Develop Reference

How to use GetRawInputData from C#?

I'm trying to acquire keyboard input using GetRawInputData and C#. I don't seem to be able to actually read the RAWINPUTDATA fields, no matter what I use for the definition of the call.
I have tried this:
In response to the WM_INPUT message, I try this...
void ProcessRawInput(Message message)
{
uint dwSize = 0;
uint retval;
User32.RAWINPUT rawInput;
retval = User32.GetRawInputData(message.LParam, User32.RAWINPUT.RID_HEADER, out rawInput, ref dwSize, Marshal.SizeOf<User32.RAWINPUTHEADER>());
if (rawInput.header.dwType == (int)User32.RIM_TYPE.RIM_TYPEKEYBOARD)
{
}
}
It seems to read some data into the header structure, but nothing in the RAWINPUTDATA structure.
I tried something like:
if (rawInput.header.dwType == (int)User32.RIM_TYPE.RIM_TYPEKEYBOARD)
{
// set dwSize = Marshal.SizeOf<User32.RAWINPUT>()
retval = User32.GetRawInputData(message.LParam, User32.RAWINPUT.RID_INPUT, out rawInput, ref dwSize, Marshal.SizeOf<User32.RAWINPUTHEADER>());
}
But the only difference seems to be a huge value returned as retval.
I cannot seem to find a useable example (in C#).
My definitions and structures look like this:
[DllImport("User32.dll", SetLastError = true)]
internal static extern uint GetRawInputData(IntPtr hRawInput, uint uiCommand, out RAWINPUT pData, ref uint pcbSize, int cbSizeHeader);
[StructLayout(LayoutKind.Sequential)]
public struct RAWINPUT
{
public const int RID_INPUT = 0x10000003,
RID_HEADER = 0x10000005;
public RAWINPUTHEADER header;
public RAWINPUTDATA data;
}
[StructLayout(LayoutKind.Sequential)]
public struct RAWINPUTHEADER
{
public int dwType;
public int dwSize;
public IntPtr hDevice;
public IntPtr wParam;
}
[StructLayout(LayoutKind.Explicit)]
public struct RAWINPUTDATA
{
[FieldOffset(0)]
public RAWMOUSE Mouse;
[FieldOffset(0)]
public RAWKEYBOARD Keyboard;
[FieldOffset(0)]
public RAWHID HID;
}
[StructLayout(LayoutKind.Sequential)]
public struct RAWKEYBOARD
{
public ushort MakeCode;
public ushort Flags;
public ushort Reserved;
public ushort VKey;
public uint Message;
public ulong ExtraInformation;
}

C# SendInput() always returns 0 in Console Application

I have developed a simple Console application to poll an Xbox Controller using xinput. I would like to use the values obtained from one of the thumbsticks to move the mouse. I am able to get the x and y values from the thumbstick, but when I use those values to SendInput() (using the User32.dll), the mouse does not move and the return value is 0.
According to Microsoft, "If the function returns zero, the input was already blocked by another thread."
How do I find the other thread that is blocking it? It is just a simple Console Application (exe) started by Visual Studio that prints the x and y values to the screen and attempts to move the mouse.
long x = controller.x; // values from the controller
long y = controller.y; // these are checked and do contain numbers
INPUT mouseMoveInput = new INPUT();
mouseMoveInput.type = 0; // mouse
mouseMoveInput.mi.dx = x;
mouseMoveInput.mi.dy = y;
mouseMoveInput.mi.mouseData = 0;
mouseMoveInput.mi.dwFlags = MOUSEEVENTF_MOVE;
var result = SendInput(1, ref mouseMoveInput, Marshal.SizeOf(new INPUT());
// result always returns 0
Am I missing something? Should this work?
Here are declarations:
[StructLayout(LayoutKind.Explicit)]
public struct MOUSEINPUT
{
[FieldOffset(0)]
public long X;
[FieldOffset(8)]
public long Y;
[FieldOffset(16)]
public uint MouseData;
[FieldOffset(20)]
public uint Flags;
[FieldOffset(24)]
public uint Time;
[FieldOffset(28)]
public IntPtr ExtraInfo;
}
[StructLayout(LayoutKind.Sequential)]
internal struct KEYBOARDINPUT
{
public ushort Vk;
public ushort Scan;
public uint Flags;
public uint Time;
public IntPtr ExtraInfo;
}
[StructLayout(LayoutKind.Sequential)]
internal struct HARDWAREINPUT
{
public uint Msg;
public ushort ParamL;
public ushort ParamH;
}
[StructLayout(LayoutKind.Explicit)]
public struct INPUT
{
[FieldOffset(0)]
public uint type;
[FieldOffset(4)]
public MOUSEINPUT mi;
[FieldOffset(4)]
public KEYBOARDINPUT ki;
[FieldOffset(4)]
public HARDWAREINPUT hi;
}
UPDATE: using mouse-event does work, but this function is deprecated. Is there a problem with using it anyway since it works?
There is something odd I'm getting with the struct sizes:
Size of tagINPUT: 40
Size of mouseMoveInput: 40
Size of MOUSEINPUT: 32
Size of uint: 4
But if tagINPUT consists of MOUSEINPUT and uint then shouldn't it's size be 36?

