Windows Form C# mouse hover, mouse leave verses touchstart, touchend

Question

I have a Windows Form project in C#, for example I have events like mouse hover over picture box and mouse leave from a

picture box. My question is in a case of using a tablet or a phone or touch screen monitor and no mouse is present, I would like

to have an option of touch start (similar to a mouse hover) and touch end (similar to a mouse leave event) . Of course in stead of

using a mouse, one would use a finger. Not sure how to add this event to Windows Form C# project? Since I had before a mouse

click and mouse double click, but I simply replaced with "click and double click" and it still worked. But I do not know if I just can

replace for touch start and touch end events or I have to add to the project?

Write back, thanks in advance.

Answer

@Gennady Gurin ,Sorry for the late response, you could paste the code in the winform directly like the following code:

   namespace WindowsFormsApp1  
{  
    public partial class Form1 : Form  
    {  
        public Form1()  
        {  
            InitializeComponent();  
        }  
        protected override void WndProc(ref Message m)  
        {  
            switch (m.Msg)  
            {  
                  
                case Win32.WM_POINTERDOWN:  
                case Win32.WM_POINTERUP:  
                case Win32.WM_POINTERUPDATE:  
                case Win32.WM_POINTERCAPTURECHANGED:  
                    break;  
  
                default:  
                    base.WndProc(ref m);  
                    return;  
            }  
            int pointerID = Win32.GET_POINTER_ID(m.WParam);  
            Win32.POINTER_INFO pi = new Win32.POINTER_INFO();  
            if (!Win32.GetPointerInfo(pointerID, ref pi))  
            {  
                Win32.CheckLastError();  
            }  
            Point pt = PointToClient(pi.PtPixelLocation.ToPoint());  
            MouseEventArgs me = new MouseEventArgs(System.Windows.Forms.MouseButtons.Left, 1, pt.X, pt.Y, 0);  
            switch (m.Msg)  
            {  
                case Win32.WM_POINTERDOWN:  
                    Console.WriteLine("TOCOU" + pt);  
                    (Parent as Form1).Form1_MouseDown((this as object), me);  
                    break;  
  
                case Win32.WM_POINTERUP:  
                    Console.WriteLine("LEVANTOU");  
                    (Parent as Form1).Form1_MouseUp((this as object), me);  
                    break;  
  
                case Win32.WM_POINTERUPDATE:  
                    Console.WriteLine("UPDATE");  
                    (Parent as Form1).Form1_MouseMove((this as object), me);  
                    break;  
            }  
        }  
  
        private void Form1_MouseDown(object sender, MouseEventArgs e)  
        {  
  
        }  
  
        private void Form1_MouseUp(object sender, MouseEventArgs e)  
        {  
  
        }  
  
        private void Form1_MouseMove(object sender, MouseEventArgs e)  
        {  
  
        }  
    }  
  
  
     
  
  
}

Win32 class:

 [System.Security.SuppressUnmanagedCodeSecurity()]  
        public static class Win32  
        {  
            //------------------------------------------------------------------  
            static object _lockObj = new object();  
      
            internal static int GET_POINTER_ID(IntPtr wParam)  
            {  
                return LOWORD(wParam);  
            }  
            internal static int HIWORD(IntPtr wParam)  
            {  
                return (int)((wParam.ToInt64() >> 16) & 0xffff);  
            }  
      
            internal static int LOWORD(IntPtr wParam)  
            {  
                return (int)(wParam.ToInt64() & 0xffff);  
            }  
      
            internal static void CheckLastError()  
            {  
                int errCode = Marshal.GetLastWin32Error();  
                if (errCode != 0)  
                {  
                    throw new Win32Exception(errCode);  
                }  
            }  
      
            #region ** pointer constants  
      
            internal const int  
      
                WM_PARENTNOTIFY = 0x0210,  
                WM_NCPOINTERUPDATE = 0x0241,  
                WM_NCPOINTERDOWN = 0x0242,  
                WM_NCPOINTERUP = 0x0243,  
                WM_POINTERUPDATE = 0x0245,  
                WM_POINTERDOWN = 0x0246,  
                WM_POINTERUP = 0x0247,  
                WM_POINTERENTER = 0x0249,  
                WM_POINTERLEAVE = 0x024A,  
                WM_POINTERACTIVATE = 0x024B,  
                WM_POINTERCAPTURECHANGED = 0x024C,  
                WM_POINTERWHEEL = 0x024E,  
                WM_POINTERHWHEEL = 0x024F,  
      
