I am trying to send simple key sequences (ctrl-p, shift-p) to the foreground app (which happens to be the Visual Studio editor unit test buffer). No matter what I try, I cannot get my test key sequences of control-p or shift-p to work properly. The 'p' appears in the buffer, but not with the control/shift part.
I have read easily a dozen code examples from SO and the net, read the documentation and tried variations too many to count. But without success. I'm on a standard Windows10x64 system, running the code as a unit test.
The code below sets both the virtual key and the scancode for the modifier keys, which is probably wrong in practice. I have tried both ways without success. I included the code to set both so that you could see the code I was using for both fields.
Does anyone know what I am doing wrong? Thank you.
** UPDATE ** My code was not failing. I was running it in a unit test within Visual Studio, which was blocking the modifier keys. When I ran the same code outside of a unit test (without all the debugging layers etc), the code ran fine.
Lesson: Don't try to debug your SendInput code modifier keys in unit tests!!
[DllImport("user32.dll", SetLastError = true)]
public static extern uint MapVirtualKey(uint uCode, uint uMapType);
[DllImport("user32.dll", SetLastError = true)]
public static extern uint SendInput(uint nInputs, KeyInput[] pInputs, int cbSize);
[Flags]
public enum KeyEventFlag
{
KeyDown = 0x0000,
ExtendedKey = 0x0001,
KeyUp = 0x0002,
Unicode = 0x0004,
Scancode = 0x0008
}
[Flags]
public enum InputType : int
{
Mouse = 0,
Keyboard = 1,
Hardware = 2
}
public struct KeyInput
{
public int type;
public WinSend.InputUnion u;
}
[StructLayout(LayoutKind.Explicit)]
public struct InputUnion
{
[FieldOffset(0)] public MouseInput mi;
[FieldOffset(0)] public KeyboardInput ki;
[FieldOffset(0)] public HardwareInput hi;
}
[StructLayout(LayoutKind.Sequential)]
public struct KeyboardInput
{
public ushort wVk;
public ushort wScan;
public uint dwFlags;
public uint time;
public IntPtr dwExtraInfo;
}
const uint MAPVK_VK_TO_VSC = 0x00;
const uint MAPVK_VSC_TO_VK = 0x01;
const uint MAPVK_VK_TO_CHAR = 0x02;
const uint MAPVK_VSC_TO_VK_EX = 0x03;
const uint MAPVK_VK_TO_VSC_EX = 0x04;
[TestMethod()]
public void SendControlKeyTest() {
DebugOn = true;
const uint VK_CONTROL = 0x11;
const uint VK_LCONTROL = 0xA2;
const uint VK_LSHIFT = 0xA0;
var keyList = new List<KeyInput>();
// wVk = A virtual-key code. The code must be a value in the range 1 to 254.
// If the dwFlags member specifies KEYEVENTF_UNICODE, wVk must be 0.
// wScan = A hardware scan code for the key. If dwFlags specifies KEYEVENTF_UNICODE,
// wScan specifies a Unicode char to send to the foreground application.