The 2nd parameter of SendInput should be a pointer to an array, not a ref parameter, and especially not a ref directly to the struct.
I would also use explicit layout only for the struct that actually needs it, and let the rest be sequential. It's easier.
This code works for me:
const int INPUT_MOUSE = 0;
const int MOUSEEVENTF_MOVE = 0x0001;
[DllImport("user32.dll", SetLastError = true)]
private static extern uint SendInput(uint numberOfInputs, [MarshalAs(UnmanagedType.LPArray)] INPUT[] inputs, int sizeOfInputStructure);
void Main()
{
INPUT mouseMoveInput = new INPUT();
mouseMoveInput.type = INPUT_MOUSE;
mouseMoveInput.mi.dx = 10;
mouseMoveInput.mi.dy = 10;
mouseMoveInput.mi.mouseData = 0;
mouseMoveInput.mi.dwFlags = MOUSEEVENTF_MOVE;
var result = SendInput(1, new INPUT[] { mouseMoveInput}, Marshal.SizeOf(mouseMoveInput));
if(result == 0) {
throw new Win32Exception();
}
}
[StructLayout(LayoutKind.Sequential)]
public struct MOUSEINPUT
{
public int dx;
public int dy;
public uint mouseData;
public uint dwFlags;
public uint time;
public IntPtr dwExtraInfo;
}
[StructLayout(LayoutKind.Sequential)]
public struct KEYBDINPUT
{
public ushort wVk;
public ushort wScan;
public uint dwFlags;
public uint time;
public IntPtr dwExtraInfo;
}
[StructLayout(LayoutKind.Sequential)]
public struct HARDWAREINPUT
{
public uint Msg;
public ushort ParamL;
public ushort ParamH;
}
[StructLayout(LayoutKind.Explicit)]
public struct INPUT
{
[FieldOffset(0)]
public uint type;
[FieldOffset(4)]
public MOUSEINPUT mi;
[FieldOffset(4)]
public KEYBDINPUT ki;
[FieldOffset(4)]
public HARDWAREINPUT hi;
}

