c# - How to send a string to other application including Microsoft Word

Question

I was trying to accomplish this but did not get good results. I used GetForegroundWindow(), AttachThreadInput(uint,uint,bool) and GetFocus() functions to send the strings to another window. It works with Notepad, Wordpad and other applications, but not with Microsoft Word.

int foregroundWindowHandle = GetForegroundWindow();
uint remoteThreadId = GetWindowThreadProcessId(foregroundWindowHandle, 0);
uint currentThreadId = GetCurrentThreadId();
bool b = AttachThreadInput(remoteThreadId, currentThreadId, true);
int focused = GetFocus();
int d = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
b = AttachThreadInput(remoteThreadId, currentThreadId, false);
SendMessage(focused , WM_GETTEXT, builder.Capacity, builder);
clip = builder.ToString();

//Text operations...

SendMessage(focused, WM_SETTEXT, 0, builder);

That's the code I have, but it doesn't work with Word. I know that Word uses Custom Controls, but I think there should be another way to handle this.

For example: Windows Speech Recognition sends text to every application which has focus even if it is Word. I don't think they made the inputs manually.

I thought to use the SendInputs function but I don't know how to make that.

Answer 1

Check whether the following works; you just need to call SendString. This should work for any application that can receive text whose window is currently active.

All code except the first method is courtesy of pinvoke.net.

/// <summary>
/// Synthesizes keystrokes corresponding to the specified Unicode string,
/// sending them to the currently active window.
/// </summary>
/// <param name="s">The string to send.</param>
public static void SendString(string s)
{
    // Construct list of inputs in order to send them through a single SendInput call at the end.
    List<INPUT> inputs = new List<INPUT>();

    // Loop through each Unicode character in the string.
    foreach (char c in s)
    {
        // First send a key down, then a key up.
        foreach (bool keyUp in new bool[] { false, true })
        {
            // INPUT is a multi-purpose structure which can be used 
            // for synthesizing keystrokes, mouse motions, and button clicks.
            INPUT input = new INPUT
            {
                // Need a keyboard event.
                type = INPUT_KEYBOARD,
                u = new InputUnion
                {
                    // KEYBDINPUT will contain all the information for a single keyboard event
                    // (more precisely, for a single key-down or key-up).
                    ki = new KEYBDINPUT
                    {
                        // Virtual-key code must be 0 since we are sending Unicode characters.
                        wVk = 0,

                        // The Unicode character to be sent.
                        wScan = c,

                        // Indicate that we are sending a Unicode character.
                        // Also indicate key-up on the second iteration.
                        dwFlags = KEYEVENTF_UNICODE | (keyUp ? KEYEVENTF_KEYUP : 0),

                        dwExtraInfo = GetMessageExtraInfo(),
                    }
                }
            };

            // Add to the list (to be sent later).
            inputs.Add(input);
        }
    }

    // Send all inputs together using a Windows API call.
    SendInput((uint)inputs.Count, inputs.ToArray(), Marshal.SizeOf(typeof(INPUT)));
}

const int INPUT_MOUSE = 0;
const int INPUT_KEYBOARD = 1;
const int INPUT_HARDWARE = 2;
const uint KEYEVENTF_EXTENDEDKEY = 0x0001;
const uint KEYEVENTF_KEYUP = 0x0002;
const uint KEYEVENTF_UNICODE = 0x0004;
const uint KEYEVENTF_SCANCODE = 0x0008;
const uint XBUTTON1 = 0x0001;
const uint XBUTTON2 = 0x0002;
const uint MOUSEEVENTF_MOVE = 0x0001;
const uint MOUSEEVENTF_LEFTDOWN = 0x0002;
const uint MOUSEEVENTF_LEFTUP = 0x0004;
const uint MOUSEEVENTF_RIGHTDOWN = 0x0008;
const uint MOUSEEVENTF_RIGHTUP = 0x0010;
const uint MOUSEEVENTF_MIDDLEDOWN = 0x0020;
const uint MOUSEEVENTF_MIDDLEUP = 0x0040;
const uint MOUSEEVENTF_XDOWN = 0x0080;
const uint MOUSEEVENTF_XUP = 0x0100;
const uint MOUSEEVENTF_WHEEL = 0x0800;
const uint MOUSEEVENTF_VIRTUALDESK = 0x4000;
const uint MOUSEEVENTF_ABSOLUTE = 0x8000;

struct INPUT
{
    public int type;
    public InputUnion u;
}

[StructLayout(LayoutKind.Explicit)]
struct InputUnion
{
    [FieldOffset(0)]
    public MOUSEINPUT mi;
    [FieldOffset(0)]
    public KEYBDINPUT ki;
    [FieldOffset(0)]
    public HARDWAREINPUT hi;
}

[StructLayout(LayoutKind.Sequential)]
struct MOUSEINPUT
{
    public int dx;
    public int dy;
    public uint mouseData;
    public uint dwFlags;
    public uint time;
    public IntPtr dwExtraInfo;
}

[StructLayout(LayoutKind.Sequential)]
struct KEYBDINPUT
{
    /*Virtual Key code.  Must be from 1-254.  If the dwFlags member specifies KEYEVENTF_UNICODE, wVk must be 0.*/
    public ushort wVk;
    /*A hardware scan code for the key. If dwFlags specifies KEYEVENTF_UNICODE, wScan specifies a Unicode character which is to be sent to the foreground application.*/
    public ushort wScan;
    /*Specifies various aspects of a keystroke.  See the KEYEVENTF_ constants for more information.*/
    public uint dwFlags;
    /*The time stamp for the event, in milliseconds. If this parameter is zero, the system will provide its own time stamp.*/
    public uint time;
    /*An additional value associated with the keystroke. Use the GetMessageExtraInfo function to obtain this information.*/
    public IntPtr dwExtraInfo;
}

[StructLayout(LayoutKind.Sequential)]
struct HARDWAREINPUT
{
    public uint uMsg;
    public ushort wParamL;
    public ushort wParamH;
}

[DllImport("user32.dll")]
static extern IntPtr GetMessageExtraInfo();

[DllImport("user32.dll", SetLastError = true)]
static extern uint SendInput(uint nInputs, INPUT[] pInputs, int cbSize);