Question

I have a class called VoucherEntity, includes a Property named “Customer”, a object of Class CustomerEntity, so I have bellow code,

<TextBox Height="23" IsReadOnly="False" HorizontalAlignment="Stretch" Margin="124,48,174,0" Name="txt_customer" VerticalAlignment="Top" Text="{Binding Path=Customer.Name}" />

in .cs file, I have bellow code

_voucher = new VoucherEntity();
this.DataContext = _voucher;

it means, at first, the Customer property is null, after clicked a button, I will give Customer property of _voucher a CustomerEntity object, then I hope the TextBox can display it immediately, but failed, what should I do?

Answer 1

If you want to except changes in your view you should notify the view about the changes.

So just implement the INotifyPropertyChanged interface in the VoucherEntity class and fire the PropertyChanged event after you set the Customer prop

public class VoucherEntity: INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

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

    private CustomerEntity _customer;
    public CustomerEntity Customer
    {
        get {return _customer;}
        set
        {
            if (_customer != value)
            {
                _customer= value;
                FirePropertyChanged("Customer");
            }
        }
    }
}