Question

I am trying to learn how to use lists in C#. There are a lot of tutorials out there, but none of them really explain how to view a list that contains a record.

Here is my code:

class ObjectProperties
{
    public string ObjectNumber { get; set; }
    public string ObjectComments { get; set; }
    public string ObjectAddress { get; set; }
}

List<ObjectProperties> Properties = new List<ObjectProperties>();
ObjectProperties record = new ObjectProperties
    {
        ObjectNumber = txtObjectNumber.Text,
        ObjectComments = txtComments.Text,
        ObjectAddress = addressCombined,
    };
Properties.Add(record);

I want to display the values in a messagebox. Right now I am just making sure the information is going into the list. I also want to learn how to find a value in the list and get the other information that is related to it, such as, I want to find the item by the Object Number and if it is in the list then it will return the address. I am also using WPF, if that makes a difference. Any help will be appreciated. Thank You.

Answer 1

The best way is to override ToString in your class and use string.Join to join all your records:

var recordsAsString = string.Join(Environment.NewLine, 
            Properties.Select(p => p.ToString()));
MessagBox.Show(recordsAsString);

Here’s a possible implementation of ToString:

class ObjectProperties
{
    public string ObjectNumber { get; set; }
    public string ObjectComments { get; set; }
    public string ObjectAddress { get; set; }

    public override string ToString() 
    {
        return "ObjectNumber: " 
              + ObjectNumber 
              + " ObjectComments: " 
              + ObjectComments 
              + " ObjectAddress: " 
              + ObjectAddress;
    }
}

I also want to learn how to find a value in the list and get the other information that is related to it, such as, I want to find the item by the Object Number and if it is in the list then it will return the address.

There are several ways to search a List<T>, here are two:

String numberToFind = "1234";
String addressToFind = null;
// using List<T>.Find method
ObjectProperties obj = Properties.Find(p => p.ObjectNumber == numberToFind);
//using Enumerable.FirstOrDefault method (add using System.Linq)
obj = Properties.FirstOrDefault(p => p.ObjectNumber == numberToFind);
if (obj != null)
    addressToFind = obj.ObjectAddress;