分享一个PopFile的库，原来windows程序设计里边有很多很好的东西，一直都在错过！

解释一个这个class的用途

构造函数说明：

主要用在弹出一个文件对话框，第一次使用的时候需要实例化，
有两个参数，第一个是父窗口句柄(即PopFile dlg属于那个的管辖)
第二个参数是要写入的窗口句柄(当使用Write的时候需要用到)


当然你也可能只需要从对话框中获取文件名，那样你只需要在实例化中只传入第二个参数


PopFileWrite(PTSTR pstrFileName)：
当你执行保存操作之后，把当前构造函数第二个参数(写入的窗口句柄)中的内容，写到相应的pstrFileName中


同理PopFileRead是PopFileWrite的逆过程

下面提供一个使用该class(库)的例子：

对应的下载地址：

http://download.csdn.net/detail/zengraoli/5311361

// Win32Project1.cpp : 定义应用程序的入口点。
//

#include "stdafx.h"
#include "Win32Project1.h"
#include "PopFile.h"

#define EDITID			1
#define MAX_LOADSTRING	100
#define UNTITLED		TEXT ("(untitled)")

#pragma comment(lib, "PopFile.lib")

PopFile *pop_file;

// 全局变量:
HINSTANCE hInst;								// 当前实例

// 此代码模块中包含的函数的前向声明:
ATOM				MyRegisterClass(HINSTANCE hInstance);
BOOL				InitInstance(HINSTANCE, int);
LRESULT CALLBACK	WndProc(HWND, UINT, WPARAM, LPARAM);
void  ShowMessage(HWND  hwnd, TCHAR *szMessage, TCHAR *szTitleName);
short AskAboutSave(HWND hwnd, TCHAR *szTitleName);

int APIENTRY _tWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPTSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
	UNREFERENCED_PARAMETER(hPrevInstance);
	UNREFERENCED_PARAMETER(lpCmdLine);

 	// TODO: 在此放置代码。
	MSG msg = {0};

	// 初始化全局字符串
	MyRegisterClass(hInstance);

	// 执行应用程序初始化:
	if (!InitInstance (hInstance, nCmdShow))
	{
		return FALSE;
	}

	// 主消息循环:
	while (msg.message != WM_QUIT)
	{
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
		else
		{
			Sleep(100);
		}
	}

	return (int) msg.wParam;
}



//
//  函数: MyRegisterClass()
//
//  目的: 注册窗口类。
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
	WNDCLASSEX wcex;

	wcex.cbSize = sizeof(WNDCLASSEX);

	wcex.style			= CS_HREDRAW | CS_VREDRAW;
	wcex.lpfnWndProc	= WndProc;
	wcex.cbClsExtra		= 0;
	wcex.cbWndExtra		= 0;
	wcex.hInstance		= hInstance;
	wcex.hIcon			= LoadIcon(hInstance, MAKEINTRESOURCE(IDI_WIN32PROJECT1));
	wcex.hCursor		= LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground	= (HBRUSH)(COLOR_WINDOW+1);
	wcex.lpszMenuName	= MAKEINTRESOURCE(IDC_WIN32PROJECT1);
	wcex.lpszClassName	= L"test";
	wcex.hIconSm		= LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

	return RegisterClassEx(&wcex);
}

//
//   函数: InitInstance(HINSTANCE, int)
//
//   目的: 保存实例句柄并创建主窗口
//
//   注释:
//
//        在此函数中，我们在全局变量中保存实例句柄并
//        创建和显示主程序窗口。
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   HWND hWnd;

   hInst = hInstance; // 将实例句柄存储在全局变量中

   hWnd = CreateWindow(L"test", L"test", WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

   if (!hWnd)
   {
      return FALSE;
   }

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

//
//  函数: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  目的: 处理主窗口的消息。
//
//  WM_COMMAND	- 处理应用程序菜单
//  WM_PAINT	- 绘制主窗口
//  WM_DESTROY	- 发送退出消息并返回
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static  BOOL      bNeedSave = FALSE ;
	static  HINSTANCE hInst ;
	static  HWND		 hWndEdit;
	int		wmId, wmEvent;
	static  TCHAR     szFileName[MAX_PATH], szTitleName[MAX_PATH] ;
	switch (message)
	{
	case WM_CREATE:
		hInst = ((LPCREATESTRUCT)lParam)->hInstance;
		hWndEdit = CreateWindow (TEXT ("edit"), NULL,
			WS_CHILD | WS_VISIBLE | WS_HSCROLL | WS_VSCROLL |
			WS_BORDER | ES_LEFT | ES_MULTILINE |
			ES_NOHIDESEL | ES_AUTOHSCROLL | ES_AUTOVSCROLL,
			0, 0, 0, 0,
			hWnd, (HMENU) EDITID, hInst, NULL) ;

