C++读取文本文件

文件内容

读取方法

• 先打开文件，按行读取
• 对每行数据按空格分割
• 格式转换

#include 
#include 
#include 
#include 
#include 

void preprocess(std::string dataPath) {
	std::fstream infile;
	infile.open(dataPath, std::ios::in);   // 打开文件
	if (!infile.is_open()) {
		std::cout << "open file " << dataPath << " failed! " << std::endl;
		return;
	}
	std::vector data;
	std::string s;
	while (std::getline(infile, s)) {     // 按行读取
		data.push_back(s);
	}

	std::vector > points;
	std::string suffix = dataPath.substr(dataPath.find_last_of('.') + 1);   // 获取文件类型
	if (suffix == "txt") {
		for (int i = 0; i < data.size(); ++i) {
			std::vector line_data;
			std::istringstream ss(data[i]);
			std::string item;
			int n = 0;
			while (n <3 && ss >> item) {                           // 按空格分割并对相应数据进行格式转换
				line_data.push_back(std::stof(item));
				n += 1;
			}
			points.push_back(line_data);
		}
	}
	else if (suffix == "pcd"){
		int skipRows = 10;
		for (int i = skipRows; i < data.size(); ++i) {
			std::vector line_data;
			std::istringstream ss(data[i]);
			std::string item;
			int n = 0;
			while (n <3 && ss >> item) {
				line_data.push_back(std::stof(item));
				n += 1;
			}
			points.push_back(line_data);
		}
	}
	else {
		std::cout << "Don't support file type, just useful for txt or pcd!";
		return;
	}
}