Procédure : générer du code XML à partir de fichiers CSV
Cet exemple montre comment utiliser LINQ (Language Integrated Query) et LINQ to XML pour générer un fichier XML à partir d'un fichier de valeurs séparées par des virgules (CSV).
Le code suivant exécute une requête LINQ sur un tableau de chaînes.
Dans la version C#, la requête utilise la clause let pour fractionner chaque chaîne en un tableau de champs.
// 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);
' Create the text file.
Dim csvString As String = "GREAL,Great Lakes Food Market,Howard Snyder,Marketing Manager,(503) 555-7555,2732 Baker Blvd.,Eugene,OR,97403,USA" & vbCrLf & _
"HUNGC,Hungry Coyote Import Store,Yoshi Latimer,Sales Representative,(503) 555-6874,City Center Plaza 516 Main St.,Elgin,OR,97827,USA" & vbCrLf & _
"LAZYK,Lazy K Kountry Store,John Steel,Marketing Manager,(509) 555-7969,12 Orchestra Terrace,Walla Walla,WA,99362,USA" & vbCrLf & _
"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.
Dim source As String() = File.ReadAllLines("cust.csv")
Dim cust As XElement = _
<Root>
<%= From strs In source _
Let fields = Split(strs, ",") _
Select _
<Customer CustomerID=<%= fields(0) %>>
<CompanyName><%= fields(1) %></CompanyName>
<ContactName><%= fields(2) %></ContactName>
<ContactTitle><%= fields(3) %></ContactTitle>
<Phone><%= fields(4) %></Phone>
<FullAddress>
<Address><%= fields(5) %></Address>
<City><%= fields(6) %></City>
<Region><%= fields(7) %></Region>
<PostalCode><%= fields(8) %></PostalCode>
<Country><%= fields(9) %></Country>
</FullAddress>
</Customer> _
%>
</Root>
Console.WriteLine(cust)
Ce code génère la sortie suivante :
<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>