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MonitorFromWindow(DefaultToNearest) doesn't work during drag

I'm using the Windows API method MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST) as part of some overridden maximize functionality in my WPF application. One issue we've had with it is that the "nearest" window does not updating during drag operations (triggered by DragMove on the Window instance).
Suppose you drag the window between two screens of differing resolution and trigger the Aero Snap functionality on the second screen. This triggers a query on the window size (message WM_GETMINMAXINFO). Using MonitorFromWindow in this scenario returns the wrong screen. It's as if the data used by MONITOR_DEFAULTTONEAREST is not updated until the drag operation completes, and that doesn't complete until the resize function triggered by the Aero Snap completes. Is there some way to flush the current window position before answering the WM_GETMINMAXINFO query?

Since snapping is based on the mouse position, a solution to the problem would be to use GetCursorPos to get the current mouse position. Then pass that point to MonitorFromPoint to obtain the handle for the monitor that currently contains the mouse pointer.
A simple example:
[DllImport("User32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetCursorPos(ref Point lpPoint);
public const int MONITOR_DEFAULTTONEAREST = 2;
[DllImport("User32.dll")]
public static extern IntPtr MonitorFromPoint(Point pt, UInt32 dwFlags);
public IntPtr GetCurrentMonitor()
{
Point p = new Point(0,0);
if (!GetCursorPos(ref p))
{
// Decide what to do here.
}
IntPtr hMonitor = MonitorFromPoint(p, MONITOR_DEFAULTTONEAREST);
// validate hMonitor
return hMonitor;
}

C# Ghost Outline Form Resize

Normally, my C# app shows the full window contents dynamically resizing while the form itself is resizing.
I clearly remember some apps doing this very nice effect where rather than doing this, it would just show a ghostly border during resize and THEN redraw the window.
How do I get this lovely effect in my forms? I can't find any thing on Google that appears to pertain to this.

PInvoke SystemParametersInfo to change it, but it changes for all windows.
Here is a references for all commands: MSDN SystemParametersInfo
[System.Runtime.InteropServices.DllImport("user32.dll")]
private static extern int SystemParametersInfo(int uAction, int uParam, int lpvParam, int fuWinIni);
[STAThread]
static void Main() {
int SPI_SETDRAGFULLWINDOWS = 0x0025;
SystemParametersInfo(SPI_SETDRAGFULLWINDOWS,0,0,2);
Application.Run(new Form());
}

Snap WinForm to program

Is it possible to do the following with WinForms/C#?
Dynamically detect window size and position of a running program (for example Notepad.exe)?
Snap WinForm to specific position within Notepad.exe?
Minimize and maximize WinForm window with other process (so when Notepad is minimize, so is WinForm window)?
See for example (black shape would be WinForm window):
Essentially I need to create a toolbar for a program, and the toolbar should "snap" to that program in the same place regardless of position or size of window.

First find the handle of the notepad window:
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
Just pass null for the first parameter and the caption ("Notepad"?) of the window as the second parameter.
An alternative would be to enumerate all windows and select the best match based on the caption:
using System.Runtime.InteropServices;
public delegate bool CallBackPtr(int hwnd, int lParam);
private CallBackPtr callBackPtr;
public class EnumReport
{
[DllImport("user32.dll")]
private static extern int EnumWindows(CallBackPtr callPtr, int lPar);
public static bool Report(int hwnd, int lParam)
{
Console.WriteLine("Window handle is "+hwnd);
return true;
}
}
static void Main()
{
// note in other situations, it is important to keep
// callBackPtr as a member variable so it doesnt GC while you're calling EnumWindows
callBackPtr = new CallBackPtr(EnumReport.Report);
EnumReport.EnumWindows(callBackPtr, 0);
}
Then attach a WndProc to it:
HwndSource src = HwndSource.FromHwnd(windowHandle);
src.AddHook(new HwndSourceHook(WndProc));
In the WndProc respond to the resizing and moving of the window.
I am not sure about setting the toolbar as a child of the notepad window; that might have unexpected effects when Notepad tries to manage it and order its z-depth.
At the same time I doubt this to be a good thing; the user will be able to type 'below' the overlay and lose his cursor/text.

Find Notepad's window (FindWindow).
Create your window without borders.
Set your window as a child of Notepad's window (SetParent).
Your window will be anchored to the top left corner of Notepad's window. Minimizing will be handled automatically, but you'll need to resize your window when Notepad's window is resized (or maximized). You may also want to move Notepad's edit control.
WinForms can be used, but you'll need some interop calls.
I have to warn that this is not a very good idea. Your controls may conflict with controls inside host process's window, host process may rearrange controls the way you don't like, draw over your controls. In general, be ready to fight with numerous issues without a good clean solution, and to accept that there may be glitches when resizing etc.
See also:
Attach form window to another window in C#.

How to add an extra button to the window's title bar?

I've seen that some apps (maybe not .NET apps) that have an extra button on the left from the minimize button on the form's title bar? How can I achieve this in C#?

