Capture Left/Right Soft Key press -- C# .net CF 3.5

Question

My application is currently running on a handheld device that is running Windows Mobile 6.5. I want to be able to capture the Left/Right soft key button presses within the application and take the User to the "home" form or another form that is used frequently inside the application. At the OS level, these soft keys are set up to go to Calendar/Contacts respectively, however inside my application I would like these buttons to do as mentioned above. How do I go about capturing or intercepting these soft key button presses inside of the Compact Framework? I have done a little research and have seen some references to registering a Hot Key? Any help would be greatly appreciated.

Side note: My application uses a MainMenu control but the left/right soft keys do not control any menu selections.

Answer 1

Normally you would only have to use AllKeys(True) api cal to capture all key presses.

But the solution to capture SoftKey1 and SoftKey2 on WM6.5 is more complicated: http://www.hjgode.de/wp/2012/09/20/windows-mobile-cf-how-to-catch-f1-and-f2-in-weh/

Excerpt of my blog there:

• Using a Microsoft.WindowsCE.Forms MessageWindow with a WndProc fails. [CF MessageWindow approach]
• Using SetWindowLong with a WndProc replacement fails, if used only on the form handle. But you may use that and implement it for every child element in the form. It looks like the messages are not routed thru the main fom WndProc (see native winapi below), or lets say, the F1 and F2 keys do not bubble from child to parent as seen in a Win32 API window application. [Subclassing approach]
• using OpenNetCF Application2/ApplicationEx and an IMessageFilter works. If you already use or see other needs for OpenNetCF/SmartDeviceFramework, you may use this approach. [SmartDeviceFramework Application2/IMessageFilter approach] using a global keyboard hook works. That is the one I prefer, as it easy to use and gives all keyboard messages. [KeybdHook approach]

Answer 2

try this:

public class HButtons : System.Windows.Forms.Form
{
    private MainMenu mainMenu1;
    private MenuItem mnuBack;
    myMessageWindow messageWindow;

    public HButtons()
    {
        InitializeComponent();

        this.messageWindow = new myMessageWindow(this); 
        RegisterHKeys.RegisterRecordKey(this.messageWindow.Hwnd);
    }
    protected override void Dispose(bool disposing)
    {
        RegisterHKeys.UnRegisterRecordKey();
         base.Dispose(disposing);
    }

    public void ButtonPressed(int button)
    {
        switch (button)
            {
                case (int)KeysHardware.VK_APP1:
                    MessageBox.Show("VK_APP1 pressed!");
                    break;
                case (int)KeysHardware.GreenPhoneButton:
                    MessageBox.Show("GreenPhoneButton pressed!");
                    break;
                case (int)KeysHardware.RedPhoneButton:
                    MessageBox.Show("RedPhoneButton pressed!");
                    break;

                case (int)KeysHardware.VK_TSOFT1:
                    MessageBox.Show("VK_TSOFT1 pressed!");
                    break;

            }
        }

        private void InitializeComponent()
        {
            this.mainMenu1 = new System.Windows.Forms.MainMenu();
            this.mnuBack = new System.Windows.Forms.MenuItem();
            this.SuspendLayout();
            // 
            // mainMenu1
            // 
            this.mainMenu1.MenuItems.Add(this.mnuBack);
            // 
            // mnuBack
            // 
            this.mnuBack.Text = "Back";
            this.mnuBack.Click += new System.EventHandler(this.mnuBack_Click);
            // 
            // HButtons
            // 
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Inherit;
            this.ClientSize = new System.Drawing.Size(240, 268);
            this.Menu = this.mainMenu1;
            this.MinimizeBox = false;
            this.Name = "HButtons";
            this.Text = "HW buttons";
            this.ResumeLayout(false);

