CStdioFile对文件的某一行进行修改

来源：互联网发布：二叉树算法编辑：程序博客网时间：2024/05/16 11:35

举个例子，有一文本文件test.txt如下：
192.168.1.1:1,60.000,60.000
192.168.1.1:2,60.000,60.000
192.168.1.1:3,60.000,60.000
192.168.1.1:5,60.000,60.000
192.168.1.1:21,60.000,60.000
192.168.1.1:34,60.000,60.000
192.168.1.1:35,60.000,60.000
192.168.1.1:66,60.000,60.000
192.168.1.1:123,60.000,60.000
192.168.1.1:234,60.000,60.000

找到192.168.1.1:21这行，并将其后面的值改为40.000,40.000，即这行值变为“192.168.1.1:21,40.000,40.000”

CStdioFile file;
    file.Open("a.txt",CFile::modeReadWrite);
    CString str;
    while(true){
        file.ReadString(str);
        if(str.Left(str.Find(",",0))==CString("192.168.1.1:21")){
            file.Seek(-2-str.GetLength(),CFile::current);

//file.Seek(0,CFile::current);
file.Write("192.168.1.1:21,40.000,40.000/n",strlen("192.168.1.1:21,40.000,40.000"));

                        //file.Write("192.168.1.1:21,40.000,40.000",strlen("192.168.1.1:21,40.000,40.000"));
            break;
        }
    }
    file.Close();