如何在MFC中读取txt文件中的数据？

[wyl1267]

很久未用VC编程了，想问个基本问题，有个test.txt文件格式如下(行数不定)：

Freq Val
--------------
50.0 -17.8
52.9 -17.6
56.0 -17.4
59.4 -16.9
63.0 -16.2

需将Freq下的数据存入freq[]数组中，将Val下的数据存入val[]数组中.
该用CStdioFile还是CFile较合适？
请写一段示范程序，谢谢！

[zyrr159487]

MFC主要读写文件的类是CFile,而CStdioFile类是派生自CFile类的，主要增加了一个按行的方式读取/写入文件每行字符串的功能
读写TXT文件，写入和输出必须统一格式
CStdioFile myFile, File;
if(myFile.Open(CBApp::getCurrModulePath()+_T("filename.txt"), CFile::modeRead))
{
//读取
myFile.ReadString(str);
myFile.Close();
}
else
{
//创建
File.Open(CBApp::getCurrModulePath()+_T("filename.txt"), CFile::modeWrite | CFile::modeCreate);
File.WriteString(sFileName);
File.Close();
}
//写入
File.Open(CBApp::getCurrModulePath()+_T("filename.txt"), CFile::modeWrite );
File.WriteString(sFileName);
File.Close();

[oyljerry]

CStdioFile刚好可以按行读取，ReadString到CString中，然后根据空格来分隔两个数据，分别放入对应的数组

[社会栋梁]

CStdioFile功能正合适
CStdioFile Class Members
Data Members

m_pStream Contains a pointer to an open file.


Construction

CStdioFile Constructs a CStdioFile object from a path or file pointer.


Text Read/Write

ReadString Reads a single line of text.
WriteString Writes a single line of text.

[wangli820]

CStdioFile myFile, File;
if(myFile.Open(CBApp::getCurrModulePath()+_T("filename.txt"), CFile::modeRead))
{
while (myFile.ReadString(str))
{
//处理读到的每一行数据
}
myFile.Close();
}

[Eleven]

#define MAX_COUNT 256

	try
	{
		CStdioFile file;
		file.Open(_T("F:\\11.txt"), CFile::modeRead);
		CString strLine(_T(""));
		CString strText(_T(""));
		LPCTSTR szToken(_T(" "));
		int curPos = 0;
		int nIndex = 0;
		double freq[MAX_COUNT] = {0};
		double val[MAX_COUNT] = {0};
		int nCount = 0;

		while(file.ReadString(strLine))
		{
			curPos = 0;
			strLine.Trim(_T(" "));
			nIndex = 0;

			if(nCount >= MAX_COUNT)
			{
				break;
			}

			while(_T("") != (strText = strLine.Tokenize(szToken, curPos)))
			{
				if(++nIndex%2)
				{
					freq[nCount] = _tcstod(strText, NULL);
				}
				else
				{
					val[nCount] = _tcstod(strText, NULL);
				}
			}
			nCount++;
		}
		file.Close();

		CString strTmp(_T(""));
		CString strMsg(_T(""));
		for(int i=0; i<nCount; i++)
		{
			strTmp.Format(_T("freq=%.1lf, val=%.1lf\r\n"), freq[i], val[i]);
			strMsg += strTmp;
		}
		AfxMessageBox(strMsg);
	}
	catch(CFileException* e)
	{
		e->ReportError();
		e->Delete();
	}

[owentjr]

学习到了

[pcgg5244]

CStdioFile file;
file.Open("test.txt",CFile::modeRead);
CString strLine;
int i=0;
float freq[100];
float val[100];
for(int j=0;j<2;j++)
file.ReadString(strLine);//MS这里得跳两行
while(file.ReadString(strLine))
{
sscanf(strLine,"%f -%f",freq+i,val+i);
i++;
}
file.Close();

[pcgg5244]

不过我觉得用FILE更方便来着
float freq[100],val[100];
FILE *fp;
fp=fopen("test.txt","r+");
int i=0;
while(!feof(fp))
{
fscanf(fp,"%f -%f\r\n",a+i,b+i);
}
fclose(fp);

[pcgg5244]

打错了
float freq[100],val[100];
FILE *fp;
fp=fopen("test.txt","r+");
int i=0;
while(!feof(fp))
{
fscanf(fp,"%f -%f\r\n",freq+i,val+i);
i++;
}
fclose(fp);

[mngzilin]

CFile

[wltg2001]

用CStdioFile吧，一行行的读，比较方便，读到CString里后，用CString::Find去找空格或是-都很方便

[wyl1267]

谢谢楼上提供了简洁的代码，我又学到两招，对于这个基础问题，还是基本的C函数管用。

[tiger12551]

终于学会了C和C++对文件读操作，谢谢