UPDATE: Added a solution that will work with Aero enabled for Windows Vista and Windows 7
***Non-Aero Solution***
The non-client area of a window interaction is managed by a series of non-client specfic messages. For example WM_NCPAINT message is sent to the window procedure to paint the non-client area.
I have never done this from .NET, but I suspect you can overide the WndProc and handle the WM_NC* messages to achieve what you want.
Update: Since I never tried this from .NET I got a few minutes and thought I would give it a quick try.
Trying this on Windows 7, I found that I needed to disable the Themes for the Window if I wanted to OS to do the base rendering of the non-client area. So here is a short test. I used GetWindowDC to get the DC of the entire window rather than GetDCEx, that was just because I could interop that from memory and did not have lookup all the flag constants for GetDcEx. And of course the code could do with more error checking.
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace WindowsFormsApplication1
{
public partial class CustomBorderForm : Form
{
const int WM_NCPAINT = 0x85;
[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr GetWindowDC(IntPtr hwnd);
[DllImport("user32.dll", SetLastError = true)]
public static extern int ReleaseDC(IntPtr hwnd, IntPtr hdc);
[DllImport("user32.dll", SetLastError = true)]
public static extern void DisableProcessWindowsGhosting();
[DllImport("UxTheme.dll", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern IntPtr SetWindowTheme(IntPtr hwnd, string pszSubAppName, string pszSubIdList);
public CustomBorderForm()
{
// This could be called from main.
DisableProcessWindowsGhosting();
InitializeComponent();
}
protected override void OnHandleCreated(EventArgs e)
{
SetWindowTheme(this.Handle, "", "");
base.OnHandleCreated(e);
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
switch (m.Msg)
{
case WM_NCPAINT:
{
IntPtr hdc = GetWindowDC(m.HWnd);
using (Graphics g = Graphics.FromHdc(hdc))
{
g.FillEllipse(Brushes.Red, new Rectangle((Width-20)/2, 8, 20, 20));
}
ReleaseDC(m.HWnd, hdc);
}
break;
}
}
}
}
Btw. I called DisableProcessWindowsGhosting, this will stop the OS from drawing the non-client area if the application takes too long to respond to windows messages. If you do not do this, then in some situations the border will be renderd but your adornments will not be shown. So that depends on your requirements it that is right for you or not.
***Aero supported solution***
Prompted by the comment from #TheCodeKing, I thought I would take another look at this. It turns out this can be done in a fully documented way while supporting Aero. But it is not for the faint of heart. I will not provide a complete solution here, there are still some kinks to workout, but it does the basics.
This code/solution is based off the Win32 example which can be found at the following location
http://msdn.microsoft.com/en-us/library/bb688195(VS.85).aspx
In principal what you need to do is the following.
Extend the client area of the window to cover the Frame. This is done by handling the WM_NCCALCSIZE message and returning 0. This gives the Non-Client area a size of 0 and therefore the client area now covers the entire window.
Extend the Frame into the client area using DwmExtendFrameIntoClientArea. This gets the OS to render the Frame over the client area.
The above steps will give you a windows with the standard glass frame excluding the system menu (Window Icon) and the title. The minimize, maximize and close buttons will still be drawn and will work. What you will not be able to do is drag or resize the window, this is because the frame is not really there, remember the client area covers the whole window, we have just asked the OS to draw the frame onto the client area.
Now you can draw on the window as normal, even on top of the frame. You can even put controls in the caption area.
Finally, allow the DWM to handle hit-testing for you, by calling DwmDefWindowProc from your WndProc (before you've processed it). It returns a boolean indicating whether the DWM handled the message for you.

Simple Solution:
Step 1: Create a Windows Form (this will be your custom title bar)
-Set Form Border Style to None
-Add whatever controls you would like to this
-I will name this custom form "TitleBarButtons"
Step 2. In the from that you want to use this custom control in add
titleBarBtn = new TitleBarButtons();
titleBarBtn.Location = new Point(this.Location.X + 100, this.Location.Y+5);
titleBarBtn.Show();
titleBarBtn.Owner = this;
To your constructor... you can mess with the offsets this just fit in a nice position for my app
Step 3. Add the move event to your main form
private void Form14_Move(object sender, EventArgs e)
{
titleBarBtn.Location = new Point(this.Location.X + 100, this.Location.Y+5);
}
Please let me know if you would like a better explanation of any of the above code.

I think a way to do this would be to handle WM_NCPAINT message (non-client paint) to draw the button, and to handle non-client mouse clicks to know someone clicked on the "button".

Send user input through a windows form

I am looking for a way to pass mouse events through a winform without using Form.TransparencyKey.
If there is no simple way to do this, is there a way to send a mouse event to a given window handle using Win32 API?
Edit
By pass through the winform I do not mean to a parent window, I mean to other applications that reside behind mine.

This may sound overkill, as I saw SLaks's answer..
You would need
The handle of the Window using Handle property
Use pinvoke on the SendMessage Win32API
One of the parameters to SendMessage is WM_LBUTTONDOWN
Here's a declaration for the SendMessage
[DllImport("user32")] static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
Here's the constants used:
public const int WM_LBUTTONDOWN = 0x201;
public const int WM_LBUTTONUP = 0x202;
Typical Invocation:
SendMessage(someWindow.Handle, WM_LBUTTONDOWN, IntPtr.Zero, IntPtr.Zero);
SendMessage(someWindow.Handle, WM_LBUTTONUP, IntPtr.Zero, IntPtr.Zero);
The invocation is an example of how to send a mouse left-click to a specified window.
I used pinvoke.net to obtain the correct API.
Hope this helps,
Best regards,
Tom.

The answer is actually much easier than I thought it would be.
This SO answer got me where I needed to be:
Transparent Window (or Draw to screen) No Mouse Capture
Also found what looks like a c++ implementation if you want some working code:
Transparent Window (or Draw to screen) No Mouse Capture