Using WM_SHOWWINDOW to Show a Window instead of ShowWindow()

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开发者_C百科 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.

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

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.

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);
        }
    }
}