Question

Working on a application which reads some values from an customers.xml file to UI.

Linq to xml code:

var Settings = (from e in customer.Descendants("appSettings")
                                   from kvpair in e.Elements("Name")
                                   select new
                                   {
                                       Name = kvpair.Attribute("Zip").Value,
                                       Node = kvpair
                                   }).ToDictionary(x => x.Name, y => y);

txtFName.Text==Settings["CustomerA"].Node.attribute("value").Value;
txtLName=Settings["CustomerB"].Node.attribute("value").Value;

I am able to get the values into GUI from XMl file by the above code.

My question is when i comment out any element or data from xml file of a particular customer i get the error “the given key is not present in the dictionary”

How do i dynamically check whether a key exists in dictionary if then only read that value or else got to the next value ?

Answer 1

if (Settings.ContainsKey("CustomerA"))
{
   txtLName.Text = Settings["CustomerA"].Node.attribute("value").Value;
}

EDIT:

You can loop through keys accessing Keys property collection:

foreach (var key in Settings.Keys)
{
   // ..
}

Also you can use LINQ to filter out what you need:

IList<string> filteredKeys = new List<string> { "A", "B" };
Settings.Where(kv => filteredKeys.Contains(kv.Key));