                // WM_POINTERACTIVATE return codes  
                PA_ACTIVATE = 1,  
                PA_NOACTIVATE = 3,  
      
                MAX_TOUCH_COUNT = 256;  
      
            internal enum POINTER_INPUT_TYPE  
            {  
                POINTER = 0x00000001,  
                TOUCH = 0x00000002,  
                PEN = 0x00000003,  
                MOUSE = 0x00000004  
            }  
      
            [Flags]  
            internal enum POINTER_FLAGS  
            {  
                NONE = 0x00000000,  
                NEW = 0x00000001,  
                INRANGE = 0x00000002,  
                INCONTACT = 0x00000004,  
                FIRSTBUTTON = 0x00000010,  
                SECONDBUTTON = 0x00000020,  
                THIRDBUTTON = 0x00000040,  
                FOURTHBUTTON = 0x00000080,  
                FIFTHBUTTON = 0x00000100,  
                PRIMARY = 0x00002000,  
                CONFIDENCE = 0x00004000,  
                CANCELED = 0x00008000,  
                DOWN = 0x00010000,  
                UPDATE = 0x00020000,  
                UP = 0x00040000,  
                WHEEL = 0x00080000,  
                HWHEEL = 0x00100000,  
                CAPTURECHANGED = 0x00200000,  
            }  
      
            [Flags]  
            internal enum VIRTUAL_KEY_STATES  
            {  
                NONE = 0x0000,  
                LBUTTON = 0x0001,  
                RBUTTON = 0x0002,  
                SHIFT = 0x0004,  
                CTRL = 0x0008,  
                MBUTTON = 0x0010,  
                XBUTTON1 = 0x0020,  
                XBUTTON2 = 0x0040  
            }  
      
      
      
            [Flags]  
            internal enum TOUCH_FLAGS  
            {  
                NONE = 0x00000000  
            }  
      
            [Flags]  
            internal enum TOUCH_MASK  
            {  
                NONE = 0x00000000,  
                CONTACTAREA = 0x00000001,  
                ORIENTATION = 0x00000002,  
                PRESSURE = 0x00000004,  
            }  
      
            [Flags]  
            internal enum PEN_FLAGS  
            {  
                NONE = 0x00000000,  
                BARREL = 0x00000001,  
                INVERTED = 0x00000002,  
                ERASER = 0x00000004,  
            }  
      
            [Flags]  
            internal enum PEN_MASK  
            {  
                NONE = 0x00000000,  
                PRESSURE = 0x00000001,  
                ROTATION = 0x00000002,  
                TILT_X = 0x00000004,  
                TILT_Y = 0x00000008,  
            }  
      
            [Flags]  
            internal enum POINTER_MESSAGE_FLAG  
            {  
                NEW = 0x00000001,  
                INRANGE = 0x00000002,  
                INCONTACT = 0x00000004,  
                FIRSTBUTTON = 0x00000010,  
                SECONDBUTTON = 0x00000020,  
                THIRDBUTTON = 0x00000040,  
                FOURTHBUTTON = 0x00000080,  
                FIFTHBUTTON = 0x00000100,  
                PRIMARY = 0x00002000,  
                CONFIDENCE = 0x00004000,  
                CANCELED = 0x00008000,  
            }  
      
            internal enum TOUCH_FEEDBACK  
            {  
                DEFAULT = 0x1,  
                INDIRECT = 0x2,  
                NONE = 0x3  
            }  
      
            #endregion  
      
            //------------------------------------------------------------------  
      
      
            //------------------------------------------------------------------  
            #region ** misc structs  
      
      
            #region POINT  
      
            [StructLayout(LayoutKind.Sequential)]  
            internal struct POINT  
            {  
                public int X;  
                public int Y;  
      
                public POINT(int x, int y)  
                {  
                    X = x;  
                    Y = y;  
                }  
                public POINT(Point pt)  
                {  
                    X = pt.X;  
                    Y = pt.Y;  
                }  
                public Point ToPoint()  
                {  
                    return new Point(X, Y);  
                }  
                public void AssignTo(ref Point destination)  
                {  
                    destination.X = X;  
                    destination.Y = Y;  
                }  
                public void CopyFrom(Point source)  
                {  
                    X = source.X;  
                    Y = source.Y;  
                }  
                public void CopyFrom(POINT source)  
                {  
                    X = source.X;  
                    Y = source.Y;  
                }  
            }  
      
