C++杂记 05/08/2011 开始一个完整的WTL例子

本文详细记录了使用C++和Windows Template Library (WTL) 创建一个简单Win32项目的步骤，从创建empty win32 project开始，到遇到并解决编译错误，最终成功运行一个显示窗口但未填充内容的应用。过程中提到了类定义问题、消息映射和视图的添加，展示了如何在WTL中处理消息。

1. 生成empty win32 project

2. 加入My1stWTL70Win.cpp

int WINAPI _tWinMain(HINSTANCE hInstance, HINSTANCE /*hPrevInstance*/, LPTSTR lpstrCmdLine, int nCmdShow)
{...}

int Run(LPTSTR /*lpstrCmdLine*/ = NULL, int nCmdShow = SW_SHOWDEFAULT)
{...}

3. 添加MyMainWnd Class

class MyMainWnd : public CFrameWindowImpl<MyMainWnd>
{
public:
MyMainWnd();
virtual ~MyMainWnd();

};

Error:

MyMainWnd.cpp
d:/study/wtl/hellowtl70/my1stwtl70win/mymainwnd.h(12) : error C2504: 'CFrameWindowImpl' : base class undefined
d:/study/wtl/hellowtl70/my1stwtl70win/mymainwnd.h(12) : error C2143: syntax error : missing ',' before '<'
d:/study/wtl/hellowtl70/my1stwtl70win/mymainwnd.h(12) : error C2059: syntax error : '<'
Error executing cl.exe.

4. 去掉MyMainWnd.cpp文件，OK ？

最后的结果，一个空的windows。相关代码如下：

#include "stdafx.h"

#include <atlframe.h>
#include <atlctrls.h>
#include <atldlgs.h>
#include <atlctrlw.h>

#include "MyMainWnd.h"

CAppModule _Module;

int Run(LPTSTR /*lpstrCmdLine*/ = NULL, int nCmdShow = SW_SHOWDEFAULT)
{
    CMessageLoop theLoop;
    _Module.AddMessageLoop(&theLoop);

    //CMainFrame wndMain;
    MyMainWnd wndMain;

    if(wndMain.CreateEx() == NULL)
    {
        ATLTRACE(_T("Main window creation failed!/n"));
        return 0;
    }

    wndMain.ShowWindow(nCmdShow);

    int nRet = theLoop.Run();

    _Module.RemoveMessageLoop();

    return nRet;

}

int WINAPI _tWinMain(HINSTANCE hInstance, HINSTANCE /*hPrevInstance*/, LPTSTR lpstrCmdLine, int nCmdShow)
{
    HRESULT hRes = ::CoInitialize(NULL);
    // If you are running on NT 4.0 or higher you can use the following call instead to
    // make the EXE free threaded. This means that calls come in on a random RPC thread.
    //    HRESULT hRes = ::CoInitializeEx(NULL, COINIT_MULTITHREADED);
    ATLASSERT(SUCCEEDED(hRes));

    // this resolves ATL window thunking problem when Microsoft Layer for Unicode (MSLU) is used
    ::DefWindowProc(NULL, 0, 0, 0L);

    AtlInitCommonControls(ICC_COOL_CLASSES | ICC_BAR_CLASSES);    // add flags to support other controls

    hRes = _Module.Init(NULL, hInstance);
    ATLASSERT(SUCCEEDED(hRes));

    int nRet = Run(lpstrCmdLine, nCmdShow);

    _Module.Term();
    ::CoUninitialize();

    return nRet;
}

注：此程序在关闭窗口后，进程并没有消失，奇怪！！！

5. 增加一个view: MyView

Error:

Compiling...
My1stWTL70Win.cpp
d:/study/wtl/hellowtl70/my1stwtl70win/mymainwnd.h(19) : error C2146: syntax error : missing ';' before identifier 'myView'
d:/study/wtl/hellowtl70/my1stwtl70win/mymainwnd.h(19) : error C2501: 'MyView' : missing storage-class or type specifiers
d:/study/wtl/hellowtl70/my1stwtl70win/mymainwnd.h(19) : error C2501: 'myView' : missing storage-class or type specifiers
Error executing cl.exe.

A: 在MyMainWnd.h中加入头文件：

#include "MyView.h"

Compile OK ! ( WHY wizard-generated files have no such issue ?! 头文件被引入的顺序有关系？)

**** 目前状态 ****

窗口显示出来了，但view里面没有东东。

这里有一篇文章讲WTL消息处理的：http://blog.youkuaiyun.com/fengrx/archive/2009/05/09/4163169.aspx

6. 让View显示东东，终于搞定！

主要修改：在Message map中增加 CHAIN_MSG_MAP(CFrameWindowImpl<MyMainWnd>)

MyMainWnd.h的完整代码如下：

#include "MyView.h"
class MyMainWnd : public CFrameWindowImpl<MyMainWnd>//, public CUpdateUI<MyMainWnd>
{
public:
    DECLARE_FRAME_WND_CLASS(NULL, NULL)
    MyView myView;
    MyMainWnd(){}
    virtual ~MyMainWnd(){}
    BEGIN_MSG_MAP(MyMainWnd)
        MESSAGE_HANDLER(WM_CREATE, OnCreate)
        //CHAIN_MSG_MAP(CUpdateUI<MyMainWnd>)
        CHAIN_MSG_MAP(CFrameWindowImpl<MyMainWnd>)
    END_MSG_MAP()

public:
    LRESULT OnCreate(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
    {
        m_hWndClient = myView.Create(m_hWnd, rcDefault, NULL, WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, WS_EX_CLIENTEDGE);
        CMessageLoop* pLoop = _Module.GetMessageLoop();
        ATLASSERT(pLoop != NULL);
        return 0;
    }
};