fileio.h

Windows下的简易小画板

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

static OPENFILENAME ofn ;

void PopFileInitialize (HWND hwnd)
{
	static TCHAR szFilter[] = TEXT ("Text Files (*.GWT)\0*.gwt\0")  \
		TEXT ("ASCII Files (*.ASC)\0*.asc\0") \
		TEXT ("All Files (*.*)\0*.*\0\0") ;
	
	ofn.lStructSize       = sizeof (OPENFILENAME) ;
	ofn.hwndOwner         = hwnd ;
	ofn.hInstance         = NULL ;
	ofn.lpstrFilter       = szFilter ;
	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       = TEXT ("txt") ;
	ofn.lCustData         = 0L ;
	ofn.lpfnHook          = NULL ;
	ofn.lpTemplateName    = NULL ;
}

BOOL PopFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
{
	ofn.hwndOwner         = hwnd ;
	ofn.lpstrFile         = pstrFileName ;
	ofn.lpstrFileTitle    = pstrTitleName ;
	ofn.Flags             = OFN_HIDEREADONLY | OFN_CREATEPROMPT ;
	
	return GetOpenFileName (&ofn) ;
}

BOOL PopFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
{
	ofn.hwndOwner         = hwnd ;
	ofn.lpstrFile         = pstrFileName ;
	ofn.lpstrFileTitle    = pstrTitleName ;
	ofn.Flags             = OFN_OVERWRITEPROMPT ;
	
	return GetSaveFileName (&ofn) ;
}

BOOL PopFileRead (HWND hwndEdit, PTSTR pstrFileName)
{
	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 = malloc (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 = malloc (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 = malloc (2 * iFileLength + 2) ;
		
		// If the edit control is Unicode, convert ASCII text.
		
#ifdef UNICODE
		MultiByteToWideChar (CP_ACP, 0, pText, -1, (PTSTR) pConv, 
			iFileLength + 1) ;
		
		// If not, just copy buffer
#else
		lstrcpy ((PTSTR) pConv, (PTSTR) pText) ;
#endif
	}
	
	SetWindowText (hwndEdit, (PTSTR) pConv) ;
	free (pBuffer) ;
	free (pConv) ;
	
	return TRUE ;
}

BOOL PopFileWrite (HWND hwndEdit, PTSTR pstrFileName)
{
	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 = (PTSTR) malloc ((iLength + 1) * sizeof (TCHAR)) ;
	
	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) ;
		free (pstrBuffer) ;
		return FALSE ;
	}
	
	CloseHandle (hFile) ;
	free (pstrBuffer) ;
	
	return TRUE ;
}