Windows SendInput (Keyboard) Not Working on Disconnect

I am running a c# application that makes use of the sendinputs method in windows to mimic keystrokes. It works fine when I am remoted into the instance, but as soon as I log out it throws an exception. Can anyone offer any thoughts on why this is happening, and how to avoid it?
UPDATE::
here is some sample code that can reproduce the issue.
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace ConsoleApplication6
{
class Program
{
class SendKey
{
[StructLayout(LayoutKind.Sequential)]
private struct MOUSEINPUT
{
public int dx;
public int dy;
public int mouseData;
public int dwFlags;
public int time;
public int dwExtraInfo;
};
[StructLayout(LayoutKind.Sequential)]
private struct KEYBDINPUT
{
public short wVk;
public short wScan;
public int dwFlags;
public int time;
public int dwExtraInfo;
};
[StructLayout(LayoutKind.Sequential)]
private struct HARDWAREINPUT
{
public int uMsg;
public short wParamL;
public short wParamH;
};
[StructLayout(LayoutKind.Explicit)]
private struct INPUT
{
[FieldOffset(0)]
public int type;
[FieldOffset(4)]
public MOUSEINPUT no;
[FieldOffset(4)]
public KEYBDINPUT ki;
[FieldOffset(4)]
public HARDWAREINPUT hi;
};
[DllImport("user32.dll")]
private extern static void SendInput(int nInputs, ref INPUT pInputs, int cbsize);
[DllImport("user32.dll", EntryPoint = "MapVirtualKeyA")]
private extern static int MapVirtualKey(int wCode, int wMapType);
private const int INPUT_KEYBOARD = 1;
private const int KEYEVENTF_KEYDOWN = 0x0;
private const int KEYEVENTF_KEYUP = 0x2;
private const int KEYEVENTF_EXTENDEDKEY = 0x1;
private void Send(Keys key, bool isEXTEND)
{
INPUT inp = new INPUT();
inp.type = INPUT_KEYBOARD;
inp.ki.wVk = (short)key;
inp.ki.wScan = (short)MapVirtualKey(inp.ki.wVk, 0);
inp.ki.dwFlags = ((isEXTEND) ? (KEYEVENTF_EXTENDEDKEY) : 0x0) | KEYEVENTF_KEYDOWN;
inp.ki.time = 0;
inp.ki.dwExtraInfo = 0;
SendInput(1, ref inp, Marshal.SizeOf(inp));
System.Threading.Thread.Sleep(100);
inp.ki.dwFlags = ((isEXTEND) ? (KEYEVENTF_EXTENDEDKEY) : 0x0) | KEYEVENTF_KEYUP;
SendInput(1, ref inp, Marshal.SizeOf(inp));
}
static void Main()
{
while(true)
{
System.Threading.Thread.Sleep(2000);
SendKey s = new SendKey();
s.Send(Keys.Z, false);
s.Send(Keys.Left, true);
}
}
}
}
}
if you build this and just run it on a free windows server ec2 instance with notepad in focus it will print zzzzzz continuously while you are remoted into the instance, however, as soon as you remote out of the instance, it will stop printing until you log back in.

C# method's type signature is not pinvoke compatible

I want to use API from Omron V4KU, the documentation described like this :
Original c# code :
const string DllLocation = #"..\..\Libs\Omron\OMCR.dll";
[DllImport(DllLocation)]
public static extern LPCOMCR OMCR_OpenDevice(string lpcszDevice, LPCOMCR_OPTION lpcOption);
public void Start()
{
var lpcOption = new LPCOMCR_OPTION();
var result = OMCR_OpenDevice(null, lpcOption); // error method's type signature is not pinvoke compatible
}
[StructLayout(LayoutKind.Sequential)]
public struct LPCOMCR
{
public string lpcszDevice;
public IntPtr hDevice;
public uint lpcDevice;
}
[StructLayout(LayoutKind.Sequential)]
public struct LPCOMCR_OPTION
{
public uint dwReserved0;
public uint dwReserved1;
public uint dwReserved2;
public uint dwReserved3;
}
if I missed or wrong in writing code?
sorry, my english is bad. thanks for help.

Start by defining the union structure correctly:
// OMCR_OPTION.COM
[StructLayout(LayoutKind.Sequential)]
public struct OmcrCom
{
public IntPtr Reserved0;
public uint BaudRate;
public uint Reserved1;
public uint Reserved2;
public uint Reserved3;
public IntPtr Reserved1;
public IntPtr Reserved2;
}
// OMCR_OPTION.USB
[StructLayout(LayoutKind.Sequential)]
public struct OmcrUsb
{
public uint Reserved0;
public uint Reserved1;
public uint Reserved2;
public uint Reserved3;
}
// OMCR_OPTION (union of COM and USB)
[StructLayout(LayoutKind.Explicit)]
public struct OmcrOptions
{
[FieldOffset(0)]
public OmcrCom Com;
[FieldOffset(0)]
public OmcrUsb Usb;
}
// OMCR
[StructLayout(LayoutKind.Sequential)]
public struct OmcrDevice
{
public string Device;
public IntPtr DeviceHandle;
public IntPtr DevicePointer;
}
[DllImport(dllName: DllLocation, EntryPoint = "OMCR_OpenDevice"]
public static extern IntPtr OmcrOpenDevice(string type, ref OmcrOptions options);
And then call the method, something like:
var options = new OmcrOptions();
options.Com.BaudRate = 115200; // or whatever you need to set
var type = "COM"; // is this USB/COM? not sure
OmcrDevice device;
var devicePtr = OmcrOpenDevice(type, ref options);
if (devicePtr == IntPtr.Zero)
device = (OmcrDevice)Marshal.PtrToStructure(devicePtr, typeof(OmcrDevice));

Well, for one, the documentation is asking you to pass LPCOMCR_OPTION as a pointer - you're passing it as a value. Using ref should help. There's another problem, though, and that's the return value - again, you're trying to interpret it as a value, while the docs say it's a pointer. However, this is a lot trickier than the first error - as far as I'm aware, your only options are using a C++/CLI interop library, or expecting IntPtr as a return value. In any case, you need to handle proper deallocation of the memory you get this way.

