How to determine whether my application is active (has focus)

Question

Is there a way to tell whether my application is active i.e. any of its windows has .IsActive=true?

I\'m writing messenger app and want it to flash in taskbar when it is

Answer 1

You have the Activated and Deactivated events of Application.

If you want to be able to Bind to IsActive you can add a Property in App.xaml.cs

of course you can also access this property in code like

App application = Application.Current as App;
bool isActive = application.IsActive;

App.xaml.cs

public partial class App : Application, INotifyPropertyChanged
{
    private bool m_isActive;
    public bool IsActive
    {
        get { return m_isActive; }
        private set
        {
            m_isActive = value;
            OnPropertyChanged("IsActive");
        }
    }

    protected override void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);
        Activated += (object sender, EventArgs ea) =>
        {
            IsActive = true;
        };
        Deactivated += (object sender, EventArgs ea) =>
        {
            IsActive = false;
        };
    }


    public event PropertyChangedEventHandler PropertyChanged;
    private void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}