下面的代码对字符串数组执行 LINQ 查询。

在 C# 版本中，该查询使用 let 子句将每个字符串分隔成字段数组。

C#VB

// Create the text file.

string csvString = @"GREAL,Great Lakes Food Market,Howard Snyder,Marketing Manager,(503) 555-7555,2732 Baker Blvd.,Eugene,OR,97403,USA

HUNGC,Hungry Coyote Import Store,Yoshi Latimer,Sales Representative,(503) 555-6874,City Center Plaza 516 Main St.,Elgin,OR,97827,USA

LAZYK,Lazy K Kountry Store,John Steel,Marketing Manager,(509) 555-7969,12 Orchestra Terrace,Walla Walla,WA,99362,USA

LETSS,Let's Stop N Shop,Jaime Yorres,Owner,(415) 555-5938,87 Polk St. Suite 5,San Francisco,CA,94117,USA";

File.WriteAllText("cust.csv", csvString);

// Read into an array of strings.

string[] source = File.ReadAllLines("cust.csv");

XElement cust = new XElement("Root",

    from str in source

    let fields = str.Split(',')

    select new XElement("Customer",

        new XAttribute("CustomerID", fields[0]),

        new XElement("CompanyName", fields[1]),

        new XElement("ContactName", fields[2]),

        new XElement("ContactTitle", fields[3]),

        new XElement("Phone", fields[4]),

        new XElement("FullAddress",

            new XElement("Address", fields[5]),

            new XElement("City", fields[6]),

            new XElement("Region", fields[7]),

            new XElement("PostalCode", fields[8]),

            new XElement("Country", fields[9])

        )

    )

);

Console.WriteLine(cust);

这段代码产生以下输出：

XML

<Root>

  <Customer CustomerID="GREAL">

    <CompanyName>Great Lakes Food Market</CompanyName>

    <ContactName>Howard Snyder</ContactName>

    <ContactTitle>Marketing Manager</ContactTitle>

    <Phone>(503) 555-7555</Phone>

    <FullAddress>

      <Address>2732 Baker Blvd.</Address>

      <City>Eugene</City>

      <Region>OR</Region>

      <PostalCode>97403</PostalCode>

      <Country>USA</Country>

    </FullAddress>

  </Customer>

  <Customer CustomerID="HUNGC">

    <CompanyName>Hungry Coyote Import Store</CompanyName>

    <ContactName>Yoshi Latimer</ContactName>

    <ContactTitle>Sales Representative</ContactTitle>

    <Phone>(503) 555-6874</Phone>

    <FullAddress>

      <Address>City Center Plaza 516 Main St.</Address>

      <City>Elgin</City>

      <Region>OR</Region>

      <PostalCode>97827</PostalCode>

      <Country>USA</Country>

    </FullAddress>

  </Customer>

  <Customer CustomerID="LAZYK">

    <CompanyName>Lazy K Kountry Store</CompanyName>

    <ContactName>John Steel</ContactName>

    <ContactTitle>Marketing Manager</ContactTitle>

    <Phone>(509) 555-7969</Phone>

    <FullAddress>

      <Address>12 Orchestra Terrace</Address>

      <City>Walla Walla</City>

      <Region>WA</Region>

      <PostalCode>99362</PostalCode>

      <Country>USA</Country>

    </FullAddress>

  </Customer>

  <Customer CustomerID="LETSS">

    <CompanyName>Let's Stop N Shop</CompanyName>

    <ContactName>Jaime Yorres</ContactName>

    <ContactTitle>Owner</ContactTitle>

    <Phone>(415) 555-5938</Phone>

    <FullAddress>

      <Address>87 Polk St. Suite 5</Address>

      <City>San Francisco</City>

      <Region>CA</Region>

      <PostalCode>94117</PostalCode>

      <Country>USA</Country>

    </FullAddress>

  </Customer>

</Root>

本示例的 C# 版本使用方法语法和 Aggregate 运算符通过一个表达式从 XML 文档生成 CSV 文件。 有关更多信息，请参见LINQ 中的查询语法和方法语法 (C#)。

Visual Basic 版本使用过程代码将字符串集合聚合为一个字符串。

本示例使用下面的 XML 文档：示例 XML 文件：Customers 和 Orders (LINQ to XML)。

C#VB

XElement custOrd = XElement.Load("CustomersOrders.xml");

string csv =

    (from el in custOrd.Element("Customers").Elements("Customer")

    select

        String.Format("{0},{1},{2},{3},{4},{5},{6},{7},{8},{9}{10}",

            (string)el.Attribute("CustomerID"),

            (string)el.Element("CompanyName"),

            (string)el.Element("ContactName"),

            (string)el.Element("ContactTitle"),

            (string)el.Element("Phone"),

            (string)el.Element("FullAddress").Element("Address"),

            (string)el.Element("FullAddress").Element("City"),

            (string)el.Element("FullAddress").Element("Region"),

            (string)el.Element("FullAddress").Element("PostalCode"),

            (string)el.Element("FullAddress").Element("Country"),

            Environment.NewLine

        )

    )

    .Aggregate(

        new StringBuilder(),

        (sb, s) => sb.Append(s),

        sb => sb.ToString()

    );

Console.WriteLine(csv);

这段代码产生以下输出：

GREAL,Great Lakes Food Market,Howard Snyder,Marketing Manager,(503) 555-7555,2732 Baker Blvd.,Eugene,OR,97403,USA

HUNGC,Hungry Coyote Import Store,Yoshi Latimer,Sales Representative,(503) 555-6874,City Center Plaza 516 Main St.,Elgin,OR,97827,USA

LAZYK,Lazy K Kountry Store,John Steel,Marketing Manager,(509) 555-7969,12 Orchestra Terrace,Walla Walla,WA,99362,USA

LETSS,Let's Stop N Shop,Jaime Yorres,Owner,(415) 555-5938,87 Polk St. Suite 5,San Francisco,CA,94117,USA