        }

        private void mnuBack_Click(object sender, EventArgs e)
        {
            this.Close();
        }
    }

    public class myMessageWindow : MessageWindow
    {
        public const int WM_HOTKEY = 0x0312;
        HButtons example;
        public myMessageWindow(HButtons anExample)
        {
            this.example = anExample;
        }
        protected override void WndProc(ref Message msg)
        {
            switch (msg.Msg)
            {
                case WM_HOTKEY:
                    example.ButtonPressed(msg.WParam.ToInt32());
                    return;
            }
            base.WndProc(ref msg);
        }
    }

    public class RegisterHKeys
    {
        [DllImport("coredll.dll", SetLastError = true)]
        public static extern bool RegisterHotKey(
            IntPtr hWnd, // handle to window
            int id, // hot key identifier
            KeyModifiers Modifiers, // key-modifier options
            int key //virtual-key code
        );

        [DllImport("coredll.dll")]
        private static extern bool UnregisterFunc1(
            KeyModifiers modifiers, 
            int keyID);

        public static void RegisterRecordKey(IntPtr hWnd)
        {
            UnregisterFunc1(KeyModifiers.Windows, (int)KeysHardware.VK_APP1);
            RegisterHotKey(hWnd, (int)KeysHardware.VK_APP1, KeyModifiers.Windows, (int)KeysHardware.VK_APP1);

            UnregisterFunc1(KeyModifiers.None, (int)KeysHardware.GreenPhoneButton);
            RegisterHotKey(hWnd, (int)KeysHardware.GreenPhoneButton, KeyModifiers.None, (int)KeysHardware.GreenPhoneButton);

            UnregisterFunc1(KeyModifiers.None, (int)KeysHardware.RedPhoneButton);
            RegisterHotKey(hWnd, (int)KeysHardware.RedPhoneButton, KeyModifiers.None, (int)KeysHardware.RedPhoneButton);

            UnregisterFunc1(KeyModifiers.None, (int)KeysHardware.VK_TSOFT1);
            RegisterHotKey(hWnd, (int)KeysHardware.VK_TSOFT1, KeyModifiers.None, (int)KeysHardware.VK_TSOFT1);

        }

        public static void UnRegisterRecordKey()
        {
            UnregisterFunc1(KeyModifiers.Windows, (int)KeysHardware.VK_APP1);
            UnregisterFunc1(KeyModifiers.None, (int)KeysHardware.GreenPhoneButton);
            UnregisterFunc1(KeyModifiers.None, (int)KeysHardware.RedPhoneButton);
            UnregisterFunc1(KeyModifiers.None, (int)KeysHardware.VK_TSOFT1);
        }
    }

    ///// <summary>
    ///// Summary description for hwButtons.
    ///// </summary>
    //public class hwButtons
    //{
    //    public hwButtons()
    //    {
    //        HButtons theBtns = new HButtons();
    //    }
    //}

    public enum KeyModifiers
    {
        None = 0,
        Alt = 1,
        Control = 2,
        Shift = 4,
        Windows = 8,
        Modkeyup = 0x1000,
    }
    //public enum KeysHardware : int
    //{
    //    Hardware1 = 193, //0xC1
    //    Hardware2 = 194,
    //    Hardware3 = 195,
    //    Hardware4 = 196,
    //    Hardware5 = 197
    //}

    public enum KeysHardware : int
    {
        VK_F1 = 0x70,
        VK_F2 = 0x71,
        VK_F3 = 0x72,
        VK_F4 = 0x73,
        VK_F5 = 0x74,
        VK_F6 = 0x75,
        VK_F7 = 0x76,
        VK_F8 = 0x77,
        VK_F9 = 0x78,
        VK_F10 = 0x79,
        VK_F11 = 0x7A,
        VK_F12 = 0x7B,
        VK_TSOFT1 = VK_F1, // Softkey 1
        VK_TSOFT2 = VK_F2, // Softkey 2
        VK_TTALK = VK_F3, // Talk = Green Phone Button
        VK_TEND = VK_F4, // End = Red Phone Button
        VK_APP1 = 0xC1, // up to 6 other hardware buttons
        VK_APP2 = 0xC2,
        VK_APP3 = 0xC3,
        VK_APP4 = 0xC4,
        VK_APP5 = 0xC5,
        VK_APP6 = 0xC6,

        RedPhoneButton = VK_TEND,
        GreenPhoneButton = VK_TTALK
    }