            #endregion  
      
            #region RECT  
      
            [StructLayout(LayoutKind.Sequential)]  
            internal struct RECT  
            {  
                public int Left;  
                public int Top;  
                public int Right;  
                public int Bottom;  
      
                public RECT(Rectangle source)  
                {  
                    Left = source.Left;  
                    Top = source.Top;  
                    Right = source.Right;  
                    Bottom = source.Bottom;  
                }  
                public RECT(int x, int y, int width, int height)  
                {  
                    Left = x;  
                    Top = y;  
                    Right = Left + width;  
                    Bottom = Top + height;  
                }  
                public int Width  
                {  
                    get { return Right - Left; }  
                }  
                public int Height  
                {  
                    get { return Bottom - Top; }  
                }  
                public Rectangle ToRectangle()  
                {  
                    return new Rectangle(Left, Top, Width, Height);  
                }  
                public void Inflate(int dx, int dy)  
                {  
                    Left -= dx;  
                    Top -= dy;  
                    Right += dx;  
                    Bottom += dy;  
                }  
                public void Deflate(int leftMargin, int topMargin, int rightMargin, int bottomMargin)  
                {  
                    Left += leftMargin;  
                    Top += topMargin;  
                    Right -= rightMargin;  
                    Bottom -= bottomMargin;  
                    if (Bottom < Top)  
                    {  
                        Bottom = Top;  
                    }  
                    if (Right < Left)  
                    {  
                        Right = Left;  
                    }  
                }  
                public void Offset(int dx, int dy)  
                {  
                    Left += dx;  
                    Top += dy;  
                    Right += dx;  
                    Bottom += dy;  
                }  
            }  
      
            #endregion  
      
            #endregion  
      
            //------------------------------------------------------------------  
            #region ** pointer structs  
      
            #region POINTER_INFO  
      
            [StructLayout(LayoutKind.Sequential)]  
            internal struct POINTER_INFO  
            {  
                public POINTER_INPUT_TYPE pointerType;  
                public int PointerID;  
                public int FrameID;  
                public POINTER_FLAGS PointerFlags;  
                public IntPtr SourceDevice;  
                public IntPtr WindowTarget;  
                [MarshalAs(UnmanagedType.Struct)]  
                public POINT PtPixelLocation;  
                [MarshalAs(UnmanagedType.Struct)]  
                public POINT PtPixelLocationRaw;  
                [MarshalAs(UnmanagedType.Struct)]  
                public POINT PtHimetricLocation;  
                [MarshalAs(UnmanagedType.Struct)]  
                public POINT PtHimetricLocationRaw;  
                public uint Time;  
                public uint HistoryCount;  
                public uint InputData;  
                public VIRTUAL_KEY_STATES KeyStates;  
                public long PerformanceCount;  
                public int ButtonChangeType;  
            }  
      
            #endregion  
      
            #region POINTER_TOUCH_INFO  
      
            [StructLayout(LayoutKind.Sequential)]  
            internal struct POINTER_TOUCH_INFO  
            {  
                [MarshalAs(UnmanagedType.Struct)]  
                public POINTER_INFO PointerInfo;  
                public TOUCH_FLAGS TouchFlags;  
                public TOUCH_MASK TouchMask;  
                [MarshalAs(UnmanagedType.Struct)]  
                public RECT ContactArea;  
                [MarshalAs(UnmanagedType.Struct)]  
                public RECT ContactAreaRaw;  
                public uint Orientation;  
                public uint Pressure;  
            }  
      
            #endregion  
      
            #region POINTER_PEN_INFO  
      
            [StructLayout(LayoutKind.Sequential)]  
            internal struct POINTER_PEN_INFO  
            {  
                [MarshalAs(UnmanagedType.Struct)]  
                public POINTER_INFO PointerInfo;  
                public PEN_FLAGS PenFlags;  
                public PEN_MASK PenMask;  
                public uint Pressure;  
                public uint Rotation;  
                public int TiltX;  
                public int TiltY;  
            }  
      
            #endregion  
      
            #endregion  
      
            //------------------------------------------------------------------  
            #region ** interaction context structs  
      
      
      
      
      