You need to do it like this:
[StructLayout(LayoutKind.Sequential)]
public struct OMCR
{
[MarshalAs(UnmanagedType.LPStr)]
public string lpcszDevice;
public IntPtr hDevice;
public IntPtr lpcDevice;
}
[StructLayout(LayoutKind.Sequential)]
public struct OMCR_OPTION
{
public uint dwReserved0;
public uint dwReserved1;
public uint dwReserved2;
public uint dwReserved3;
}
[DllImport(DllLocation, CallingConvention = CallingConvention.???,
SetLastError = true)]
public static extern IntPtr OMCR_OpenDevice(string lpcszDevice,
ref OMCR_OPTION lpcOption);
You need to replace CallingConvention.??? with the appropriate calling convention. We cannot tell from the question what that is. You will have to find out by reading the header file.
The return value is a pointer to OMCR. You need to hold on to this pointer and pass it to OMCR_CloseDevice when you are finished with it.
In order to obtain an OMCR value you would do the following:
OMCR_OPTION Option = new OMCR_OPTION(); // not sure how to initialize this
IntPtr DevicePtr = OMCR_OpenDevice(DeviceType, ref Option);
if (DevicePtr == IntPtr.Zero)
throw new Win32Exception();
OMCR Device = (OMCR)Marshal.PtrToStructure(DevicePtr, typeof(OMCR));

WPF Equivalent to SendInput?

Is there an equivalent to SendInput for WPF? I've looked into AutomationPeer classes but was not successfull.
I simply want to send a Keydown (the Enter Key). Simply raising the event (RaiseEvent) does not work in my scenario.
Here is what I have, which is working. I'd prefer to have a managed code alternative.
private void comboSelectionChanged(object sender, SelectionChangedEventArgs args)
{
((ComboBox)sender).Focus();
// send keydown
INPUT input = new INPUT();
input.type = INPUT_KEYBOARD;
input.union.keyboardInput.wVk = 0x0D;
input.union.keyboardInput.time = 0;
SendInput(1, ref input, Marshal.SizeOf(input));
}
[DllImport("user32.dll", SetLastError = true)]
private static extern int SendInput(int nInputs, ref INPUT mi, int cbSize);
[StructLayout(LayoutKind.Sequential)]
private struct INPUT
{
public int type;
public INPUTUNION union;
};
[StructLayout(LayoutKind.Explicit)]
private struct INPUTUNION
{
[FieldOffset(0)]
public MOUSEINPUT mouseInput;
[FieldOffset(0)]
public KEYBDINPUT keyboardInput;
};
[StructLayout(LayoutKind.Sequential)]
private struct MOUSEINPUT
{
public int dx;
public int dy;
public int mouseData;
public int dwFlags;
public int time;
public IntPtr dwExtraInfo;
};
[StructLayout(LayoutKind.Sequential)]
private struct KEYBDINPUT
{
public short wVk;
public short wScan;
public int dwFlags;
public int time;
public IntPtr dwExtraInfo;
};
private const int INPUT_MOUSE = 0;
private const int INPUT_KEYBOARD = 1;

You can emulate a keystroke like this:
public void SendKey(UIElement sourceElement, Key keyToSend)
{
KeyEventArgs args = new KeyEventArgs(InputManager.Current.PrimaryKeyboardDevice, PresentationSource.FromVisual(sourceElement), 0, keyToSend);
args.RoutedEvent = Keyboard.KeyDownEvent;
InputManager.Current.ProcessInput(args);
}
You could then call it like this:
SendKey(myComboBox, Key.Enter);
I suppose you can put this in a static class somewhere, or even make an extension method out of it. However, I would argue that in most cases there is a more elegant way to accomplish this.
I hope this helps.