GetClassInfoEx fails when called for a class that was defined in another process, for both string name and class atom. I have observed that ConsoleWindowClass, which is returned for console windows, doesn't work when passed to GetClassInfo(Ex), as it is defined in conhost.exe.
Is it possible to obtain the class info from this process, possibly with ReadProcessMemory, without having to inject custom code into the process?
Related
I have defined a class like this:
Class Foo
Public SomePublicProperty
Public Function init(p_somePublicProperty)
set init = Me
SomePublicProperty= p_somePublicProperty
End Function
End Class
And then consumed that in my global.asa Application_OnStart lke this:
Dim fooInstance
Set fooInstance = New Foo.init("Some data")
fooArray = Array(fooInstance)
Application("fooArray") = fooArray
Which works fine but when i get the value back out of the application store on another page i can't get at the property...
fooArray = Application("fooArray")
fooArray(0).SomePublicProperty 'This line returns an error - Object doesn't support this property or method
I have tried putting the class definition into the second page, but it doesn't help.
What have I missed?
I have just found this question. Am I right in assuming the same rule re serialization applies equally to the Application object? and so i shouldn't try and do this?
Unfortunately you can't do this, here is a the best explanation I could find as to why;
From Can I store VBScript class objects in a Session variable?
This is because VBS classes are NOT true classes. They are really just in-memory collections of info, and there is no way to guarantee (for example) that an instance that is stored in one page will even come close to matching the class definition in another page.
This is not the same as using Server.CreateObject() COM objects which can be stored and retrieved from both the Application and Session objects.
You have a couple of options;
Serialise the object yourself, in a structured string then use this to de-serialise the object when needed.
Create a COM wrapper for your VBScript class and stop using Class statement altogether. As COM objects can be stored in Application and Session objects this should work as long as the COM class is single threaded.
Convert your class into an Array and use this instead.
Useful Links
Application Object (IIS)
Setting the Scope of COM Objects in ASP Pages - Giving an Object Application Scope
I guess my question is relatively easy for those of you who spent time dealing with Win32 API.
So my question is:
After initializing a WNDCLASSEX instance we need to "register" it using the "RegisterClassEx" function, why? Why do we do that? What's the meaning of this registration and in what cases I need to register things?
The ATOM returned by RegisterClassEx uniquely identifies your "window class" which can then be referred to in other windows APIs. [MSDN]
Effectively it is a hash so as to reduce the amount of data processed each time a window is created or looked for. It does also mean that multiple windows with same features can be easily created and identified.
I was addressing the practical reasons above. Hans Passant's answer correctly explains this is the OO class concept provided for C. Further MSDN example.
The word Class in the function name is significant. When you write code in an object oriented language, like C++, Delphi, Java or C# etcetera, then you use the class keyword to create objects that have behavior. But the winapi was designed to be used from C, a language that doesn't have such functionality. The RegisterClassEx() function is an emulation of that, it lets you create a window that "derives" its behavior from a named class, behavior that you can override. With every window that you create using that class name behaving identically.
The WNDCLASSEX structure you pass gives a window its default behavior. The most significant members of this structure are:
lpszClassName. That's the equivalent of the C++ class name. You can later call CreateWindowEx() and pass that name to get a window that behaves a certain way. Windows itself calls RegisterClassEx() to register several of its built-in window classes that you then can readily re-use in your own code. "EDIT", "BUTTON" and "LISTBOX" are good examples of that.
lpfnWndProc. This is what gives a window class its specific default behavior. The address of its window procedure that implement message handlers for specific messages. You can further customize the default behavior, in other words "derive" your own class from the base class, by specifying another window procedure in the CreateWindowEx() call. Such a window procedure must always call DefWindowProc(), the equivalent of calling the base class method. Or in other words, a window has one virtual method.
hIcon, etcetera. These are the equivalent of properties of the base class, they set default values that affect the default message handlers. Helping you to keep your window procedure simple. It is for example rarely necessary to write a message handler for WM_ERASEBKGND, the hbrBackground member sets the default background for a window.
Windows requires you to call RegisterClassEx() even if you don't plan on re-using a window. Which is by far the most common usage of the function in your own code. You don't start to really take advantage of it until you write a library that implements controls, windows that other code can use. Like "EDIT".
Whenever a core class is initialized, a line is written to the debug log. For example, if CI_Model is instantiated, you'll see a "Model Class Initialized". I want to suppress this.
