多種方法讀寫檔案

C方式：

寫：

FILE *pFile = fopen("1.txt", "w");

fwrite("http://www.pcslonline.com", 1, strlen("http://www.pcslonline.com"), pFile);

fclose(pFile);

讀：

FILE *pFileRead = fopen("1.txt", "r");

char *pBuf;

fseek(pFileRead, 0, SEEK_END);   //把檔案指針移動到檔案結尾

int length = ftell(pFileRead);//取檔案長度

pBuf = new char[length + 1];//多取一位，最後一位放0；

rewind(pFileRead);//重新把檔案指針移動到開頭

fread(pBuf, 1, length, pFileRead);

pBuf[length] = 0;

MessageBox(pBuf);//MessageBox函數遇到 0 就停止。

fclose(pFileRead);

定長讀檔案：

 1.//char ch[100] = {0};//全部初始化為0； 

 2.char ch[100];

 memset(ch, 0, 100);//全部初始化為0；

 fread(ch, 1, 100, pFileRead);

 MessageBox(ch);//MessageBox函數遇到 0 就停止。

 C++方式： #include <fstream.h>

ofstream ofs(_T("2.txt"));

ofs.write(_T("minzhenfei"), strlen(_T("minzhenfei")));

ofs.close();

ifstream ifs("2.txt");

char ch[100];

memset(ch, 0, 100);

ifs.read(ch, 100);

ifs.close();

MessageBox(ch);

SDK方式：

HANDLE hFile = CreateFile("3.txt", GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

DWORD dwFileWrite;

//CHAR ch[] = "minzhenfei shi da tiancai";

LPSTR ch = "Hello world!";

WriteFile(hFile, ch, lstrlen(ch), &dwFileWrite, NULL);

CloseHandle(hFile);

HANDLE hFileRead = CreateFile("3.txt", GENERIC_READ, 0, NULL, OPEN_EXISTING , FILE_ATTRIBUTE_NORMAL, NULL);

CHAR ch[100];

DWORD dwReads;

ReadFile(hFileRead, ch, 100, &dwReads, NULL);

CloseHandle(hFileRead);

ch[dwReads] = 0;

MFC方法：

CFile fileWrite("4.txt", CFile::modeCreate | CFile::modeWrite );

fileWrite.Write("Hello MFC!", lstrlen("Hello MFC!"));

fileWrite.Close();

CFile fileRead("4.txt", CFile::modeRead);

CHAR *pBuf;

DWORD strlen;

strlen = fileRead.GetLength();

pBuf = new CHAR[strlen + 1];

fileRead.Read(pBuf, strlen);

pBuf[strlen] = 0;