使用linq读取分隔符文本文件

网络编程 2021-07-04 22:40www.168986.cn编程入门
有时我们会处理一些带分隔符数据文本文件。例如,使用”,”分隔的数据,狼蚁网站SEO优化介绍下使用linq读取分隔符文本文件的方法

如下图

然后它们存储到文本文件有这样的列

代码如下:

First Name
Last Name
Job Title
City
Country


在我们读取这个文件之前,先建一个实体类

代码如下:

/// <summary>
 /// Customer entity
/// </summary>
public class Customer{
public string Firstname { get; set; }
public string Lastname { get; set; }
public string JobTitle { get; set; }
public string City { get; set; }
public string Country { get; set; }
}

接着我们使用LINQ读取整个文件

代码如下:

var query = from line in File.ReadAllLines(filePath)
 let customerRecord = line.Split(',')
select new Customer()
 {
Firstname = customerRecord[0],
Lastname = customerRecord[1],
 JobTitle = customerRecord[2],
City = customerRecord[3],
Country = customerRecord[4]
};
 foreach (var item in query)
{
Console.WriteLine("{0}, {1}, {2}, {3}, {4}"
 , item.Firstname, item.Lastname, item.JobTitle, item.City, item.Country);
}

要读取可以带条件的记录也可以,我们filter出Country是UK:

代码如下:

 var query = from c in
(from line in File.ReadAllLines(filePath)
 let customerRecord = line.Split(',')
select new Customer()
{
Firstname = customerRecord[0],
Lastname = customerRecord[1],
 JobTitle = customerRecord[2],
City = customerRecord[3],
Country = customerRecord[4]
})
 where c.Country == "UK"
select c;


另一例子

代码如下:

var query = from c in
(from line in File.ReadAllLines(filePath)
let customerRecord = line.Split(',')
select new Customer()
{
Firstname = customerRecord[0],
Lastname = customerRecord[1],
JobTitle = customerRecord[2],
City = customerRecord[3],
Country = customerRecord[4]
})
where c.JobTitle.Contains("Sales")
select c;

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