Binding forename and surname fields to a label?

Question

I have a table associating an ID with a client's forename and surname (two separate fields). I have a TextBox on my form for a user to enter a client ID and I'd like a live update of the name displayed on a label, e.g.:

TextBox:  1  -->  Label: "Sam Pell"    (user types 1)
TextBox: 12  -->  Label: "Andy Other"  (user types 2)

I have two questions, really - I'm new to databinding in .NET:

• How can I make the contents of the TextBox update the displayed name on the Label?
• How can I display two separate fields (concatenated) within a single Label control?

I am currently using the Visual Studio data binding components; namely a BindingSource, TableAdapter and DataSet.

Answer 1

How are you getting the values from the database? You could perhaps modify your query to concatenate the values like this;

SELECT firstName + " " + surname FROM user

So you've just got one value to contend with when databinding.

Answer 2

The type you are binding could have a readonly property that has a concatenated value.

public class Person
{
    string Forename { get; set; }
    string Surname { get; set; }
    string FullName 
    {
        get { return String.Format("{0} {1}", Forename, Surname); }
    }
}

Then bind FullName property to your label control.

In case you are using DataSet, then Add a custom column to your DataTable, with expression "forename + ' ' + surname". More info here.

To update label you have to handle TextChanged event of your text box:

textBox1.TextChanged += () => label1.Text = (string) dt.Rows.Find(textBox1.Text)["columnName"];

where column name is the name of your new column.