This may be a long short or not even possible but no harm in asking.
What I am trying to do is monitor an application for any new windows it creates in its MDI control. I have implemented hooking in C# and can capture the MDICREATE window message but because I need to get information about the window after is has been created the MDICREATE message isn't much help because at that stage the window hasn't been created in the other application yet.
Without going into to much detail I just need to be able to see when a new window has been created.
Is this possible?
Thanks
I'm not aware of another message that gets the info that you are looking for off hand. But if that message works for you, you could hook that message and then do another scan of the windows to find the one you are missing. You can enumerate the child windows of the parent window. Use Spy++ to see the exact window hierarchy.
If you can watch for a particular function call, I would use some kind of hooking library to grab that (EasyHook comes to mind).
You can hook the MDI create function (assuming there is one), watch for that, then inn your code, call the original and do any lookups using the returned value. You'll have access to the returned value and any parameters, so you should be able to get some info out of those.
Two options off the top of my head.
Hook the WM_MDIACTIVATE event, the first time the window is being activated, use a flag to determine the first time the window is being activated.
If you need to run your code after the WM_MDICREATE or WM_MDIACTIVATE, you can post a new custom message from one of these messages, which is then handled after these messages have completed. You then write your code to handle the custom message.
Related
i have work on an app that manipulate some application context menue to extend its functions, i have checked all the common posts here on stackOverFlow on how to manipulate the menu context using Windows api in C# using functions like GetMenu(...), InsertMenuItem(...), ShowOwnedPopups(...) and that comes in vain, here is the scenario, the application i wanna manipulate it context menu has many context menus in many parts but i want to manipulate certain one which belongs to the viewer part. so i have used spy++ to figure the the handle of the viewer and a send a message WM_CONTEXTMENU using SendMessage(...) function. the menu finally appears and i have its handle.
i guess after i get the handle it would be constant for the life time of the program for the single running time, but i figured out that the handle is changing every single time a i have clicked right click. and the parent of the context menu isn't the viewer area itself but the desktop that's was disappointing.
so i have two problems
1- i can't get the handle directly as using GetMenu(...) passing the handle of the viewer returns null, after some search if found that the context menu has a class name of "#32768" so i have filtered all the open windows to get the one that its class name equlas "#32768". and now i can access the handle from my c# code not from the spy. but here is an comming issue: if there is a sub menue.. it also have the same class and unfortunately this is totally logical :/
2- i can't get the context handle before it is shown and if it is shown, i can't manipulate it as i know. The second thing is that the context handle continuously changes every single time i right click the mouse. so i can't pass the first time i click then save the handle for the next clicks to make it work.
any suggestion are very welcomed.
First of all you should figure out if you can just send it a WM_COMMAND message to perform your command. A context menu might not use that message but if the application also has a normal menu then it is likely that it will handle the message. Note that the command id might change between program versions.
All Win32 HMENU menus use the same class and MN_GETHMENU is the only related documented message.
The recommended solution is to use UI Automation/MSAA to navigate the UI of other applications.
I am trying to hide all the windows of my app when a users session time's out. That works great; however, when a MessageBox is left open when the app times out the message box still is there. I want to be able to close the message box or at least hide it. I've looked up hwnds and hinstances and I don't quite know if thats what I am looking for to accomplish this. I thought this would be fairly easy as I thought MessageBox inherited from Window and of course it doesn't. And a top of that you cannot create an instance of message box to keep track of it. At this point I am not sure what to actually do or what to actually search for.
I am in the process of trying to figure some stuff out using reflection. I can create an instance of MessageBox using reflection but don't think I can call Show() using an instance.
Short answer: just create your own window that looks like a message box
Long answer:
Message boxes are normal WinAPI windows (they have an HWND and can be manipulated by the native API windowing functions) however they are not WPF windows and don't have an associated Window object.
Since they are normal windows you can get their HWND (using FindWindow/ FindWindowEx/ EnumWindows) and trick them into closing (for example, by simulating a Cancel button click)
However, because message boxes are not designed to be manipulated like that this trick has some nasty pitfalls you have to take care of.
And, because message boxes are so simple and you can easily create a message box clone it's just easier to create the close and not take care of all the message boxes corner cases.
I've been looking around for quite a while, and can't seem to find a good way to do this.
Basically I have a C# process using WPF (which has no visible window), that I need to handle WM_ events in (such as WM_CLOSE or WM_DESTROY for example; so that I can elegantly shutdown when a user chooses to log off or restart their machine).
There are a number of solutions I've seen out there that suggest using System.Windows.InteropServices to call AddHook and provide it a pointer to a function that then becomes the WndProc. The problem with this is, as far as I can tell, it depends on the window actually being visible (and in this case there is no window).
Another way that's suggested but doesn't work is to override the WndProc method of a WinForm, but this process has no visible forms or windows.
I've also found things referring to a Message-only Window. Some kind of invisible window that still receives WM_ events. From what I've seen, this is only available in a Microsoft.WindowsCE.Forms assembly. I added a reference to this assembly in my project and subclassed MessageWindow as indicated at: http://msdn.microsoft.com/en-us/library/microsoft.windowsce.forms.messagewindow.aspx but it still seems to not work. The breakpoints inside the WndProc are not being hit.
Any clue?
Think about what you are asking- if you don't have a window, how could your application receive a window message (considering that messages are sent to a window's handle).
That's like saying "how can I receive email without having an email address?"
Michael Entin covers windows' behavior during shutdown here.
I am 99% sure that all processes running in a user's session are automatically closed when the user logs off anyway, so this shouldn't be an issue. If you really must handle this window message, you can create a hidden window as per Any way to create a hidden main window in C#?
I want to make an application to intercept all UI events in all the forms of my application and to write them to a log. This data can than be used to see which controls are the most used, in what order, etc. The problem is that I want this to happen automatically, without modifying the existing classes.
I made a prototype that attaches a method to a click event for all controls in a form, but how can this be done for all forms? Reflection needs a target object when manipulating events, but only the startup form can be easily accessed.
Is there a way to hook the constructor of an object? Then I could "inject" my method in all the events of the new form. Or maybe there is another way to do this.
Thanks in advance!
You can install a message filter.
A message filter is an object that implements IMessageFilter. WinForms calls your PreFilterMessage method for every message that passes through your thread's message loop. This is enough to monitor user input across the application (and gives you the option of manipulating it).
In Windows API this is done using local hooks (you can set local mouse hook using SetWindowsHookEx function). This is the proper way to do your task. In C# you need to use P/Invoke in order to get access to SetWindowsHookEx.
One more task would be to match the HWND (windows handle) to corresponding WinForms control.
Read this article for how to do this (via WM_GETCONTROLNAME message).
Also see this question which is a duplicate of yours.
You will have to work with the Win32's API Messages, I guess.
Here's a little example under the form of tutorial.
You should be able to achieve what you want with message filters - no direct P/Invoke to Win32-APIs required!
See the help on the IMessageFilter interface for more info.
When enumerating windows using EnumWindows, I get hundreds of handles instead of one per open window on my desktop.
First of all, i am curious if this is the correct behavior.
Secondly, trying to get a difference between open windows before and after launching a process returns 15-20 new handles. I am wondering if there is a way to filter these based on some flag, i really need just the mainwindow handle.
Any ideas?
To get the main window of a process, use the Process.MainWindowHandle property.
To answer your question, you can see exactly what all of the handles are using Spy++.
In short, many applications will create hidden windows to run message loops.
You can filter within the enum callback by checking IsWindowVisible() & ignoring invisible system/message sink windows.