在线等:怎样将一个浮点型的数组存储为*.dat或者*.txt?

[wfth]

请哪位好心的大哥帮帮忙啊!

[wfth]

没人回答呀?谁帮我一下嘛

[handsomerun]

没看懂，

你的意思是把数据存到一个文件里面吗？？

如果是话，用fstream进行写文件吧，

[wfth]

是的,我就是这个意思,我几乎没有接触过VC,现在需要用一下完成一些简单的操作.可就是搞不懂,麻烦你说详细一点好吗?

[sant]

按BYTE的内存形式存。

[handsomerun]

你建一个win32console程序

然后有如下代码就可以写进去了

#include "stdafx.h"
#include <fstream.h>


int main(int argc, char* argv[])
{
fstream ff("a.text",ios::out);
double a[10] = {1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2.0};
ff<<"a[0]=%f"<<a[0]<<endl;
ff<<"a[2]=%f"<<a[2]<<endl;
ff<<"a[4]=%f"<<a[4]<<endl;
ff<<"a[6]=%f"<<a[6]<<endl;

return 0;
}


a.text是你的文件名，没有设置路径的话，保存在当前目录下
构造fstream对象的时候
fstream( const char* szName, int nMode, int nProt = filebuf::openprot );

szName

The name of the file to be opened during construction.

nMode

An integer that contains mode bits defined as ios enumerators that can be combined with the bitwise OR ( | ) operator. The nMode parameter must have one of the following values:

ios::app The function performs a seek to the end of file. When new bytes are written to the file, they are always appended to the end, even if the position is moved with the ostream::seekp function.


ios::ate The function performs a seek to the end of file. When the first new byte is written to the file, it is appended to the end, but when subsequent bytes are written, they are written to the current position.


ios::in The file is opened for input. The original file (if it exists) will not be truncated.


ios::out The file is opened for output.


ios::trunc If the file already exists, its contents are discarded. This mode is implied if ios::out is specified, and ios::ate, ios::app, and ios:in are not specified.


ios::nocreate If the file does not already exist, the function fails.


ios::noreplace If the file already exists, the function fails.


ios::binary Opens the file in binary mode (the default is text mode).
Note that there is no ios::in or ios::out default mode for fstream objects. You must specify both modes if your fstream object must both read and write files.


只要设置这两个参数就可以了

[wfth]

非常感谢!

[wfth]

怎么给分啊?

[handsomerun]

如果你是ｍｆｃ的程序，那么可以用ｃｆｉｌｅ的类
然后建一个ｃｆｉｌｅ对象，用write函数把数组的内容写进去

HANDLE hFile = CreateFile(_T("C:\\FOO.DAT"),
GENERIC_WRITE, FILE_SHARE_READ,
NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

if (hFile == INVALID_HANDLE_VALUE)
AfxMessageBox(_T("Couldn't create the file!"));
else
{
// Attach a CFile object to the handle we have.
CFile myFile(hFile);

static const char sz[] = "Hockey is best!";

// write string, without null-terminator
myFile.Write(sz, lstrlen(sz));

// We can call Close() explicitly, but the destructor would have
// also closed the file for us. Note that there's no need to
// call the CloseHandle() on the handle returned by the API because
// MFC will close it for us.
myFile.Close();
}

这是ｍｓｄｎ上使用ｃｆｉｌｅ的例子，
你可以参考一下，呵呵

[handsomerun]

点右上角的管理就可以了
晕了

[wfth]

存一个字符串的时候,我倒是会一点,可是如果是存浮点型的数据的时候,存了之后就变成乱码了,不知道是怎么回事.

[handsomerun]

你怎么存的呢，怎么会存成乱吗了

[wfth]

我是这样做的:
CFile file("e:\\test.txt",CFile::modeCreate|CFile::modeReadWrite);
double a[10] = {1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2.0};
file.Write(a,10)
file.close();
就是乱码,不知道什么原因

[handsomerun]

那当然是乱吗啦
你这个ａ是一个ｄｏｕｂｌｅ的数组
那么file.Write(a,10)
的话，你就把ａ的地址输出来了

Write的第一个参数得要是一个字符篡才行呢，呵呵

你把你的这些ｆｌｏａｔ拼成字符窜才能通过Write写出来
这个和ff<<a[0]<<endl是不一样的

CFile file("test.txt",CFile::modeCreate|CFile::modeReadWrite);
double a[10] = {1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2.0};
CString ss;
ss.Format("%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,%f",a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9]);
//file.Write(a,10);
file.Write(ss,ss.GetLength());
file.Close();

这样就ｏｋ了，当然，这个字符窜的格式怎么样，你还可以自己拼凑

[handsomerun]

有ｍｓｄｎ的话，可以去看看ｍｓｄｎ，嗯嗯，慢慢研究，嘿嘿

[wfth]

您真是太好了，我这下总算明白了.谢谢.

[moonsuns]

但如果要重txt文件中读取浮点数，又如何操作呢！