I need my Visual Studio extension to react to debugging events. I've registered a IDebugEventCallback2 and I'm receiving events, but all I get for each event is an opaque IDebugEvent2 and a Guid, many of which are not only undocumented but don't appear anywhere on the web (or in my registry).
My specific requirement at the moment is to know when the process is Continued - ie. the user has hit Continue, Run to cursor, etc. What Guid should I be looking for?
Or is there some other event family that I should be subscribing to?
(More generally, is there some way I'm missing to find out about the events that are delivered to my IDebugEventCallback2::Event callback, when many of them don't appear in MSDN or anywhere else? Thanks!)
There is no easy way to do this. Actions such as Continue and Run to cursor are abstractions implemented by Visual Studio and do not correspond to any unique event(s) with respect to the debug engine. The debug engine event reporting interface IDebugEventCallback2 will enable you to get notified only on fine-grained events such as when creating a breakpoint or reaching a breakpoint.
While Visual Studio enables you to perform actions such as Continue and Run to cursor programmatically, it does not provide a direct way to get notified when they are taken.
You can use EnvDTE.DebuggerEvents.OnXxx events to get notified when something is about to happen. In particular, the OnEnterBreakMode event enables you to intercept a breakpoint hit and possibly take an action. You can also inspect all the details of the reached breakpoint(s) using the current EnvDTE.Debugger inside the event handler.
Now with some effort, you can use these constructs to implement events that correspond to all Visual Studio debugging actions including Continue and Run to cursor accurately. If you require additional events not provided by EnvDTE.DebuggerEvents (such as when a breakpoint is inserted), you have no choice but use IDebugEventCallback2.Event. In this case if you have specific events in mind, please mention them explicitly and I might be able to tell you the corresponding IDebugEventCallback2.Event GUIDs.
You probably got off on the wrong foot here, the IDebugXxx interfaces were really intended to create your own debugging engine. Still useful perhaps to see what is going on in the existing engine, you are suppose to use QueryInterface() to discover the specific interface that matches the event. Like IDebugEngineCreateEvent2, IDebugProcessCreateEvent2, IDebugProcessDestroyEvent2, etcetera. There are a bunch of them, they are listed in the VSSDK\VisualStudioIntegration\Common\Inc\msdbg.h header and include their IID.
Best thing to do is peek at this sample, it shows how to crack the event notification into the specific interfaces. The AD7Events.cs source file shows the wrappers. Do keep in mind that this sample was made to show how to create an engine, not how to use the one already built into VS.
But yes, you are not going to get a "continue debug" event out of this. A debugging engine does not need that event since it is already responsible for taking care of that by itself. It already knows when it calls IDebugProgram3::Continue().
Surely what you are looking for is IVsDebugger.AdviseDebuggerEvents(). That's the one that tells you what the built-in debugger is doing. You need to pass an object of a class that implements IVsDebuggerEvents, your OnModeChanged() method will be called with a DBGMODE notification. I don't see a lot of fantastic examples that demonstrate usage, this web page might be helpful.
Related
I want to prevent users from closing a window by Alt + F4 or by clicking the close button.
How to achieve this?
I guess the windows API can do it, but I don't have any experience, and I can't find a specific solution.
Of course, it's good to be able to implement it,don't have to use a specific API.
Background: it is very difficult to find the last place in Word after closing it for a few days. After word2013, word2013 brought with it a way to return to the previous reading position, but that thing is very unstable and often can't be saved. When word is closed, I want to stop closing and pop up a notice to remind me to add a bookmark before exiting.
EDIT: This won't work, as it turned out. At least the message hook won't work because the message is posted and not sent, and about the CBT hook I'm not sure either, and I can't test it at the moment to give an evidence-based statement. The solution is probably to subclass the window but this is also non-trivial and I can't explain it properly and with working examples right now. I can't delete this answer though because it already has a comment. See here for more info. So take it with a grain of salt. I'm turning the answer to community wiki, feel free to edit it and fix/improve the solution!
EDIT2: Seems even subclassing won't be enough because Word is doing things its own way.
You need a windows hook. Either a CBT hook or a getmessage hook will do.
You have to create a DLL for this to work. The hook handler must be located in the DLL. It must have the same bitness as Word (probably 64 Bit). Then you call SetWindowsHookEx to install a global hook.
