Actual Date and Time bind to a Label

Answers

• Wednesday, June 20, 2007 8:50 AMThomas Claudius Huber

   
  

  0

  Hi Chris,

   

  the problem is that DateTime.Now has no mechanism for change-notification.

  So you need a custom solution.

   

  I would create an extra class that has only a now property and implements INotifyPropertyChanged. It could look like this:

   

  Code Snippet

  public class NotifyingDateTime:INotifyPropertyChanged

  {

  public event PropertyChangedEventHandler PropertyChanged;

  private DateTime _now;

  public NotifyingDateTime()

  {

  _now = DateTime.Now;

  DispatcherTimer timer = new DispatcherTimer();

  timer.Interval = TimeSpan.FromMilliseconds(100);

  timer.Tick += new EventHandler(timer_Tick);

  timer.Start();

  }

  public DateTime Now

  {

  get{return _now;}

  private set

  {

  _now = value;

  if(PropertyChanged!=null)

  PropertyChanged(this,new PropertyChangedEventArgs("Now"));

  }

  }

  void timer_Tick(object sender, EventArgs e)

  {

  Now = DateTime.Now;

  }

  }

   

  In your XAML-File you could then just bind to the Now-Property of this class and will get always the current date and time.

  If you need to show a different TimeFormat, you could use a ValueConverter to do that:

   

  Code Snippet

  <Window x:Class="MyApp.Window1"

  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

  xmlns:local="clr-namespace:MyApp"

  Title="MyApp" Height="300" Width="300"

  >

  <Window.Resources>

  <local:NotifyingDateTime x:Key="notifyingDate"/>

  </Window.Resources>

  <Label Content="{Binding Source={StaticResource notifyingDate},Path=Now}"/>

  </Window>

   

   

  Thomas

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