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How can I remotely execute the ListBox1_DoubleClick event of a ListBox using WinApi/user32.dll or something similar?

I need to invoke the ListBox1_DoubleClick event from another application.
Look below how I think that should be the code:
using System.Runtime.InteropServices;
public class RemoteControl
{
[DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
private static extern IntPtr FindWindowByCaption(IntPtr zeroOnly, string lpWindowName);
public void SendClickLB(string sWinTitle, int iChildHandler)
{
var windowHWnd = FindWindowByCaption(IntPtr.Zero, windowTitle);
var childWindows = GetChildWindows(windowHWnd);
IntPtr hWnd = childWindows.ToArray()[index];
const int WM_LBUTTONDBLCLK = 0x0203;
SendMessage(hWnd, WM_LBUTTONDBLCLK, new IntPtr(0), new IntPtr(0));
}
}

I was able to trigger the ListBox's DbClick event remotely using user32.dll.
The steps I used to reach the expected result were as follows:
1 - First I had to get the X, Y coordinates through the Listbox handle using the ClientToScreen (hWnd, ref point) function;
2 - After I got through the coordinates obtained to move the mouse to the desired position and send the DoubleClick using the function mouse_event (MouseEventFlag dwFlags, int dx, int dy, int cButtons, int dwExtraInfo);
Many Thanks.

Position a small console window to the bottom left of the screen?

As the title says, I want to position it to the bottom left corner of the screen. Here's the code I have so far:
Console.WindowWidth = 50
Console.WindowHeight = 3
Console.BufferWidth = 50
Console.BufferHeight = 3
Console.BackgroundColor = ConsoleColor.Black
Console.ForegroundColor = ConsoleColor.DarkMagenta
Console.Title = "My Title"
Console.WriteLine("")
Console.Write(" Press any key to close this window ...")
Console.ReadKey()

Note: Despite their names, setting Console.WindowLeft and Console.WindowTop of the System.Console class does not change the window's position on screen.
Instead, they position the visible part of the window relative to the (potentially larger) window buffer - you cannot use type System.Console to change the position of console windows on the screen - you need to use the Windows API for that.
The following is code for a complete console application that positions its own window in the lower left corner of the screen, respecting the location of the taskbar.
Note:
It should work with multi-monitor setups - positioning the window on the specific monitor (display, screen) it is (mostly) being displayed on - but I haven't personally verified it.
Only Windows API functions are used via P/Invoke declarations, avoiding the need for referencing the WinForms assembly (System.Windows.Forms), which is not normally needed in console applications.
You'll see that a good portion of the code is devoted to P/Invoke signatures (declaration) for interfacing with the native Windows APIs; these were gratefully adapted from pinvoke.net
The actual code in the Main() method is short by comparison.
If you compile the code below from a console-application project in Visual Studio and run the resulting executable from a cmd.exe console window (Command Prompt), that console window should shift to the lower left corner of the (containing screen).
To verify the functionality while running from Visual Studio, place a breakpoint at the closing } and, when execution pauses, Alt-Tab to the console window to verify its position.
using System;
using System.Runtime.InteropServices; // To enable P/Invoke signatures.
public static class PositionConsoleWindowDemo
{
// P/Invoke declarations.
[DllImport("kernel32.dll")]
static extern IntPtr GetConsoleWindow();
[DllImport("user32.dll")]
static extern IntPtr MonitorFromWindow(IntPtr hwnd, uint dwFlags);
const int MONITOR_DEFAULTTOPRIMARY = 1;
[DllImport("user32.dll")]
static extern bool GetMonitorInfo(IntPtr hMonitor, ref MONITORINFO lpmi);
[StructLayout(LayoutKind.Sequential)]
struct MONITORINFO
{
public uint cbSize;
public RECT rcMonitor;
public RECT rcWork;
public uint dwFlags;
public static MONITORINFO Default
{
get { var inst= new MONITORINFO(); inst.cbSize = (uint)Marshal.SizeOf(inst); return inst; }
}
}
[StructLayout(LayoutKind.Sequential)]
struct RECT
{
public int Left, Top, Right, Bottom;
}
[StructLayout(LayoutKind.Sequential)]
struct POINT
{
public int x, y;
}
[DllImport("user32.dll", SetLastError = true)]
static extern bool GetWindowPlacement(IntPtr hWnd, ref WINDOWPLACEMENT lpwndpl);
[DllImport("user32.dll", SetLastError = true)]
static extern bool SetWindowPlacement(IntPtr hWnd, [In] ref WINDOWPLACEMENT lpwndpl);
const uint SW_RESTORE= 9;
[StructLayout(LayoutKind.Sequential)]
struct WINDOWPLACEMENT
{
public uint Length;
public uint Flags;
public uint ShowCmd;
public POINT MinPosition;
public POINT MaxPosition;
public RECT NormalPosition;
public static WINDOWPLACEMENT Default
{
get
{
var instance = new WINDOWPLACEMENT();
instance.Length = (uint) Marshal.SizeOf(instance);
return instance;
}
}
}
public static void Main()
{
// Get this console window's hWnd (window handle).
IntPtr hWnd = GetConsoleWindow();
// Get information about the monitor (display) that the window is (mostly) displayed on.
// The .rcWork field contains the monitor's work area, i.e., the usable space excluding
// the taskbar (and "application desktop toolbars" - see https://msdn.microsoft.com/en-us/library/windows/desktop/ms724947(v=vs.85).aspx)
var mi = MONITORINFO.Default;
GetMonitorInfo(MonitorFromWindow(hWnd, MONITOR_DEFAULTTOPRIMARY), ref mi);
// Get information about this window's current placement.
var wp = WINDOWPLACEMENT.Default;
GetWindowPlacement(hWnd, ref wp);
// Calculate the window's new position: lower left corner.
// !! Inexplicably, on W10, work-area coordinates (0,0) appear to be (7,7) pixels
// !! away from the true edge of the screen / taskbar.
int fudgeOffset = 7;
wp.NormalPosition = new RECT() {
Left = -fudgeOffset,
Top = mi.rcWork.Bottom - (wp.NormalPosition.Bottom - wp.NormalPosition.Top),
Right = (wp.NormalPosition.Right - wp.NormalPosition.Left),
Bottom = fudgeOffset + mi.rcWork.Bottom
};
// Place the window at the new position.
SetWindowPlacement(hWnd, ref wp);
}
}