In the hook, you will have to check whether the current action is a window-closing attempt (in a CBT hook you would check for a HCBT_SYSCOMMAND of SC_CLOSE, in a getmessage hook you would check for a WM_CLOSE message), and whether it is about a Word window (for example using the window class - not sure if it has a recognizable class, you'd have to check - or the process' executable file name which you can get using GetModuleFileName since you will run inside Word's process) and prevent the action (by returning 1 from a CBT hook or returning 0 from a getmessage hook - to allow, call CallNextHookEx).
My UWP app goes into UI freeze state sometimes and I don't know why。 I've checked the code about view model and async-await calls. And I've tried to use the performance profile tool in Visual Studio to get timeline but it only shows the time and duration time about the UI freeze. I have run out of ideas now.
I tried the dotTrace but it seems that I cannot use it to profile UWP application. Even I " disable the Compile with .NET Native tool chain option in Visual Studio (via the menu Project | Properties... | Build) and rebuild the project."
https://learn.microsoft.com/en-gb/visualstudio/profiling/profiling-feature-tour?view=vs-2019
There are many reasons for UI freezing, including code endless loops, asynchronous methods are not handled properly, program errors, etc.
Most of them occur in asynchronous method processing and UI rendering.
When calling asynchronous methods, use the async/await keywords, like:
//define
public async Task asyncMethod()
{ }
//use
await asyncMethod();
Reduce resource consumption when rendering a large number of data templates through virtualization.
If you have a large list to render, if virtualization is not enabled (referring to controls with virtualization, such as ListView), or used, but the conditions of virtualization are destroyed (such as adding ScrollViewer outside ListView ), This will also cause the UI to freeze and will not return to normal until the list is rendered.
Please check your code for the above problems, or provide a minimal reproducible demo so that we can analyze where the problem occurs.
Best regards.
I would suggest you try to use the Visual Studio debugger to find out what the code is doing.
First, make sure that you are set "Debug" mode and that the debugger is going to run on "Local Machine" (there are other options here, but I'm trying to keep things simple).
Then, click on the "Local Machine" button to run your app using the debugger.
Once your app freezes, click on Debug-Break All:
After that, I suggest you use the various Debug commands to further debug your application.
For example, you can use the "Call Stack" menu item/window to view what your code is doing. You can also use the "Threads" menu to see what threads are running. If you have suspect areas in your code, you might consider adding System.Diagnostics.Debug.WriteLine() statements to print out informative messages, and then use the "Output" menu item/window to see what is happening.
If your app first freezes, and then crashes after some time, then this could be because your tasks don't have correct exception handling. You might consider adding an UnobservedTaskException handler to your code to help you find this problem.
I'm working on a little macro record/replay tool which can automate a few very old Visual Basic 6 GUIs we have. To do so, I'm identifying the controls by their name (the value of the name property of a control, that is).
One part of this tool needs to determine the name of a control given its HWND. For newer Visual Basic applications which were done using VB.NET, I can use the WM_GETCONTROLNAME window message. This works nicely.
However, this message is not understood by older windows. Is there any way to do this for controls of Visual Basic 6 applications? A solution which does not require being in the process of the GUI would be preferrable, but if I had a solution which only works inside the GUI process then that would be acceptable as well (since I can do the injection myself).
UPDATE: One thing I just tried, this moderate success: I used the AccessibleObjectFromWindow to check for implementations of the IAccessible interface of the object which shows the given HWND. In case I get an implementation (it seems that many [all?] Visual Basic controls implement this interface), I use the accName property to read out the "accessible name". Sometimes this does yield a useful string, but usually it doesn't.
I believe the only way would be getting inside the process and obtaining a pointer to the Form object, yet I have no idea how to do it from outside.
Is it possible you add support for the WM_GETCONTROLNAME to those older applications?
Or maybe, you could identify the controls by some other, natively-available properties?
Other that that, as Raymond is saying, there isn't much you can do.
Can you modify the vb6 apps? if so in each form load event you could iterate me.controls and use the SetProp(ctrl.hwnd, "MYNAME:" & ctrl.name, 0) api to add the name to the window's own property list, then in your other app you can EnumProps(ctrl_HWND) looking for the one that begins with MYNAME: and parse out the value.
In other words, can I count on a control ID as a reliable identifier?
From some reading I've done, it sounds like .NET controls can have control IDs that change with every run, is this so for Win32 apps as well, or are they something that's hardcoded in the source?
The window/control in question is actually an Internet Explorer dialog if that helps.
In general win32 dialog resource IDs do not change when you run the app. However, they are internal implementation details and as such they are subject to change whenever an update (patch, service pack, major release) to the application is made.
In general all of IE's dialogs use hard-coded control IDs. There may be some that are dynamic. If you give the specific control I might be able to give you a better answer.
