFont(16,true,L"Arial");

	// 1.创建CListViewCtrl
	listview_.Create(m_hWnd,0,NULL,WS_CHILD | WS_TABSTOP |WS_VISIBLE
		|LVS_ALIGNLEFT|LVS_REPORT|LVS_SHOWSELALWAYS|WS_BORDER,0,kMyListViewId);
	// 2.如果需要监听在listview鼠标移动消息，创建时传入LVS_EX_TRACKSELECT扩展样式。
	listview_.SetExtendedListViewStyle(LVS_EX_FULLROWSELECT|LVS_EX_GRIDLINES|LVS_EX_DOUBLEBUFFER|LVS_EX_TRACKSELECT);
	listview_.SetFont(font_normal_);
	auto header = listview_.GetHeader();
	header.SetFont(font_bold_);
	listview_.SetBkColor(RGB(255,255,255));
	AddMockData(listview_);

	tooltip_.Create(listview_,NULL,NULL,TTS_NOPREFIX);
	tooltip_.AddTool(listview_,L"");
	listview_.SetToolTips(tooltip_);
	listview_.SetHoverTime(10);

	brush_hollow_ = AtlGetStockBrush(HOLLOW_BRUSH);
	brush_white_ = AtlGetStockBrush(WHITE_BRUSH);
	brush_red_.CreateSolidBrush(RGB(255,0,0));
	UpdateLayout();

	return 0;
}

void CView::OnCommandIDHandlerEX(UINT uNotifyCode, int nID, CWindow wndCtl)
{
		
}

void CView::UpdateLayout()
{
	CRect rect;
	GetClientRect(&rect);

	CClientDC dc(m_hWnd);
	dc.SelectFont(font_normal_);

	CSize size_control(700,300);
	CRect rect_control = CRect(CPoint(20,20),size_control);
	listview_.MoveWindow(rect_control);

}