通过线程传递消息

今天讲一下线程如何向对话框传递消息，步骤如下：

1. 创建消息数,在xxDlg.h: #define WM_RESPONSE WM_USER+1 
2. 声明消息函数成员函数xxDlg.h: afx_msg LRESULT winMessageFun(WPARAM wParam, LPARAM lParam); （注意返回值类型为LRESULT,在VC里可以是void 类，但在vs内会提示不兼容，只能用LRESULT）
3. 添加消息映像xxDlg.cpp: ON_MESSAGE(WM_RESPONSE,winMessageFun) 
4. 定义消息响应函数xxxDlg.cpp:

   LRESULT CMFCApplicationThresdDlg::winMessageFun(WPARAM wParam, LPARAM lParam)
   {
       UNREFERENCED_PARAMETER(wParam);
       UNREFERENCED_PARAMETER(lParam);
       WORD value = lParam;
       CString str;
       str.Format(_T("%d
   "), value);
       m_edit1 += str;
       UpdateData(FALSE);
       return 0;
   }

5. 定义线程传递参数结构体

   struct ThreadParam
   {
       HWND ThreadID;
       WORD ThreadVal;
   };

6. 创建线程，在点击按键后启动线程：

   void CMFCApplicationThresdDlg::Btn_Clicked_Start()
   {
       // TODO: Add your control notification handler code here
       ThreadParam *pRecvParam = new ThreadParam;
       pRecvParam->ThreadVal = 0;
       pRecvParam->ThreadID = m_hWnd;
       //create thread
       HANDLE hThread = CreateThread(NULL, 0, ThreadProc, (LPVOID)pRecvParam, 0, NULL);
   }

7. 声明线程函数xxDlg.h: 

   private:
       static DWORD WINAPI ThreadProc(LPVOID lpParameter);

8. 定义线程函数：

   DWORD CMFCApplicationThresdDlg::ThreadProc(LPVOID lpParameter)
   {
       WORD value = ((ThreadParam*)lpParameter)->ThreadVal;
       HWND hwnd = ((ThreadParam*)lpParameter)->ThreadID;
       while (1)
       {
           value++;
           ::PostMessage(hwnd, WM_RESPONSE, 0, (LPARAM)value);
           Sleep(1000);
       }
       return 0;
   }

9. 源码：

   // MFCApplicationThresdDlg.cpp : implementation file
   //
   
   #include "stdafx.h"
   #include "MFCApplicationThresd.h"
   #include "MFCApplicationThresdDlg.h"
   #include "afxdialogex.h"
   
   #ifdef _DEBUG
   #define new DEBUG_NEW
   #endif
   
   
   // CAboutDlg dialog used for App About
   
   class CAboutDlg : public CDialogEx
   {
   public:
       CAboutDlg();
   
   // Dialog Data
       enum { IDD = IDD_ABOUTBOX };
   
       protected:
       virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
   
   // Implementation
   protected:
       DECLARE_MESSAGE_MAP()
   };
   
   CAboutDlg::CAboutDlg() : CDialogEx(CAboutDlg::IDD)
   {
   }
   
   void CAboutDlg::DoDataExchange(CDataExchange* pDX)
   {
       CDialogEx::DoDataExchange(pDX);
   }
   
   BEGIN_MESSAGE_MAP(CAboutDlg, CDialogEx)
   END_MESSAGE_MAP()
   
   
   // CMFCApplicationThresdDlg dialog
   
   
   
   CMFCApplicationThresdDlg::CMFCApplicationThresdDlg(CWnd* pParent /*=NULL*/)
       : CDialogEx(CMFCApplicationThresdDlg::IDD, pParent)
       , m_edit1(_T(""))
   {
       m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
   }
   
   void CMFCApplicationThresdDlg::DoDataExchange(CDataExchange* pDX)
   {
       CDialogEx::DoDataExchange(pDX);
       DDX_Text(pDX, IDC_EDIT1, m_edit1);
   }
   
