Using User32.dll SendMessage To Send Keys With ALT Modifier [duplicate]

Answer 1

Another solution. It doesn't appear you are passing anything for the lparam of the WM_SYSKEYDOWN. Yet the docs, clearly suggest that bit 29 of the lparam needs to be set to indicate the ALT key was pressed.

ushort action = (ushort)WM_SYSKEYDOWN;
ushort key = (ushort)System.Windows.Forms.Keys.F1;
uint lparam = (0x01 << 28);
SendMessage(hWnd, action, key, lparam);

Answer 2

I don't think SendMessage and WM_SYSKEYDOWN is what you want to use. Instead, use the SendInput function. If I recall, you'll likely pass four inputs for every keystroke you want to simulate. One for the "down" event of the alt key. Another down event for the corresponding key. Then two up events for each.

It's been a while since I've had to write code like this, but I believe the docs suggest that VK_MENU is the code for the "alt" key.