You can use Console.WindowTop and Console.WindowWidth of the System.Console class to set the location of the console window.
Here is an example on MSDN
The BufferHeight and BufferWidth property gets/sets the number of rows and columns to be displayed.
WindowHeight and WindowWidth properties must always be less than BufferHeight and BufferWidth respectively.
WindowLeft must be less than BufferWidth - WindowWidth and WindowTop must be less than BufferHeight - WindowHeight.
WindowLeft and WindowTop are relative to the buffer.
To move the actual console window, this article has a good example.
I have used some of your code and code from the CodeProject sample. You can set window location and size both in a single function. No need to set Console.WindowHeight and Console.WindowWidth again. This is how my class looks:
class Program
{
const int SWP_NOZORDER = 0x4;
const int SWP_NOACTIVATE = 0x10;
[DllImport("kernel32")]
static extern IntPtr GetConsoleWindow();
[DllImport("user32")]
static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter,
int x, int y, int cx, int cy, int flags);
static void Main(string[] args)
{
Console.WindowWidth = 50;
Console.WindowHeight = 3;
Console.BufferWidth = 50;
Console.BufferHeight = 3;
Console.BackgroundColor = ConsoleColor.Black;
Console.ForegroundColor = ConsoleColor.DarkMagenta;
var screen = System.Windows.Forms.Screen.PrimaryScreen.Bounds;
var width = screen.Width;
var height = screen.Height;
SetWindowPosition(100, height - 300, 500, 100);
Console.Title = "My Title";
Console.WriteLine("");
Console.Write(" Press any key to close this window ...");
Console.ReadKey();
}
/// <summary>
/// Sets the console window location and size in pixels
/// </summary>
public static void SetWindowPosition(int x, int y, int width, int height)
{
SetWindowPos(Handle, IntPtr.Zero, x, y, width, height, SWP_NOZORDER | SWP_NOACTIVATE);
}
public static IntPtr Handle
{
get
{
//Initialize();
return GetConsoleWindow();
}
}
}

Run any console application
Click RMB on headline.
Choose properties option.
choose Position tab.
Uncheck box "Automatic choice"
Set console position as you want.

How do I set the focus to the Desktop from within my C# application

Winforms App. .Net 3.5.
I need to set the focus from my C# application to the user's desktop (almost like simulating a mouse click on the desktop).
Can someone please show me how to do this with C#? I just want to set focus on the desktop so the focus is no longer on my application but I want to do this from within my application.
Edit: An answer below works by setting the focus to the desktop, but it minimizes all the open windows on the user's desktop.
Is there a way I can maybe set the focus to the next open window on the desktop instead? I just want to get the focus off of my application (without minimizing my application or hiding it). I just want to move focus to somewhere else. Maybe the desktop was not the best choice if it will minimize all the user's open windows/applications.