   BEGIN_MESSAGE_MAP(CMFCApplicationThresdDlg, CDialogEx)
       ON_WM_SYSCOMMAND()
       ON_WM_PAINT()
       ON_WM_QUERYDRAGICON()
       ON_BN_CLICKED(IDC_BUTTON1, &CMFCApplicationThresdDlg::Btn_Clicked_Start)
       ON_MESSAGE(WM_RESPONSE,winMessageFun)
   END_MESSAGE_MAP()
   
   
   // CMFCApplicationThresdDlg message handlers
   
   BOOL CMFCApplicationThresdDlg::OnInitDialog()
   {
       CDialogEx::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)
       {
           BOOL bNameValid;
           CString strAboutMenu;
           bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX);
           ASSERT(bNameValid);
           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
   
       return TRUE;  // return TRUE  unless you set the focus to a control
   }
   
   void CMFCApplicationThresdDlg::OnSysCommand(UINT nID, LPARAM lParam)
   {
       if ((nID & 0xFFF0) == IDM_ABOUTBOX)
       {
           CAboutDlg dlgAbout;
           dlgAbout.DoModal();
       }
       else
       {
           CDialogEx::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 CMFCApplicationThresdDlg::OnPaint()
   {
       if (IsIconic())
       {
           CPaintDC dc(this); // device context for painting
   
           SendMessage(WM_ICONERASEBKGND, reinterpret_cast<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
       {
           CDialogEx::OnPaint();
       }
   }
   
   // The system calls this function to obtain the cursor to display while the user drags
   //  the minimized window.
   HCURSOR CMFCApplicationThresdDlg::OnQueryDragIcon()
   {
       return static_cast<HCURSOR>(m_hIcon);
   }
   
   
   
   void CMFCApplicationThresdDlg::Btn_Clicked_Start()
   {
       // TODO: Add your control notification handler code here
       ThreadParam *pRecvParam = new ThreadParam;
       pRecvParam->ThreadVal = 0;
       pRecvParam->ThreadID = m_hWnd;
       //create thread
       HANDLE hThread = CreateThread(NULL, 0, ThreadProc, (LPVOID)pRecvParam, 0, NULL);
   }
   DWORD CMFCApplicationThresdDlg::ThreadProc(LPVOID lpParameter)
   {
       WORD value = ((ThreadParam*)lpParameter)->ThreadVal;
       HWND hwnd = ((ThreadParam*)lpParameter)->ThreadID;
       while (1)
       {
           value++;
           ::PostMessage(hwnd, WM_RESPONSE, 0, (LPARAM)value);
           Sleep(1000);
       }
       return 0;
   }
   LRESULT CMFCApplicationThresdDlg::winMessageFun(WPARAM wParam, LPARAM lParam)
   {
       UNREFERENCED_PARAMETER(wParam);
       UNREFERENCED_PARAMETER(lParam);
       WORD value = lParam;
       CString str;
       str.Format(_T("%d
   "), value);
       m_edit1 += str;
       UpdateData(FALSE);
       return 0;
   }

   // MFCApplicationThresdDlg.h : header file
   //
   
   #pragma once
   
   
   // CMFCApplicationThresdDlg dialog
   #define WM_RESPONSE    WM_USER+1
   struct ThreadParam
   {
       HWND ThreadID;
       WORD ThreadVal;
   };
   class CMFCApplicationThresdDlg : public CDialogEx
   {
   // Construction
   public:
       CMFCApplicationThresdDlg(CWnd* pParent = NULL);    // standard constructor
   
   // Dialog Data
       enum { IDD = IDD_MFCAPPLICATIONTHRESD_DIALOG };
   private:
       static DWORD WINAPI ThreadProc(LPVOID lpParameter);
   
       protected:
       virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
   
   
   // Implementation
   protected:
       HICON m_hIcon;
   
       // Generated message map functions
       virtual BOOL OnInitDialog();
       afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
       afx_msg void OnPaint();
       afx_msg HCURSOR OnQueryDragIcon();
       afx_msg LRESULT winMessageFun(WPARAM wParam, LPARAM lParam);
       DECLARE_MESSAGE_MAP()
   public:
       CString m_edit1;
       afx_msg void Btn_Clicked_Start();
   };

谢谢！

End.