		SendMessage(hWndEdit, EM_LIMITTEXT, 32000, 0L) ;

		// create and Initialize pop file
		pop_file = new PopFile(hWnd, hWndEdit);

		break;
	case WM_SETFOCUS:
		SetFocus(hWndEdit) ;
		return 0 ;
	case WM_SIZE: 
		MoveWindow(hWndEdit, 0, 0, LOWORD (lParam), HIWORD (lParam), TRUE);
		return 0 ;
	case WM_COMMAND:
		wmId    = LOWORD(wParam);
		wmEvent = HIWORD(wParam);
		// 分析菜单选择:
		switch (wmId)
		{
		case ID_NEW:
			if (bNeedSave && IDCANCEL == AskAboutSave (hWnd, szTitleName))
				return 0 ;

			SetWindowText(hWndEdit, TEXT ("\0")) ;
			szFileName[0]  = '\0';
			szTitleName[0] = '\0';
			bNeedSave = FALSE ;
			return 0 ;

		case ID_OPEN:
			if (bNeedSave && IDCANCEL == AskAboutSave(hWnd, szTitleName))
				return 0 ;
			// 这里做一下初始化的判断
			if (pop_file->PopFileOpenDlg(szFileName, szTitleName))
			{
				if (!pop_file->PopFileRead(szFileName))
				{
					ShowMessage(hWnd, TEXT ("Could not read file %s!"), szTitleName) ;
					szFileName[0]  = '\0' ;
					szTitleName[0] = '\0' ;
				}
			}
			bNeedSave = FALSE ;
			return 0 ;

		case ID_SAVE:
			if (szFileName[0])
			{
				if (pop_file->PopFileWrite(szFileName))
				{
					bNeedSave = FALSE ;
					return 1 ;
				}
				else
				{
					ShowMessage(hWnd, TEXT ("Could not write file %s"), szTitleName) ;
					return 0 ;
				}
			}
			// fall through
		case ID_SAVEAS:
			if (pop_file->PopFileSaveDlg(szFileName, szTitleName))
			{
				if (pop_file->PopFileWrite(szFileName))
				{
					bNeedSave = FALSE ;
					return 1 ;
				}
				else
				{
					ShowMessage(hWnd, TEXT ("Could not write file %s"),
						szTitleName) ;
					return 0 ;
				}
			}
			return 0 ;

		default:
			return DefWindowProc(hWnd, message, wParam, lParam);
		}
		break;
	case WM_KEYDOWN:
		if (wParam == VK_ESCAPE)
		{
			SendMessage(hWnd, WM_CLOSE, 0, 0);
		}
		break;
	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hWnd, message, wParam, lParam);
	}
	return 0;
}

short AskAboutSave(HWND hwnd, TCHAR * szTitleName)
{
	TCHAR szBuffer[64 + MAX_PATH] ;
	int   iReturn ;

	wsprintf (szBuffer, TEXT ("Save current changes in %s?"),
		szTitleName[0] ? szTitleName : UNTITLED) ;

	iReturn = MessageBox (hwnd, szBuffer, L"test",
		MB_YESNOCANCEL | MB_ICONQUESTION) ;

	if (iReturn == IDYES)
		if (!SendMessage (hwnd, WM_COMMAND, ID_SAVE, 0))
			iReturn = IDCANCEL ;

	return iReturn ;
}

void ShowMessage(HWND hwnd, TCHAR * szMessage, TCHAR * szTitleName)
{
	TCHAR szBuffer[64 + MAX_PATH] ;

	wsprintf(szBuffer, szMessage, szTitleName[0] ? szTitleName : UNTITLED) ;

	MessageBox(hwnd, szBuffer, L"test", MB_OK | MB_ICONEXCLAMATION) ;
}

库的源代码：

下载地址：

http://download.csdn.net/detail/zengraoli/5311397

.h：

#include <windows.h>
#include <commdlg.h>

#ifdef  MYLIBAPI
#else
#define MYLIBAPI __declspec(dllimport)
#endif

#define RELEASE(p) if (p)	\
{							\
	delete p;				\
	p = NULL;				\
}

#define FILTER	TEXT ("Text Files (*.TXT)\0*.txt\0")  \
	TEXT ("All Files (*.*)\0*.*\0\0")