// the MapVirtualKey calls return successfully
var scanControl = MapVirtualKey((uint) VK_CONTROL, (uint) MAPVK_VK_TO_VSC);
if (scanControl == 0) Dprint("MapVirtualKey for VK_CONTROL failed.p");
var scanShift = MapVirtualKey((uint) VK_LSHIFT, (uint) MAPVK_VK_TO_VSC);
if (scanShift == 0) Dprint("MapVirtualKey for VK_LSHIFT failed.");
// this fails as is, fails with Flag.Unicode, and fails with no XXcode set
// this also fails with either VK_CONTROL or 0 in the wVk field
var vkdown = new KeyInput();
vkdown.type = (int) InputType.Keyboard;
vkdown.u.ki.wVk = (ushort) VK_CONTROL; // also fails with 0x0
vkdown.u.ki.dwFlags = (uint) (KeyEventFlag.Scancode | KeyEventFlag.KeyDown);
vkdown.u.ki.wScan = (ushort) scanControl;
keyList.Add(vkdown);
// this works - I see the 'p' when it runs
var keydown = new KeyInput();
keydown.type = (int) InputType.Keyboard;
keydown.u.ki.wVk = 0; // must be zero if Flag.Unicode is set
keydown.u.ki.dwFlags = (uint) (KeyEventFlag.Unicode | KeyEventFlag.KeyDown);
keydown.u.ki.wScan = (ushort) 'p';
keyList.Add(keydown);
// this works - I see the 'p' when it runs
var keyup = new KeyInput();
keyup.type = (int) InputType.Keyboard;
keyup.u.ki.wVk = 0; // must be zero if Flag.Unicode is set
keyup.u.ki.dwFlags = (uint) (KeyEventFlag.Unicode | KeyEventFlag.KeyUp);
keyup.u.ki.wScan = (ushort) 'p';
keyList.Add(keyup);
// this fails as is, fails with Flag.Unicode, and fails with no XXcode set
// this also fails with either VK_CONTROL or 0 in the wVk field
var vkup = new KeyInput();
vkup.type = (int) InputType.Keyboard;
vkup.u.ki.wVk = (ushort) VK_CONTROL; // also fails with 0x0
vkup.u.ki.dwFlags = (uint) (KeyEventFlag.Scancode| KeyEventFlag.KeyUp);
vkup.u.ki.wScan = (ushort) scanControl;
keyList.Add(vkup);
// SendInput returns 4, which means it sent 4 events successfully
var keycount = SendInput((uint) keyList.Count, keyList.ToArray(),
Marshal.SizeOf(typeof(KeyInput)));
Dprint($"Sent {keycount} keys to the system.");
// The Control-P should move my caret up one line, but it does not.
// Shift should create a capital P in the buffer, but it does not.
// All I see is a 'p' in the Visual studio buffer
}
Sorry for indirect answer but here's 100% working and tested solution for WPF application.
internal static class NativeMethods
{
[DllImport("user32.dll")]
public static extern uint SendInput(uint nInputs, INPUT[] pInputs, int cbSize);
[Flags]
public enum KeyboardFlags : uint
{
None = 0,
/// <summary>
/// KEYEVENTF_EXTENDEDKEY = 0x0001 (If specified, the scan code was preceded by a prefix byte that has the value 0xE0 (224).)
/// </summary>
ExtendedKey = 1,
/// <summary>
/// KEYEVENTF_KEYUP = 0x0002 (If specified, the key is being released. If not specified, the key is being pressed.)
/// </summary>
KeyUp = 2,
/// <summary>
/// KEYEVENTF_UNICODE = 0x0004 (If specified, wScan identifies the key and wVk is ignored.)
/// </summary>
Unicode = 4,
/// <summary>
/// KEYEVENTF_SCANCODE = 0x0008 (Windows 2000/XP: If specified, the system synthesizes a VK_PACKET keystroke. The wVk parameter must be zero. This flag can only be combined with the KEYEVENTF_KEYUP flag. For more information, see the Remarks section.)
/// </summary>
ScanCode = 8,
}
[Flags]
public enum MouseFlags : uint
{
/// <summary>
/// Specifies that movement occurred.
/// </summary>
Move = 0x0001,
/// <summary>
/// Specifies that the left button was pressed.
/// </summary>
LeftDown = 0x0002,
/// <summary>
/// Specifies that the left button was released.
/// </summary>
LeftUp = 0x0004,
/// <summary>
/// Specifies that the right button was pressed.
/// </summary>
RightDown = 0x0008,
/// <summary>
/// Specifies that the right button was released.
/// </summary>
RightUp = 0x0010,
/// <summary>
/// Specifies that the middle button was pressed.
/// </summary>
MiddleDown = 0x0020,
/// <summary>
/// Specifies that the middle button was released.
/// </summary>
MiddleUp = 0x0040,
/// <summary>
/// Windows 2000/XP: Specifies that an X button was pressed.
/// </summary>
XDown = 0x0080,
/// <summary>
/// Windows 2000/XP: Specifies that an X button was released.