This should do it for you.
using System;
using System.Runtime.InteropServices;
namespace ConsoleApplication1 {
class Program {
[DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll", EntryPoint = "SendMessage", SetLastError = true)]
static extern IntPtr SendMessage(IntPtr hWnd, Int32 Msg, IntPtr wParam, IntPtr lParam);
const int WM_COMMAND = 0x111;
const int MIN_ALL = 419;
const int MIN_ALL_UNDO = 416;
static void Main(string[] args) {
IntPtr lHwnd = FindWindow("Shell_TrayWnd", null);
SendMessage(lHwnd, WM_COMMAND, (IntPtr)MIN_ALL, IntPtr.Zero);
System.Threading.Thread.Sleep(2000);
SendMessage(lHwnd, WM_COMMAND, (IntPtr)MIN_ALL_UNDO, IntPtr.Zero);
}
}
}
Get Next Window
I don't have a code example ready for these two but I'm going to give you the links to both. The first think you need to do is call GetWindow. After doing that you'll want to call SwitchToThisWindow passing in the pointer you received from GetWindow.

You can add this COM object in your project:
Microsoft Shell Controls And Automation
And then just call:
Shell32.ShellClass shell = new Shell32.ShellClass();
shell.MinimizeAll();
This will minimize all the windows and then focus the desktop. Otherwise, if you have your window non-full screen then you can simulate the mouse click using:
//This is a replacement for Cursor.Position in WinForms
[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern bool SetCursorPos(int x, int y);
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern void mouse_event(int dwFlags, int dx, int dy, int cButtons, int dwExtraInfo);
public const int MOUSEEVENTF_LEFTDOWN = 0x02;
public const int MOUSEEVENTF_LEFTUP = 0x04;
//This simulates a left mouse click
public static void LeftMouseClick(int xpos, int ypos)
{
SetCursorPos(xpos, ypos);
mouse_event(MOUSEEVENTF_LEFTDOWN, xpos, ypos, 0, 0);
mouse_event(MOUSEEVENTF_LEFTUP, xpos, ypos, 0, 0);
}
You can calculate coordinates by looking at your window startup location plus height/width and select a available space (that will be the desktop indeed).

How do I prevent the original form from losing focus when I show another form?

I am having a problem where my main form loses focus when opening a new form. I know I can revert the focus back by using mainForm.focus(), but how do I handle things if I want the main form to never give up its focus when new window is opened?

You can accomplish this by overriding the property ShowWithoutActivation in order for it to return true in the forms that you want to show without stealing focus from the form that shown it, in your case that would be your main form.

Cody Gray answered this, I'm just expanding it by directly pasting the code. Someone with edit rights can copy it over there and delete this for all I care ;)
pinvoke.net's ShowWindow method.:
private const int SW_SHOWNOACTIVATE = 4;
private const int HWND_TOPMOST = -1;
private const uint SWP_NOACTIVATE = 0x0010;
[DllImport("user32.dll", EntryPoint = "SetWindowPos")]
static extern bool SetWindowPos(
int hWnd, // window handle
int hWndInsertAfter, // placement-order handle
int X, // horizontal position
int Y, // vertical position
int cx, // width
int cy, // height
uint uFlags); // window positioning flags
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
static void ShowInactiveTopmost(Form frm)
{
ShowWindow(frm.Handle, SW_SHOWNOACTIVATE);
SetWindowPos(frm.Handle.ToInt32(), HWND_TOPMOST,frm.Left, frm.Top, frm.Width, frm.Height,SWP_NOACTIVATE);
frm.TopMost = false;
}

Hiding window from taskbar in C# with WinAPI

Believe me, I have Googled it and expected it to be a fairly easy find - turns out it isn't.
I have my window handle, but no form. How do I do it?
Thanks!

Declare these:
[DllImport("user32.dll", SetLastError = true)]
static extern int GetWindowLong(IntPtr hWnd, int nIndex);
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
private const int GWL_EX_STYLE = -20;
private const int WS_EX_APPWINDOW = 0x00040000, WS_EX_TOOLWINDOW = 0x00000080;
And then use this before the form is shown:
SetWindowLong(handle, GWL_EX_STYLE, (GetWindowLong(handle, GWL_EX_STYLE) | WS_EX_TOOLWINDOW) & ~WS_EX_APPWINDOW);
(change handle to whatever your window handle is stored in)

Set Form's ShowInTaskbar property to false.