private void Frame_BackKeyPress(object s, CancelEventArgs e)
{
var eventArgs = new NavigationServiceBackKeyPressedEventArgs();
RaiseBackKeyPressed(eventArgs);
switch (eventArgs.Behavior)
{
case NavigationServiceBackKeyPressedBehavior.GoBack:
break;
case NavigationServiceBackKeyPressedBehavior.HideApp:
ExceptionHelper.ThrowNotSupported();
break;
case NavigationServiceBackKeyPressedBehavior.ExitApp:
e.Cancel = true;
Application.Current.Terminate();
break;
case NavigationServiceBackKeyPressedBehavior.DoNothing:
e.Cancel = true;
break;
default:
throw new ArgumentOutOfRangeException();
}
}
/// <summary>
/// Raises the <see cref="BackKeyPressed"/> event with the provided event data.
/// </summary>
/// <param name="eventArgs">The event data.</param>
protected virtual void RaiseBackKeyPressed(NavigationServiceBackKeyPressedEventArgs eventArgs)
{
var eventHandler = BackKeyPressed;
if (eventHandler != null)
{
eventHandler(this, eventArgs);
}
}
private bool HandleBackKeyPress()
{
var handled = GetMasterDetailView()?.HandleBackKeyPress() ?? false;
if (!handled)
{
var eventArgs = new NavigationServiceBackKeyPressedEventArgs();
RaiseBackKeyPressed(eventArgs);
switch (eventArgs.Behavior)
{
case NavigationServiceBackKeyPressedBehavior.GoBack:
var frame = GetFrame();
if (frame?.CanGoBack ?? false)
{
frame.GoBack();
handled = true;
}
break;
case NavigationServiceBackKeyPressedBehavior.HideApp:
break;
case NavigationServiceBackKeyPressedBehavior.ExitApp:
handled = true;
Application.Current?.Exit();
break;
case NavigationServiceBackKeyPressedBehavior.DoNothing:
handled = true;
break;
default:
throw new ArgumentOutOfRangeException();
}
}
return(handled);
}
/// <summary>
/// Raises the <see cref="BackKeyPressed"/> event with the provided event data.
/// </summary>
/// <param name="eventArgs">The event data.</param>
protected virtual void RaiseBackKeyPressed(NavigationServiceBackKeyPressedEventArgs eventArgs)
{
BackKeyPressed?.Invoke(this, eventArgs);
}
private void NavigationServiceOnBackKeyPressed(object sender, NavigationServiceBackKeyPressedEventArgs e)
{
e.Behavior = NavigationServiceBackKeyPressedBehavior.GoBack;
}