Question

I have a c# program using WPF. I have it that when you press a key, it will click on a button and then disable the button. My issue is that, once I decide to click on a button, the keyDown event no longer gets executed. Am I missing something?

namespace FindTheCat
{
    public partial class MainWindow : Window
    {
        private Treasure treas;

        public MainWindow()
        {
            InitializeComponent();
        }

        private void checkForKitty(object sender, RoutedEventArgs e)
        {
            ToggleButton button = (ToggleButton)e.OriginalSource;

            if(button != null)
            {
                button.IsEnabled = false;

                int loc = getLocation((String)button.Content);

                if (loc > 0)
                {
                    isFound(loc);
                }
            }
        }

        private void checkKey(object sender, KeyEventArgs e)
        {
            ToggleButton item = (ToggleButton)GridRoot.FindName(e.Key.ToString());
            if (item != null)
            {
                item.IsEnabled = false;
                int loc = getLocation(e.Key.ToString());

                if (loc > 0)
                {
                    isFound(loc);
                }
            }

            MessageBox.Show("Key Pressed");
        }

        private void isFound(int loc)
        {
            Boolean found = treas.isFound(loc);

            if (found)
            {
                MessageBox.Show("YAY! You found the cat!");
                Reset();
            }
            else
            {
                MessageBox.Show("Boo! You did not find the cat!");
            }
        }

        private int getLocation(String letter)
        {
            switch (letter)
            {
                case "A":
                    return 1;
                case "B":
                    return 2;
                case "C":
                    return 3;
                case "D":
                    return 4;
                case "E":
                    return 5;
                case "F":
                    return 6;
                case "G":
                    return 7;
                case "H":
                    return 8;
                case "I":
                    return 9;
                case "J":
                    return 10;
                case "K":
                    return 11;
                case "L":
                    return 12;
                case "M":
                    return 13;
                case "N":
                    return 14;
                case "O":
                    return 15;
                case "P":
                    return 16;
                case "Q":
                    return 17;
                case "R":
                    return 18;
                case "S":
                    return 19;
                case "T":
                    return 20;
                case "U":
                    return 21;
                case "V":
                    return 22;
                case "W":
                    return 23;
                case "X":
                    return 24;
                case "Y":
                    return 25;
                default:
                    return 0;
            }
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            treas = new Treasure();
        }

        private void Reset()
        {
            treas.Reset();

            ResetButton("A");
            ResetButton("B");
            ResetButton("C");
            ResetButton("D");
            ResetButton("E");
            ResetButton("F");
            ResetButton("G");
            ResetButton("H");
            ResetButton("I");
            ResetButton("J");
            ResetButton("K");
            ResetButton("L");
            ResetButton("M");
            ResetButton("N");
            ResetButton("O");
            ResetButton("P");
            ResetButton("Q");
            ResetButton("R");
            ResetButton("S");
            ResetButton("T");
            ResetButton("U");
            ResetButton("V");
            ResetButton("W");
            ResetButton("X");
            ResetButton("Y");
        }

        private void ResetButton(String name)
        {
            ToggleButton item = (ToggleButton)GridRoot.FindName(name);

            if (item != null)
            {
                item.IsEnabled = true;
                item.IsChecked = false;
            }
        }
    }
}

Answer 1

A disabled control can not have the keyboard focus. So it won’t get any key events.