How to prevent raw mouse clicks outside an application using c#

Question

I am attempting to control two "mice". The primary mouse (mice) are used for controlling the cursor for normal UI control (which I don't want to intercept) and a secondary "mouse" which should only be used as input into the application I am writing and ignored otherwise.

I am successfully capturing the mouse messages and filtering as desired. I can also successfully capture the mouse inputs,even when my app is not in focus (as desired).

The only remaining issue is that I can't seem to keep the mouse from interacting with other applications. So I can essentially spy on the mouse, but not fully consume the message.

I "believe" I am preventing the "base.WndProc(ref message)" from getting called when I am processing the filtered mouse messages, but the system still seems to be getting the mouse clicks.

Is C# (Visual Studio Express 2010) able to do this?

Thank you for any assistance you might be able to give.

Answer 1

Raw input might be what you're looking for. Here is an MSDN discussion with a similar question which has link to a codeproject article on handling mutliple keyboards in C#.

Answer 2

You can use global mouse hook. I don't remember where I've found it, but here is the sample

Answer 3

As others have stated this is at the very least troublesome in dot net. I would highly recommend you switch over to C++ / Win32 to achieve this. I think you will save yourself a lot of headache in the long run.

Answer 4

I don't think it is possible to prevent a mouse click via C# .Net. However, you might be able to lock the mouse pointer in one position via ClipCursor. The below link may help you with that.

If you essentially want to prevent one mouse from being used why not just disable the mouse like you could if you went to device manager and clicked "disable". This can be done programmatically as solved here.

Here is the code copied from the link above:

public static class DisableHardware
{
    const uint DIF_PROPERTYCHANGE = 0x12;
    const uint DICS_ENABLE = 1;
    const uint DICS_DISABLE = 2;  // disable device
    const uint DICS_FLAG_GLOBAL = 1; // not profile-specific
    const uint DIGCF_ALLCLASSES = 4;
    const uint DIGCF_PRESENT = 2;
    const uint ERROR_INVALID_DATA = 13;
    const uint ERROR_NO_MORE_ITEMS = 259;
    const uint ERROR_ELEMENT_NOT_FOUND = 1168;

    static DEVPROPKEY DEVPKEY_Device_DeviceDesc;
    static DEVPROPKEY DEVPKEY_Device_HardwareIds;

    [StructLayout(LayoutKind.Sequential)]
    struct SP_CLASSINSTALL_HEADER
    {
        public UInt32 cbSize;
        public UInt32 InstallFunction;
    }

    [StructLayout(LayoutKind.Sequential)]
    struct SP_PROPCHANGE_PARAMS
    {
        public SP_CLASSINSTALL_HEADER ClassInstallHeader;
        public UInt32 StateChange;
        public UInt32 Scope;
        public UInt32 HwProfile;
    }

    [StructLayout(LayoutKind.Sequential)]
    struct SP_DEVINFO_DATA
    {
        public UInt32 cbSize;
        public Guid classGuid;
        public UInt32 devInst;
        public IntPtr reserved;     // CHANGE #1 - was UInt32
    }

    [StructLayout(LayoutKind.Sequential)]
    struct DEVPROPKEY
    {
        public Guid fmtid;
        public UInt32 pid;
    }

    [DllImport("setupapi.dll", SetLastError = true)]
    static extern IntPtr SetupDiGetClassDevsW(
        [In] ref Guid ClassGuid,
        [MarshalAs(UnmanagedType.LPWStr)]
string Enumerator,
        IntPtr parent,
        UInt32 flags);

    [DllImport("setupapi.dll", SetLastError = true)]
    static extern bool SetupDiDestroyDeviceInfoList(IntPtr handle);

    [DllImport("setupapi.dll", SetLastError = true)]
    static extern bool SetupDiEnumDeviceInfo(IntPtr deviceInfoSet,
        UInt32 memberIndex,
        [Out] out SP_DEVINFO_DATA deviceInfoData);

    [DllImport("setupapi.dll", SetLastError = true)]
    static extern bool SetupDiSetClassInstallParams(
        IntPtr deviceInfoSet,
        [In] ref SP_DEVINFO_DATA deviceInfoData,
        [In] ref SP_PROPCHANGE_PARAMS classInstallParams,
        UInt32 ClassInstallParamsSize);

    [DllImport("setupapi.dll", SetLastError = true)]
    static extern bool SetupDiChangeState(
        IntPtr deviceInfoSet,
        [In] ref SP_DEVINFO_DATA deviceInfoData);

    [DllImport("setupapi.dll", SetLastError = true)]
    static extern bool SetupDiGetDevicePropertyW(
            IntPtr deviceInfoSet,
            [In] ref SP_DEVINFO_DATA DeviceInfoData,
            [In] ref DEVPROPKEY propertyKey,
            [Out] out UInt32 propertyType,
            IntPtr propertyBuffer,
            UInt32 propertyBufferSize,
            out UInt32 requiredSize,
            UInt32 flags);

