Using WM_SHOWWINDOW to Show a Window instead of ShowWindow() - windows

Question

I’m trying to use the SendMessage function of a hotkey utility (or NirCMD, etc.) to get a hidden window to pop up. I can for example get windows to close by sending 0x0010 (WM_CLOSE), but when I try sending 0x0018 (WM_SHOWWINDOW) with a wParam of 1 and an lParam of 0, nothing happens.
I’ve looked around, and the few places where someone complained that WM_SHOWWINDOW did not work, they happily took the suggestion to use ShowWindow() instead.
However I don’t have ShowWindow() available; I can only send Windows messages. But ShowWindow() is not magic, surely it works by SendMessage-ing a WM_SHOWWINDOW or something under the covers.
How can I get a window to display itself by sending it a message?
Thanks.

Answer 1

Try these two messages:
SendMessage(h,WM_SYSCOMMAND,SC_MINIMIZE,0);
SendMessage(h,WM_SYSCOMMAND,SC_RESTORE,0);
Or if using 3rd party apps is ok, try cmdow

Answer 2

WM_SHOWWINDOW is a notification, not a command. From MSDN:
The WM_SHOWWINDOW message is sent to a window when the window is about to be hidden or shown.
I don't believe there is any message that you can use to make a window show itself. Actually, the very idea seems a little strange to me. The window manager is the system component responsible for showing and hiding windows. To show a window, you must use one of the window manager APIs.

Answer 3

I think there is no way to achieve that with SendMessage (WM_SYSCOMMAND didn't work for me). I tried actually in C#. You click the button, the window will be minimized via ShowWindow() and then you can see what messages are sent:
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public class Form1: Form
{
[DllImport("user32.dll", SetLastError = true)]
public static extern bool ShowWindow(IntPtr window, int showCommand);
private const int SW_MINIMIZE = 6;
private bool print = false;
public Form1()
{
Button button = new Button();
button.Click += onButtonsClick;
Controls.Add(button);
}
private void onButtonsClick(object sender, EventArgs e)
{
print = true;
ShowWindow(Handle, SW_MINIMIZE);
print = false;
}
protected override void WndProc(ref Message m)
{
if (print)
Console.WriteLine(m.Msg.ToString() + "\t0x" + m.Msg.ToString("x4") + "\t" + m.WParam + "\t" + m.LParam);
base.WndProc(ref m);
}
}
}