如何刷新Windows窗体控件的简单绑定？

using System.Windows.Forms;
using System.ComponentModel;

Binding binding = new Binding("Text", yourDataSource, "customerName");
textBox.DataBindings.Add(binding);

public class Customer : INotifyPropertyChanged
{
    private string _customerName;
    public string customerName
    {
        get { return _customerName; }
        set
        {
            _customerName = value;
            NotifyPropertyChanged("customerName");
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

binding.WriteValue();