MFC 读写文件

写入文件：

CFile file("abc.txt", CFile::modeWrite|CFile::modeCreate); //打开abc.txt文件
CString str = "abcedkwfjwfj";
file.Write(str, str.GetLength()); //写入文件
file.Close();

读取文件：

CFile file("abc.txt", CFile::modeRead);
DWORD dwFileLen;
dwFileLen = file.GetLength();
char* pBuf;
pBuf = new char[dwFileLen+1];
pBuf[dwFileLen] = 0;
file.Read(pBuf,dwFileLen);
file.Close();
CString csBuf;
csBuf.Format("%s", pBuf); //csBuf字符串即为abc.txt中的字符串
MessageBox(csBuf, "", MB_OK);

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举例：

1.先用vc6.0创建个MFC的对话框程序 ReadFile工程，界面如下图：



2.在对话框上右键，建立【类向导】(classwizard)，在【成员变量】(Member Variables)中为控件添加关联变量。如下图：



3.在双击【保存】按钮，为点击事件添加代码：

void CReadFileDlg::OnButton1()
{
// TODO: Add your control notification handler code here
SYSTEMTIME stTime;
GetLocalTime(&stTime); //获取系统时间
CString date;
date.Format("%4d年%2d月%2d日.txt", stTime.wYear, stTime.wMonth, stTime.wDay); //以系统时间作为文件名
CFile file(date, CFile::modeWrite|CFile::modeCreate);
CString huanhang = "#";
CString xing = "*";
UpdateData(TRUE);
file.Write(m_income, m_income.GetLength());
file.Write(huanhang, huanhang.GetLength());
file.Write(m_pay, m_pay.GetLength());
file.Write(xing, xing.GetLength());
file.Write(m_cash, m_cash.GetLength());
UpdateData(FALSE);
file.Close();
}

4.双击【查看】按钮，为点击事件添加代码：

void CReadFileDlg::OnButton2()
{
// TODO: Add your control notification handler code here
SYSTEMTIME stTime;
GetLocalTime(&stTime);
CString date;
date.Format("%4d年%2d月%2d日.txt", stTime.wYear, stTime.wMonth, stTime.wDay);
CFile file(date, CFile::modeRead);
DWORD dwFileLen;
dwFileLen = file.GetLength();
char* pBuf;
pBuf = new char[dwFileLen+1];
pBuf[dwFileLen] = 0;
file.Read(pBuf,dwFileLen);
file.Close();
CString csBuf, cstemp;
csBuf.Format("%s", pBuf);
int flag1 = csBuf.Find('#', 0);
int flag2 = csBuf.Find('*', 0);
UpdateData(TRUE);
m_income = csBuf.Left(flag1);
m_pay = csBuf.Mid(flag1 + 1, flag2-1 - flag1);
m_cash = csBuf.Right(csBuf.GetLength()-1 - flag2);
UpdateData(FALSE);
delete []pBuf;
}