/// </summary>
XUp = 0x0100,
/// <summary>
/// Windows NT/2000/XP: Specifies that the wheel was moved, if the mouse has a wheel. The amount of movement is specified in mouseData.
/// </summary>
VerticalWheel = 0x0800,
/// <summary>
/// Specifies that the wheel was moved horizontally, if the mouse has a wheel. The amount of movement is specified in mouseData. Windows 2000/XP: Not supported.
/// </summary>
HorizontalWheel = 0x1000,
/// <summary>
/// Windows 2000/XP: Maps coordinates to the entire desktop. Must be used with MOUSEEVENTF_ABSOLUTE.
/// </summary>
VirtualDesk = 0x4000,
/// <summary>
/// Specifies that the dx and dy members contain normalized absolute coordinates. If the flag is not set, dxand dy contain relative data (the change in position since the last reported position). This flag can be set, or not set, regardless of what kind of mouse or other pointing device, if any, is connected to the system. For further information about relative mouse motion, see the following Remarks section.
/// </summary>
Absolute = 0x8000,
}
[StructLayout(LayoutKind.Sequential)]
public struct KEYBDINPUT
{
public ushort virtualKey;
public ushort scanCode;
public KeyboardFlags flags;
public uint timeStamp;
public IntPtr extraInfo;
}
[StructLayout(LayoutKind.Sequential)]
public struct MOUSEINPUT
{
public int deltaX;
public int deltaY;
public uint mouseData;
public MouseFlags flags;
public uint time;
public IntPtr extraInfo;
}
[StructLayout(LayoutKind.Sequential)]
public struct HARDWAREINPUT
{
public uint message;
public ushort wParamL;
public ushort wParamH;
}
[StructLayout(LayoutKind.Explicit)]
public struct InputUnion
{
[FieldOffset(0)]
public MOUSEINPUT mouse;
[FieldOffset(0)]
public KEYBDINPUT keyboard;
[FieldOffset(0)]
public HARDWAREINPUT hardware;
}
public enum InputType : int
{
Mouse = 0,
Keyboard = 1,
Hardware = 2
}
public struct INPUT
{
public InputType type;
public InputUnion union;
}
}
KeyInterop.VirtualKeyFromKey here is standard method from .NET class. I guess that it can be replaced with WinAPI MapVirtualKey.
public static void ModifiedKeyStroke(Key key, ModifierKeys modifiers)
{
static NativeMethods.INPUT BuildINPUT(Key k, NativeMethods.KeyboardFlags flags) => new NativeMethods.INPUT
{
type = NativeMethods.InputType.Keyboard,
union = new NativeMethods.InputUnion { keyboard = new NativeMethods.KEYBDINPUT { virtualKey = (ushort)KeyInterop.VirtualKeyFromKey(k), scanCode = 0, flags = flags, timeStamp = 0, extraInfo = IntPtr.Zero } }
};
List<Key> keys = new List<Key>();
if (modifiers.HasFlag(ModifierKeys.Control)) keys.Add(Key.LeftCtrl);
if (modifiers.HasFlag(ModifierKeys.Alt)) keys.Add(Key.LeftAlt);
if (modifiers.HasFlag(ModifierKeys.Shift)) keys.Add(Key.LeftShift);
if (modifiers.HasFlag(ModifierKeys.Windows)) keys.Add(Key.LWin);
keys.Add(key);
NativeMethods.INPUT[] inputs = new NativeMethods.INPUT[keys.Count * 2];
uint i = 0;
foreach (Key k in keys) inputs[i++] = BuildINPUT(k, NativeMethods.KeyboardFlags.None);
keys.Reverse();
foreach (Key k in keys) inputs[i++] = BuildINPUT(k, NativeMethods.KeyboardFlags.KeyUp);
_ = NativeMethods.SendInput(i, inputs, Marshal.SizeOf(typeof(NativeMethods.INPUT)));
}
Usage
ModifiedKeyStroke(Key.C, ModifierKeys.Control); // sends Ctrl+C