Type to search in Windows 8

In het startscherm kan je gaan typen om te gaan zoeken in een applicatie. Dit gedrag is ook heel eenvoudig in je applicatie te realiseren, maar er zit een maar aan. De meest voor de handliggende oplossing op keydown van het core window het searchpane openen:

Window.Current.CoreWindow.KeyDown += CoreWindow_KeyDown;

void CoreWindow_KeyDown(Windows.UI.Core.CoreWindow sender, Windows.UI.Core.KeyEventArgs args)
{
      SearchPane.GetForCurrentView().Show();
}

 Echter zal je zien met deze oplossing dat je altijd de eerste toetsaanslag mist in de seearch query. Dit is onhandig. Best is om de event handler iets uit te breiden en zelf de eerste toetsenbord aanslag af te handelen:

void CoreWindow_KeyUp(Windows.UI.Core.CoreWindow sender, Windows.UI.Core.KeyEventArgs args)
        {

            if ((int)args.VirtualKey >= 48 && (int)args.VirtualKey <= 90)
            {
                string text = string.Empty;

                switch (args.VirtualKey)
                {
                    case Windows.System.VirtualKey.Number0:
                        text = "0";
                        break;
                    case Windows.System.VirtualKey.Number1:
                        text = "1";
                        break;
                    case Windows.System.VirtualKey.Number2:
                        text = "2";
                        break;
                    case Windows.System.VirtualKey.Number3:
                        text = "3";
                        break;
                    case Windows.System.VirtualKey.Number4:
                        text = "4";
                        break;
                    case Windows.System.VirtualKey.Number5:
                        text = "5";
                        break;
                    case Windows.System.VirtualKey.Number6:
                        text = "6";
                        break;
                    case Windows.System.VirtualKey.Number7:
                        text = "7";
                        break;
                    case Windows.System.VirtualKey.Number8:
                        text = "8";
                        break;
                    case Windows.System.VirtualKey.Number9:
                        text = "9";
                        break;
                    case Windows.System.VirtualKey.A:
                    case Windows.System.VirtualKey.B:
                    case Windows.System.VirtualKey.C:
                    case Windows.System.VirtualKey.D:
                    case Windows.System.VirtualKey.E:
                    case Windows.System.VirtualKey.F:
                    case Windows.System.VirtualKey.G:
                    case Windows.System.VirtualKey.H:
                    case Windows.System.VirtualKey.I:
                    case Windows.System.VirtualKey.J:
                    case Windows.System.VirtualKey.K:
                    case Windows.System.VirtualKey.L:
                    case Windows.System.VirtualKey.M:
                    case Windows.System.VirtualKey.N:
                    case Windows.System.VirtualKey.O:
                    case Windows.System.VirtualKey.P:
                    case Windows.System.VirtualKey.Q:
                    case Windows.System.VirtualKey.R:
                    case Windows.System.VirtualKey.S:
                    case Windows.System.VirtualKey.T:
                    case Windows.System.VirtualKey.U:
                    case Windows.System.VirtualKey.V:
                    case Windows.System.VirtualKey.W:
                    case Windows.System.VirtualKey.X:
                    case Windows.System.VirtualKey.Y:
                    case Windows.System.VirtualKey.Z:
                        text = args.VirtualKey.ToString().ToLower();
                        break;
                }


                if ((Window.Current.CoreWindow.GetKeyState(Windows.System.VirtualKey.Shift) & Windows.UI.Core.CoreVirtualKeyStates.Down) == Windows.UI.Core.CoreVirtualKeyStates.Down ||
                    (Window.Current.CoreWindow.GetKeyState(Windows.System.VirtualKey.CapitalLock) & Windows.UI.Core.CoreVirtualKeyStates.Locked) == Windows.UI.Core.CoreVirtualKeyStates.Locked)
                {
                    text = text.ToUpper();
                }

                SearchPane.GetForCurrentView().Show(text);
                Frame.Navigate(typeof(SearchPageView), text);
            }
        }