wpf - Binding to DateTime.Now. Update the value

Question

Well, I needed to bind DateTime.Now to a TextBlock, I used that:

 Text="{Binding Source={x:Static System:DateTime.Now},StringFormat='HH:mm:ss tt'}"

Now, how to force it to update? It get's the time when control is loaded and wouldn't update it...

Answer 1

Here's a link of a 'Ticker' class that uses INotifyPropertyChanged so it'll auto-update. Here's the code from the site:

namespace TheJoyOfCode.WpfExample
{
    public class Ticker : INotifyPropertyChanged
    {
        public Ticker()
        {
            Timer timer = new Timer();
            timer.Interval = 1000; // 1 second updates
            timer.Elapsed += timer_Elapsed;
            timer.Start();
        }

        public DateTime Now
        {
            get { return DateTime.Now; }
        }

        void timer_Elapsed(object sender, ElapsedEventArgs e)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs("Now"));
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }
}


<Page.Resources>
   <src:Ticker x:Key="ticker" />
</Page.Resources>

<TextBox Text="{Binding Source={StaticResource ticker}, Path=Now, Mode=OneWay}"/>

---

Declare:

xmlns:sys="clr-namespace:System;assembly=mscorlib"

Now this will work:

<TextBox Text="{Binding Source={StaticResource ticker}, Path=Now, Mode=OneWay}"/>