Question

How to to write .xml file with this string?

string:

string string1 = textbox1.text;
string string2 = textbox2.text;
string string3 = textbox3.text;
string string4 = textbox4.text;

the xml file result:

<?xml version="1.0" encoding="utf-8" ?>
        <books>
            <book Title="Pure JavaScript" Price=string1/>
            <book Title="Effective C++" Price=string2/>
            <book Title="Assembly Language: Step-By-Step" Price=string3/>
            <book Title="Oracle PL/SQL Best Practices" Price=string4/>
        </books>

Answer 1

You can use Linq to XML for this. Suppose you have a class Book:

class Book
{
    public string Title { get; set; }
    public decimal Price { get; set; }
}

And now you have a list of books that you want to put into an XML document:

List<Book> books = new List<Book>();
books.Add(new Book() { Title = "Pure JavaScript", Price = 59.0M});

XDocument xdoc = new XDocument(new XElement("books", books.Select( x=> new XElement("book", 
                               new XAttribute("Title", x.Title), 
                               new XAttribute("Price", x.Price)))));

Now you can just save this XDocument:

xdoc.Save("text.xml");

This produces:

<books>
  <book Title="Pure JavaScript" Price="59.0" />
</books>