// default file extend
#define DEFEXT_FILE_POSTFIX TEXT ("txt")

class MYLIBAPI PopFile
{
public:
	PopFile(HWND hWnd, HWND hWndEdit = NULL);
	BOOL PopFileOpenDlg(PTSTR pstrFileName, PTSTR pstrTitleName);	
	BOOL PopFileSaveDlg(PTSTR pstrFileName, PTSTR pstrTitleName);
	BOOL PopFileRead(PTSTR pstrFileName);
	BOOL PopFileWrite(PTSTR petrFileName);

private:
	void PopFileInitialize(TCHAR Filter[] = FILTER);

private:
	OPENFILENAME ofn_;
	HWND hWnd_;
	HWND hWndEdit_;
};

.cpp：

// PopFile.cpp : 定义 DLL 应用程序的导出函数。
//

#define MYLIBAPI __declspec(dllexport) 

#include "PopFile.h"

/// <summary>
/// create a new instance of the class, and Initializes.
/// </summary>
/// <param name="hWnd">The Pop parent hwnd.</param>
/// <param name="hWndEdit">The read or write purpose hwnd.</param>
PopFile::PopFile(HWND hWnd, HWND hWndEdit)
{
	hWnd_	  = hWnd;
	hWndEdit_ = hWndEdit;
	PopFileInitialize();
}

void PopFile::PopFileInitialize(TCHAR Filter[])
{
	ofn_.lStructSize       = sizeof (OPENFILENAME) ;
	ofn_.hwndOwner         = hWnd_ ;
	ofn_.hInstance         = NULL ;
	ofn_.lpstrFilter       = Filter ;
	ofn_.lpstrCustomFilter = NULL ;
	ofn_.nMaxCustFilter    = 0 ;
	ofn_.nFilterIndex      = 0 ;
	ofn_.lpstrFile         = NULL ;          // Set in Open and Close functions
	ofn_.nMaxFile          = MAX_PATH ;
	ofn_.lpstrFileTitle    = NULL ;          // Set in Open and Close functions
	ofn_.nMaxFileTitle     = MAX_PATH ;
	ofn_.lpstrInitialDir   = NULL ;
	ofn_.lpstrTitle        = NULL ;
	ofn_.Flags             = 0 ;             // Set in Open and Close functions
	ofn_.nFileOffset       = 0 ;
	ofn_.nFileExtension    = 0 ;
	ofn_.lpstrDefExt       = DEFEXT_FILE_POSTFIX;
	ofn_.lCustData         = 0L ;
	ofn_.lpfnHook          = NULL ;
	ofn_.lpTemplateName    = NULL ;
}

/// <summary>
/// Pops the file open DLG.
/// </summary>
/// <param name="pstrFileName">指向包含初始化文件名编辑控件使用的文件名的缓冲.</param>
/// <param name="pstrTitleName">指向接收选择的文件的文件名和扩展名的缓冲.</param>
/// <returns>BOOL.</returns>
BOOL PopFile::PopFileOpenDlg(PTSTR pstrFileName, PTSTR pstrTitleName)
{
	ofn_.hwndOwner         = hWnd_ ;
	ofn_.lpstrFile         = pstrFileName ;
	ofn_.lpstrFileTitle    = pstrTitleName ;
	ofn_.Flags             = OFN_HIDEREADONLY | OFN_CREATEPROMPT ;

	return GetOpenFileName (&ofn_) ;
}

BOOL PopFile::PopFileSaveDlg(PTSTR pstrFileName, PTSTR pstrTitleName)
{
	ofn_.hwndOwner         = hWnd_ ;
	ofn_.lpstrFile         = pstrFileName ;
	ofn_.lpstrFileTitle    = pstrTitleName ;
	ofn_.Flags             = OFN_OVERWRITEPROMPT ;

	return GetSaveFileName (&ofn_) ;
}

/// <summary>
/// Pops the file read.
/// </summary>
/// <param name="pstrFileName">file name and path to read.</param>
/// <returns>BOOL.</returns>
BOOL PopFile::PopFileRead(PTSTR pstrFileName)
{
	if (NULL != hWndEdit_)
	{
		BYTE   bySwap ;
		DWORD  dwBytesRead ;
		HANDLE hFile ;
		int    i, iFileLength, iUniTest ;
		PBYTE  pBuffer, pText, pConv ;

		// Open the file.
		if (INVALID_HANDLE_VALUE == 
			(hFile = CreateFile(pstrFileName, GENERIC_READ, FILE_SHARE_READ,
			NULL, OPEN_EXISTING, 0, NULL)))
			return FALSE ;

		// Get file size in bytes and allocate memory for read.
		// Add an extra two bytes for zero termination.

		iFileLength = GetFileSize (hFile, NULL) ; 

		pBuffer = new BYTE[iFileLength + 2];

		// Read file and put terminating zeros at end.