    [DllImport("setupapi.dll", SetLastError = true)]
    static extern bool SetupDiGetDeviceRegistryPropertyW(
      IntPtr DeviceInfoSet,
      [In] ref SP_DEVINFO_DATA  DeviceInfoData,
      UInt32 Property,
      [Out] out UInt32  PropertyRegDataType,
      IntPtr PropertyBuffer,
      UInt32 PropertyBufferSize,
      [In,Out] ref UInt32 RequiredSize
    );

    static DisableHardware()
    {
        DisableHardware.DEVPKEY_Device_DeviceDesc = new DEVPROPKEY();
        DEVPKEY_Device_DeviceDesc.fmtid = new Guid(
                0xa45c254e, 0xdf1c, 0x4efd, 0x80, 0x20, 0x67,
                0xd1, 0x46, 0xa8, 0x50, 0xe0);
        DEVPKEY_Device_DeviceDesc.pid = 2;

        DEVPKEY_Device_HardwareIds = new DEVPROPKEY();
        DEVPKEY_Device_HardwareIds.fmtid = new Guid(
            0xa45c254e, 0xdf1c, 0x4efd, 0x80, 0x20, 0x67,
            0xd1, 0x46, 0xa8, 0x50, 0xe0);
        DEVPKEY_Device_HardwareIds.pid = 3;
    }




    public static void DisableDevice(Func<string, bool> filter, bool disable = true)
    {
        IntPtr info = IntPtr.Zero;
        Guid NullGuid = Guid.Empty;
        try
        {
            info = SetupDiGetClassDevsW(
                ref NullGuid,
                null,
                IntPtr.Zero,
                DIGCF_ALLCLASSES);
            CheckError("SetupDiGetClassDevs");

            SP_DEVINFO_DATA devdata = new SP_DEVINFO_DATA();
            devdata.cbSize = (UInt32)Marshal.SizeOf(devdata);

            // Get first device matching device criterion.
            for (uint i = 0; ; i++)
            {
                SetupDiEnumDeviceInfo(info,
                    i,
                    out devdata);
                // if no items match filter, throw
                if (Marshal.GetLastWin32Error() == ERROR_NO_MORE_ITEMS)
                    CheckError("No device found matching filter.", 0xcffff);
                CheckError("SetupDiEnumDeviceInfo");

                string devicepath = GetStringPropertyForDevice(info,
                                           devdata, 1); // SPDRP_HARDWAREID

                // Uncomment to print name/path
                //Console.WriteLine(GetStringPropertyForDevice(info,
                //                         devdata, DEVPKEY_Device_DeviceDesc));
                //Console.WriteLine("   {0}", devicepath);
                if (devicepath != null && filter(devicepath)) break;

            }

            SP_CLASSINSTALL_HEADER header = new SP_CLASSINSTALL_HEADER();
            header.cbSize = (UInt32)Marshal.SizeOf(header);
            header.InstallFunction = DIF_PROPERTYCHANGE;

            SP_PROPCHANGE_PARAMS propchangeparams = new SP_PROPCHANGE_PARAMS();
            propchangeparams.ClassInstallHeader = header;
            propchangeparams.StateChange = disable ? DICS_DISABLE : DICS_ENABLE;
            propchangeparams.Scope = DICS_FLAG_GLOBAL;
            propchangeparams.HwProfile = 0;

            SetupDiSetClassInstallParams(info,
                ref devdata,
                ref propchangeparams,
                (UInt32)Marshal.SizeOf(propchangeparams));
            CheckError("SetupDiSetClassInstallParams");

            SetupDiChangeState(
                info,
                ref devdata);
            CheckError("SetupDiChangeState");
        }
        finally
        {
            if (info != IntPtr.Zero)
                SetupDiDestroyDeviceInfoList(info);
        }
    }
    private static void CheckError(string message, int lasterror = -1)
    {

        int code = lasterror == -1 ? Marshal.GetLastWin32Error() : lasterror;
        if (code != 0)
            throw new ApplicationException(
                String.Format("Error disabling hardware device (Code {0}): {1}",
                    code, message));
    }

    private static string GetStringPropertyForDevice(IntPtr info, SP_DEVINFO_DATA devdata,
        uint propId)
    {
        uint proptype, outsize;
        IntPtr buffer = IntPtr.Zero;
        try
        {
            uint buflen = 512;
            buffer = Marshal.AllocHGlobal((int)buflen);
            outsize=0;
            // CHANGE #2 - Use this instead of SetupDiGetDeviceProperty 
            SetupDiGetDeviceRegistryPropertyW(
                info,
                ref devdata,
                propId,
                out proptype,
                buffer,
                buflen,
                ref outsize);
            byte[] lbuffer = new byte[outsize];
            Marshal.Copy(buffer, lbuffer, 0, (int)outsize);
            int errcode = Marshal.GetLastWin32Error();
            if (errcode == ERROR_INVALID_DATA) return null;
            CheckError("SetupDiGetDeviceProperty", errcode);
            return Encoding.Unicode.GetString(lbuffer);
        }
        finally
        {
            if (buffer != IntPtr.Zero)
                Marshal.FreeHGlobal(buffer);
        }
    }

}

http://msdn.microsoft.com/en-us/library/windows/desktop/ms648383%28v=vs.85%29.aspx http://www.pinvoke.net/default.aspx/user32/ClipCursor.html