C# WPF .xaml control data-binding question.

//Login window which passes the user object to the next window
try{
                    loginUser = SQLuserAccess.UserLogin(txtUsername.Text, txtPassword.Password.ToString());
                    if (txtUsername.Text == loginUser.Username && txtPassword.Password == loginUser.Password) {
                        if (loginUser.IsAdmin == true) {
                            Window showAdminSrc = new AdminWindow(loginUser);
                            showAdminSrc.Show();
                            Close();
                        }  else if (loginUser.IsAdmin == false){
                            Window nonAdmin = new CustomerScreen(loginUser);
                            nonAdmin.Show();
                            Close();
                        } else
                            lblInvalidText.Content = "Admin is not True or False!";
                    }
//Adminwindow screen which takes object
        public AdminWindow(User user) {
            adminUser = user;
            InitializeComponent();
            //Display specific username on window.
            TextBlockName.Text = "Hello:" + Environment.NewLine +user.Username;
        }
//The control in .xaml        <TextBlock x:Name="TextBlockName" TextWrapping="Wrap" HorizontalAlignment="Right" Margin="0,30,35,0" FontSize="16">Hello:<!--<LineBreak /><Run Text="{Binding Username}"/>--></TextBlock>
//AND HERE IS SOMETHING I WAS TRYING DATA BINDING BUT HAVE NOT FIGURED OUT      		  <!--   LEARN DATA BINDING TEXTBLOCK TO DISPLAY USER OBJECT NAME.
        <TextBlock x:Name="TextBlockUsername" Text="{Binding Username}" HorizontalAlignment="Right" FontSize="16" Margin="0,60,35,0"/>
-->