Question

i have an XML file like this

     <?xml version="1.0" encoding="utf-8" ?> 
 <conStr>
  <server>192.168.1.25;</server> 
  <initial_catalog>chargdb;</initial_catalog> 
  <uid>sa;</uid> 
  <pwd>1;</pwd> 
  </conStr>

and i’m using this code for fetch data from this file :

        XmlDocument xd = new XmlDocument();
        xd.Load(Application.StartupPath + @"\cng.xml");
        string conStr = string.Empty;
        conStr += "server=";
        conStr +=xd.DocumentElement.ChildNodes[0].Attributes["server"].Value;
        conStr += "initial catalog=";
        conStr += xd.DocumentElement.ChildNodes[0].Attributes["initial_catalog"].Value;
        conStr += "uid=";
        conStr += xd.DocumentElement.ChildNodes[0].Attributes["uid"].Value;
        conStr += "pwd=";
        conStr += xd.DocumentElement.ChildNodes[0].Attributes["pwd"].Value;
        MessageBox.Show(conStr);

but each time i give an error message like this: “Object reference not set to an instance of an object.”
please help me, what can i do to read my file? thanks

Answer 1

Your existing code is looking for attributes within the <server> element. That’s not going to work, as you should be looking for elements within the root element.

I would make two changes:

• Use LINQ to XML to fetch the values
• Build the connection string using SqlConnectionStringBuilder instead of as a string

So something like this:

XDocument doc = XDocument.Load(...);
var root = doc.Root;
var builder = new SqlConnectionStringBuilder
{
    DataSource = root.Element("server").Value,
    InitialCatalog = root.Element("initial_catalog").Value,
    UserID = root.Element("uid").Value,
    Password = root.Element("pwd").Value
};
var connectionString = builder.ToString();