      
            #region INTERACTION_CONTEXT_OUTPUT  
      
      
            #endregion  
      
            #endregion  
      
      
            #region ** pointer methods  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool InitializeTouchInjection(int maxCount, TOUCH_FEEDBACK feedbackMode);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool InjectTouchInput(int count, [MarshalAs(UnmanagedType.LPArray), In] POINTER_TOUCH_INFO[] contacts);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerType(int pointerID, out POINTER_INPUT_TYPE pointerType);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerInfo(int pointerID, ref POINTER_INFO pointerInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerInfoHistory(int pointerID, ref int entriesCount, [MarshalAs(UnmanagedType.LPArray), In, Out] POINTER_INFO[] pointerInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerInfoHistory(int pointerID, ref int entriesCount, IntPtr pointerInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFrameInfo(int pointerID, ref int pointerCount, [MarshalAs(UnmanagedType.LPArray), In, Out] POINTER_INFO[] pointerInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFrameInfo(int pointerID, ref int pointerCount, IntPtr pointerInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFrameInfoHistory(int pointerID, ref int entriesCount, ref int pointerCount,  
                [MarshalAs(UnmanagedType.LPArray), In, Out] POINTER_INFO[] pointerInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFrameInfoHistory(int pointerID, ref int entriesCount, ref int pointerCount, IntPtr pointerInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerTouchInfo(int pointerID, ref POINTER_TOUCH_INFO touchInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFrameTouchInfo(int pointerID, ref int pointerCount, [MarshalAs(UnmanagedType.LPArray), In, Out] POINTER_TOUCH_INFO[] touchInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFrameTouchInfo(int pointerID, ref int pointerCount, IntPtr touchInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerPenInfo(int pointerID, ref POINTER_PEN_INFO penInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFramePenInfo(int pointerID, ref int pointerCount, [MarshalAs(UnmanagedType.LPArray), In, Out] POINTER_PEN_INFO[] penInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool GetPointerFramePenInfo(int pointerID, ref int pointerCount, IntPtr penInfo);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool SkipPointerFrameMessages(int pointerID);  
      
            [DllImport("user32.dll", SetLastError = true)]  
            internal static extern bool EnableMouseInPointer([MarshalAs(UnmanagedType.Bool), In] bool enable);  
      
            [DllImport("user32.dll")]  
            internal static extern bool IsMouseInPointerEnabled();  
      
            #endregion  
      
             
        }

If the answer is the right solution, please click "Accept Answer" and upvote it.If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer

Thanks, I got it to build, however, I got a new error in Program.cs :

Error 1 The type or namespace name 'Form1' could not be found (are you missing a using directive or an assembly reference?) C:\Users\Gennady G\Documents\Visual Studio 2013\Projects\WindowsFormsApplication-Test3\WindowsFormsApplication-Test3\Program.cs 24 17 WindowsFormsApplication-Test3

static void Main()
{
string strProcessName = Process.GetCurrentProcess().ProcessName;
Process[] Oprocesses = Process.GetProcessesByName(strProcessName);

        if (Oprocesses.Length == 1)
        {
            Form1 f1 = new Form1();
           // int height = System.Windows.Forms.Screen.PrimaryScreen.Bounds.Height;
          //  int width = System.Windows.Forms.Screen.PrimaryScreen.Bounds.Width;
          //  f1.Size = new Size(height   , width );

            Application.EnableVisualStyles();
            //Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(f1);
        }
        else { }
    }

this line: Form1 f1 = new Form1(); error

and another error:

Warning 3 Processing COM reference "WMPLib" from path "C:\WINDOWS\system32\wmp.dll". At least one of the arguments for 'IWMPGraphEventHandler.NotifyAcquireCredentials' cannot be marshaled by the runtime marshaler. Such arguments will therefore be passed as a pointer and may require unsafe code to manipulate. WindowsFormsApplication-Test3

also, I cannot find a file to open actual form design, meaning physical form where you bring items. And could not find how to

open explorer, meaning where I add events and items ? It is very confusing

Answer

Hi I have tested a Windows Form C# application on the tablet , everything is working, except there is a small bug, when I top with my finger anywhere else except buttons or

pictures, or any controls, but just on a form itself I get an exception ERROR:. I have attached a file, and would be happy to fix it.

Get back, thanks in advance.

************** Exception Text **************
System.NullReferenceException: Object reference not set to an instance of an object.
at WindowsFormsApplication_Test3.Form1.WndProc(Message& m) in c:\Users\Gennady G\Documents\Visual Studio 2013\Projects\WindowsFormsApplication-Test3\WindowsFormsApplication-Test3\Form1.cs:line 1426
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Windows Form C# mouse hover, mouse leave verses touchstart, touchend

3 answers

using ??? Or breaking down into several functions and files, so it it much clearer, so to figure out where is the error?