The answer is "it depends on the circumstances, but in the majority of programs, these will not change across multiple executions." In general, a control ID or resource ID will be the same across every execution of the same program.
In most implementations, resources are stored in the resource section of the PE executable and are assigned a resource ID within that data structure. Usually, the developer specifies the resource in a .rc file.
The exceptional case is via APIs such as CreateDialogIndirect() which allow IDs specified through the API at runtime. Such dynamic creation is uncommon, however. Consistency of resource IDs and control IDs is the expected condition, so even in the case of the CreateXXXIndirect() API, users of the API would be ill-advised to chose a varying ID.
Microsoft has spent years trying to deal with applications which embed assumptions about internal windows implementation details. One of the biggest causes of compatibility problems for IE8 was caused by applications which made assumptions about the window order of IE controls. When the UI was changed in IE8, the controls moved and a number of browser plugins broke hideously.
In general you should never ever make assumptions about controls in an application that you didn't write - your code WILL break in the future (not might break, will break).
As a general rule, no they don't change between runs. Control IDs are usually specified with a dialog template, and that's a static resource compiled into an .exe or .dll. Controls can also be created using a regular call to CreateWindow or CreateWindowEx. In such cases, the ID is usually a constant, but it could be anything in principal (even a random value).
In any case, if you're planning to muck around with a dialog in another application, then you are asking for trouble. Control IDs can and do change between different versions of a program.
It depends on the control. Controls that are dynamically created could have a different ID every time they are created. Controls based on static dialog resources will have static IDs.
Even if a dialog is backed by a dialog resource template, controls can be added dynamically at runtime and those controls could have dynamically generated IDs.
Depending on your intent, it may be acceptable to store and reuse it for future lookups or traces; but in general it isn't safe.
If the window is based upon a dialog template, items declared in the template generally don't change. It is perfectly safe under typical circumstances to use these as identifiers.
Sometimes the window class name or a portion of it can be used as an identifier instead, depending on the window host.
If the dialog is one of the standard prompts from internet explorer, you may want to use text stored in adjacent controls or the dialog caption as additional verification info (if localized versions of IE are not an issue). If the dialog is a window that embeds an instance of MSHTML/IE; none of these options may be viable- but you can use OLE accessibility to get at the document shown and then browse the DOM from there.
I am trying to build my own little toolbox for Vista.
One of the features is a "window placeing tool" which places the windows at saved position. Another tool I could imagine are extensions to firefox or thunderbird...
For these tools to work, I need them to be able to capture "Events" in Vista.
To give you a concrete example:
Explorer Opened New Window
User started Firefox
Mouse moved
For the mouse case, there are some examples for C#.
I also know about the directory watcher, nice little helper.
Want I now need is the "new window opened event"
Any idea how to monitor this, without iterating the current window list every 5 seconds (I already know how to get Windows using the DLLImports, and getting Processes using managed code. But I have no Event when the explorer process opens a new windows)
Thanks for your help,
Chris
What you're talking about doing is not simple by any stretch.
You're going to need to register a hook, and you're going to have to build a callback procedure that gets called within another process's execution context -- this is not going to be .NET code (probably C instead), and will have to be in a DLL. That callback procedure will get called every time a certain class of events happens. It will examine the events it receives and filter out the ones you're interested, then send your application the notifications you want (probably via PostMessage). You'll then tap in to your application's main message loop to intercept those messages, and from there you can fire a .NET Event, or whatever you want.
Writing hook callbacks is tricky stuff because the code gets run within another process, not your own, and the memory management and concurrency issues take a bit of forethought. For that same reason, it's not going to be done in C#. Ideally, though, this callback code will be very small and very fast, since it's going to get called so often.
Also note that while perfectly "legal" in Win32, these system hooks have an immense amount of power and are commonly used by malware to change the way your system works. For that reason, you may run afoul of antivirus software if you attempt to do this sort of thing on a customer's computer.
Also note that the far-reaching effects of system hooks also means that simple programming mistakes can take down your whole system, which you will probably discover for yourself at some point while debugging; so save everything before you hit "run".
Good luck!
EDIT
Did a bit more search to see if there's any way to write the hook proc in C#, and came up with this:
How to set a Windows hook in Visual C# .NET
This is almost what you're looking for, but not quite. Hook procedures can either be global (which means that they run on every application) or thread (only runs within your application). The document states that:
Global hooks are not supported in the .NET Framework
Except for the
WH_KEYBOARD_LL low-level hook and the
WH_MOUSE_LL low-level hook, you cannot
implement global hooks in the
Microsoft .NET Framework. To install a
global hook, a hook must have a native
DLL export to inject itself in another
process that requires a valid,
consistent function to call into. This
behavior requires a DLL export. The
.NET Framework does not support DLL
exports. Managed code has no concept
of a consistent value for a function
pointer because these function
pointers are proxies that are built
dynamically.