When I inherit from CI_Model, I call the parent constructor, which outputs that line. In the inherited class, I am also outputting a similar line. For example "CustomModel Class Initialized".
Unfortunately, this gives me two lines in the logs, one that is helpful, and one that is redundant.
The simplest solution would just be to go into system/core/Model.php and comment the line out.
Another approach would be to log the message from your CustomModel class with a message level other than debug. Then, update the log threshold in application/config/config.php to disable logging of debug messages. The downside to this approach is that you won't log all of the other system messages.
If all you're really trying to accomplish is to remove that one log message, I don't see any harm in just going into the core class and removing the line.
I am trying to implement AssemblyInitialize/AssemblyCleanup attributes in my Microsoft Visual Studio 2010 for the exact purpose as stated here. That link even describes the process which I need to follow to implement the code.
A quick summary of that purpose is to create an initial block of code which will run right before any test no matter which of the codedUITests I run in the solution and then a block of code which will run after the last codedUITest is completed. Example: I need to open up a specific application, then run a series of codedUITests which all start at that application and which are executed in any order, then close the application after everything is finished; this is more efficient than opening/closing the application for each codedUITest.
What I don't understand is where I need to place the code laid out at the bottom of that page (also shown below). I stuck all that code right under my 'public partial class UIMap' and the code runs except it runs the 'OpenApplication' and 'CloseApplication' commands before/after each CodedUITest instead of sandwiching the entire group of CodedUITests.
How do I implement the code correctly?
Update:
I discovered AssemblyI/C last night and I spent 3 hours trying to
figure out where to put the code so it works. If I put the
AssemblyInitialize at the beginning of a specific test method then:
1) It still wouldn't run - it was giving me some error saying that
UIMap.OpenWindow() and UIMap.CloseWindow() methods need to be static
and I couldn't figure out how to make them static.
2) Wouldn't the specific [TestMethod] which has the AssemblyI/C on it
need to be in the test set? In my situation I have a dozen
CodedUITests which need to run either individually or in a larger
group and I need to get the AssemblyI/C to Open/Close the window I am
testing.
You've added the methods to the wrong class. By putting then into the UIMap partial class, you are telling the runtime to run those methods every time you create a new UIMap instance, which it sounds like you're doing every test.
The point of the ClassInitialize/ClassCleanup methods is to add them to the class with your test methods in it. You should have at least one class decorated with the TestClass attribute, which has at least one method decorated with a TestMethod attribute. This is the class that needs the ClassInitialize and ClassCleanup attributes applied to it. Those methods will run one time for each separate TestClass you have in your project.
You could also use the AssemblyInitialize and AssemblyCleanup attributes instead. There can only be one of these methods in any given assembly, and they will run first and last, respectively, before and after any test methods in any classes.
UPDATE:
AssemblyInitialize/Cleanup need to be in a class that has the TestClass attribute, but it doesn't matter which one. The single method with each attribute will get run before or after any tests in the assembly run. It can't be a test method, though; it has to be a static method and will not count as a "test".
I understand that CoCreateInstance finds the COM server for the given class id, creates the object instance for that id and retrieves an interface from that object instance. CoGetClassObject() finds the COM server for the class id, creates an instance of the class factory for that class id and retrieves that class factory interface which can be then used for creating actual objects.
How else do these functions differ when used to create objects on the same machine? Do they work the same way but only cause different code to be invoked in the exactly same COM server?
CoGetClassObject essentially returns you a pointer to a factory for a particular interface. Under the hood, CoCreateInstance uses CoGetClassObject. The advantage of calling CoGetClassObject is that it allows you to only have to create the class factory once if you want to create many instances of a particular object.
The MSDN section on CoGetClassObject has a brief discussion on how you can take advantage of this functionality.
http://msdn.microsoft.com/en-us/library/ms684007(VS.85).aspx
One scenario in addition to what JaredPar said - CoGetClassObject returns you a class factory (calls DLLGetClassObject exported function of your DLL in case of inproc server). Class factory is used to instantiate coclass. CoCreateInstance internally calls CoGetClassObject, gets the required class factory and then uses it to instantiate the coclass you requested. When calling CoCreateInstance, you cannot delay creation of the coclass. There are times when creation of coclass could be expensive and you would want to delay its creation but still have access to the class factory so you could instantiate the coclass on demand.