		ReadFile(hFile, pBuffer, iFileLength, &dwBytesRead, NULL) ;
		CloseHandle(hFile) ;
		pBuffer[iFileLength] = '\0' ;
		pBuffer[iFileLength + 1] = '\0' ;

		// Test to see if the text is Unicode
		iUniTest = IS_TEXT_UNICODE_SIGNATURE | IS_TEXT_UNICODE_REVERSE_SIGNATURE ;

		if (IsTextUnicode(pBuffer, iFileLength, &iUniTest))
		{
			pText = pBuffer + 2 ;
			iFileLength -= 2 ;

			if (iUniTest & IS_TEXT_UNICODE_REVERSE_SIGNATURE)
			{
				for (i = 0 ; i < iFileLength / 2 ; i++)
				{
					bySwap = ((BYTE *) pText) [2 * i] ;
					((BYTE *) pText) [2 * i] = ((BYTE *) pText) [2 * i + 1] ;
					((BYTE *) pText) [2 * i + 1] = bySwap ;
				}
			}

			// Allocate memory for possibly converted string
			pConv = new BYTE[iFileLength + 2];

			// If the edit control is not Unicode, convert Unicode text to 
			// non-Unicode (ie, in general, wide character).

#ifndef UNICODE
			WideCharToMultiByte(CP_ACP, 0, (PWSTR) pText, -1, pConv, 
				iFileLength + 2, NULL, NULL) ;

			// If the edit control is Unicode, just copy the string
#else
			lstrcpy((PTSTR) pConv, (PTSTR) pText) ;
#endif

		}
		else      // the file is not Unicode
		{
			pText = pBuffer ;

			// Allocate memory for possibly converted string.
			pConv = new BYTE[2 * iFileLength + 2];

			// If the edit control is Unicode, convert ASCII text.

#ifdef UNICODE
			MultiByteToWideChar(CP_ACP, 0, (LPCCH)pText, -1, (PTSTR) pConv, 
				iFileLength + 1) ;

			// If not, just copy buffer
#else
			lstrcpy((PTSTR) pConv, (PTSTR) pText) ;
#endif
		}

		SetWindowText(hWndEdit_, (PTSTR) pConv) ;
		RELEASE(pBuffer);
		RELEASE(pConv);
	}

	return TRUE ;
}

/// <summary>
/// Pops the file read.
/// </summary>
/// <param name="pstrFileName">file name and path to write.</param>
/// <returns>BOOL.</returns>
BOOL PopFile::PopFileWrite(PTSTR pstrFileName)
{
	if (NULL != hWndEdit_)
	{
		DWORD  dwBytesWritten ;
		HANDLE hFile ;
		int    iLength ;
		PTSTR  pstrBuffer ;
		WORD   wByteOrderMark = 0xFEFF ;

		// Open the file, creating it if necessary

		if (INVALID_HANDLE_VALUE == 
			(hFile = CreateFile(pstrFileName, GENERIC_WRITE, 0, 
			NULL, CREATE_ALWAYS, 0, NULL)))
			return FALSE ;

		// Get the number of characters in the edit control and allocate
		// memory for them.

		iLength = GetWindowTextLength(hWndEdit_) ;
		pstrBuffer = new TCHAR[iLength + 1];

		if (!pstrBuffer)
		{
			CloseHandle(hFile) ;
			return FALSE ;
		}

		// If the edit control will return Unicode text, write the
		// byte order mark to the file.

#ifdef UNICODE
		WriteFile(hFile, &wByteOrderMark, 2, &dwBytesWritten, NULL) ;
#endif

		// Get the edit buffer and write that out to the file.

		GetWindowText(hWndEdit_, pstrBuffer, iLength + 1) ;
		WriteFile(hFile, pstrBuffer, iLength * sizeof (TCHAR), 
			&dwBytesWritten, NULL) ;

		if ((iLength * sizeof (TCHAR)) != (int) dwBytesWritten)
		{
			CloseHandle(hFile) ;
			RELEASE(pstrBuffer);
			return FALSE ;
		}

		CloseHandle(hFile) ;
		RELEASE(pstrBuffer);
	}

	return TRUE ;
}