stringstream实例

stringstream的具体作用稍后来总结，这里分享一个实例，从txt文档中读取数据，并对进行处理。

#include <iostream>

#include <sstream>  //stringstream的头文件

#include <fstream>

#include <vector>

#include <string>

using namespace std;



void main()

{

	ifstream fin("d:\\desk\\face detection\\dataset\\train\\trainImageList.txt");

	ofstream fout("d:\\desk\\face detection\\dataset\\train\\trainImageList1.txt");

	char p_data[1024] = { 0 };

	string filename;

	while (fin.getline(p_data, sizeof(p_data)))

	{

		vector<double> data;

		//stringstream resizeData;

		//resizeData.str(p_data);

		stringstream resizeData(p_data);  //依照空格将数据分段

		resizeData >> filename;  //向filename流中写入值

		while (resizeData)      //数据流输完后就结束

		{

			string a;

			resizeData >> a;

			data.push_back(atof(a.c_str()));

		}

		

		//data[0] 不变

		double temp = data[1];

		data[1] = data[2];

		data[2] = data[3];

		data[3] = temp;



		//使其为一个正方形

		double w, h;

		double differenceValue = 0.0;

		w = data[2] - data[0];

		h = data[3] - data[1];

		differenceValue = abs(w - h);

		if (w > h)

			data[3] += differenceValue;

		else

			data[2] += differenceValue;



		fout << filename << " ";

		vector<double>::iterator it = data.begin();

		for (; it != data.end()-1; it++)

		{

			fout << *it << " ";

		}

		fout << endl;

	}

}