Chỉnh sửa

Chia sẻ qua

How to generate text files from XML (LINQ to XML)

This article provides an example that shows how to use C# and Visual Basic to generate a comma-separated values (CSV) text file from an XML file.

Example: Generate a CSV file from an XML document

This example generates a CSV file from XML document Sample XML file: Customers and orders.

The C# version uses method syntax and the Aggregate operator to generate the file in a single expression. For more information, see Query Syntax and Method Syntax in LINQ (C#).

The Visual Basic version uses procedural code to aggregate the collection of strings into a single string.

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);

Dim custOrd As XElement = XElement.Load("CustomersOrders.xml")
Dim strCollection As IEnumerable(Of String) = _
    From el In custOrd.<Customers>.<Customer> _
    Select _
        String.Format("{0},{1},{2},{3},{4},{5},{6},{7},{8},{9}{10}", _
            el.@CustomerID, _
            el.<CompanyName>.Value, _
            el.<ContactName>.Value, _
            el.<ContactTitle>.Value, _
            el.<Phone>.Value, _
            el.<FullAddress>.<Address>.Value, _
            el.<FullAddress>.<City>.Value, _
            el.<FullAddress>.<Region>.Value, _
            el.<FullAddress>.<PostalCode>.Value, _
            el.<FullAddress>.<Country>.Value, _
            Environment.NewLine _
        )
Dim sb As StringBuilder = New StringBuilder()
For Each str As String In strCollection
    sb.Append(str)
Next
Console.WriteLine(sb.ToString())

This example produces the following output:

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

See also