Which means, again, to monitor things that go on outside your application's view, you need to set a global hook, which can't be written in .NET.
I have exactly the same issue as this, and I think I have a workable solution. Initially I looked into a similar option to the one mentioned by 'tylerl'. In my case however, instead of using 'SetWindowsHookEx', I attempted to use the similar function 'RegisterShellHookWindows'.
Unfortunately, this only succeeded in providing me with notifications of when a subset of windows are created/destroyed. The only windows which it provided notifications for are those shown on the taskbar.
Since I didn't fancy hacking into other processes, or writing the native code which would be required for SetWindowHookEx, I tried digging into the .NET automation APIs introduced in .NET 4.0, and I think this has the answer to your problem (at least as far as detecting when windows are opened / closed).
Here's a code snippet for using this API to detect windows being opened/closed:
using System.Windows.Automation;
private void StartMonitoringForWindowEvents()
{
Task.Factory.StartNew(() =>
{
AutomationEventHandler windowOpenedHandler = new AutomationEventHandler(OnWindowOpened);
System.Windows.Automation.Automation.AddAutomationEventHandler(
WindowPattern.WindowOpenedEvent, AutomationElement.RootElement,
TreeScope.Descendants, windowOpenedHandler);
});
}
private void OnWindowOpened(object source, AutomationEventArgs eventArgs)
{
try
{
AutomationElement sourceElement = (AutomationElement)source;
string message = string.Format(
"Automation.WindowOpened PID: {0}, Handle: {1}, Name:{2}",
sourceElement.Current.ProcessId,
sourceElement.Current.NativeWindowHandle,
sourceElement.Current.Name);
Debug.WriteLine(message);
// for each created window, register to watch for it being closed
RegisterForClosedWindowEvent(sourceElement);
}
catch
{
}
}
private void RegisterForClosedWindowEvent(AutomationElement element)
{
try
{
string elementName = element.Current.Name;
int processId = element.Current.ProcessId;
int nativeHandle = element.Current.NativeWindowHandle;
AutomationEventHandler windowClosedHandler = new AutomationEventHandler(
(ignoreSource, ignoreArgs) => OnWindowClosed(nativeHandle, processId, elementName));
System.Windows.Automation.Automation.AddAutomationEventHandler(
WindowPattern.WindowClosedEvent, element,
TreeScope.Element, windowClosedHandler);
}
catch
{
}
}
private void OnWindowClosed(int nativeHandle, int processId, string elementName)
{
string message = string.Format(
"Automation.WindowClosed PID: {0}, Handle: {1}, Name:{2}",
processId,
nativeHandle,
elementName);
Debug.WriteLine(message);
}
You will need to add a reference to the assemblies 'UIAutomationClient' and 'UIAutomationClientTypes'.
Here's a link to the MSDN documentation (you'll probably particularly want to take a look at the information on events):
http://msdn.microsoft.com/en-us/library/ms747327.aspx
Important implementation Notes:
1.) Notice that in the sample, I used a task factory to register for reception of the automation events. It's particularly important to avoid using the UI thread when registering for automation events or generally interacting with the automation APIs. Doing so can (and usually quickly does) result in a deadlock. Therefore, I use the task factory to ensure registration is done via the thread pool.
This also means, that the events will be received on the thread pool... So, if you need to perform any UI updates, you will have to marshal these across to the UI thread.
2.) You'll also note, that I capture any needed information on the element which may be closed, at the time of registration (using a closure). This is because, once the element is closed, we will no longer have access to this information - since the element has been destroyed.
Phil
The answer is not C# (or .Net) specific. You'll need to call SetWindowsHookEx( WH_CBT, ... ). This will allows to know when a window is created, destroyed, moved, sized, etc. You'll also need to get the relevant information from the window to identify if its one you need to do something about. Perhaps GetClassInfo, GetWindowLong, and GetWindowText.
The problem with the SetWindowsHookEx is that in order to get events from every window you need to have a separate win32 dll with the function in question exported. Although you might have success with the procedure outlined here.
To expand upon Joel Lucsy's answer, you need to use the Win32 API. However, there's a nice library, the Managed Windows API, that provides an object-oriented wrapper over common APIs. It may have what you need.