I'm looking into writing an addin (or package, if necessary) for Visual Studio 2005 that needs watch window type functionality -- evaluation of expressions and examination of the types. The automation facilities provide
Debugger::GetExpression, which is useful enough, but the information
provided is a bit crude.
From looking through the docs, it sounds like an
IDebugExpressionContext2 would be more useful. With one of these it
looks as if I can get more information from an expression -- detailed
information about the type and any members and so on and so forth, without having everything come through as strings.
I can't find any way of actually getting a IDebugExpressionContext2,
though! IDebugProgramProvider2 sort of looks relevant, in that I
could start with IDebugProgramProvider2::GetProviderProcessData and
then slowly drill down until reaching something that can supply my
expression context -- but I'll need to supply a port to this, and it's
not clear how to retrieve the port corresponding to the current debug
session. (Even if I tried every port, it's not obvious how to tell
which port is the right one...)
I'm becoming suspicious that this simply isn't a supported use case, but with any luck I've simply missed something crashingly obvious.
Can anybody help?
By using IDebugExpressionContext you'll ultamitely end up getting ahold of an instance of IDebugProperty. This interface is implemented by the Expression Evaluator service. This is, typically, a language specific service. It's designed to abstract out the language specific details of evaluating an expression. It understands much higher level commands like "Evaluate", and inspection.
I don't think you're going to get what you're looking for though because you can't get ahold of any kind of type object this way. Nearly all of the inspection methods return their results in String form. For example you won't get the type Int32 but instead the string "int". This makes type inspection next to impossible.
I don't believe what you're trying is a supported case. The type system being evaluated doesn't exist in the current process. It exists in the debuggee process and is fairly difficult to get access to.
There's a hack you could do to get more information about the type of a variable you've evaluated using Debugger::GetExpression method.
You could evaluate "AppDomain.CurrentDomain.GetAssemblies()" to get all the assemblies loaded into the debugee, and cache them in your add-in. You may also need to listen for new assemblies being loaded onto the AppDomain.
Then, run the following:
Expression myExpression = Debugger.GetExpression(...);
Expression typeRefExpression = Debugger.GetExpression("typeof(" + myExpression.Type + ").FullName"
once you have the TypeFullName, you can search inside your assemblies cache for a matching System.Type, and once you have that, you can dig into it all you want using the standart Reflection API.
Note that this will only work in C#, because of its "typeof" keyword. You'll have to use a different keyword for VB.Net, for example.
Related
I am trying to see if there is a way to get the contents of a datagridview that is inside a top level window using Windows API's. I am using Visual Basic for this, but could also use C.
I doubt you could use the WinAPI to drill into a .NET app's DGV to get any meaningful information. But you might be able to using Reflection which enables you to obtain information about assemblies and the types defined within them, such as classes, interfaces, and value types. The ops are contained in the System.Reflection namespace.
Its fairly slow, so it is often a last resort, and the methods and such are pretty dense (convoluted) because you are getting at the information the 'long way around' by examining the Types and then asking the type for information.
This project shows how to access information in a different executing assembly. Given enough time and work and study, it should give you an idea how to do what you are asking.
I'm looking at a piece of very old VB6, and have come across usages such as
Form5!ProgressBar.Max = time_max
and
Form5!ProgressBar.Value = current_time
Perusing the answer to this question here and reading this page here, I deduce that these things mean the same as
Form5.ProgressBar.Max = time_max
Form5.ProgressBar.Value = current_time
but it isn't at all clear that this is the case. Can anyone confirm or deny this, and/or point me at an explanation in words of one syllable?
Yes, Form5!ProgressBar is almost exactly equivalent to Form5.ProgressBar
As far as I can remember there is one difference: the behaviour if the Form5 object does not have a ProgressBar member (i.e. the form does not have a control called ProgressBar). The dot-notation is checked at compile time but the exclamation-mark notation is checked at run time.
Form5.ProgressBar will not compile.
Form5!ProgressBar will compile but will give an error at runtime.
IMHO the dot notation is preferred in VB6, especially when accessing controls. The exclamation mark is only supported for backward-compatibility with very old versions of VB.
The default member of a Form is (indirectly) the Controls collection.
The bang (!) syntax is used for collection access in VB, and in many cases the compiler makes use of it to early bind things that otherwise would be accessed more slowly through late binding.
Far from deprecated, it is often preferable.
However in this case since the default member of Form objects is [_Default] As Object containing a reference to a Controls As Object instance, there is no particular advantage or disadvantage to this syntax over:
Form5("ProgressBar").Value
I agree that in this case however it is better to more directly access the control as a member of the Form as in:
Form5.ProgressBar.Value
Knowing the difference between these is a matter of actually knowing VB. It isn't simply syntactic though, the two "paths" do different things that get to the same result.
Hopefully this answer offers an explanation rather merely invoking voodoo.
I am new to Ruby, and I am currently working with an API which is unfamiliar to me. In order to use code completion, which helps me learn, I installed RadRails in Eclipse. However, I am having trouble with Content Assist: specifically, the Content Assist does not reveal the methods for objects in the API.
For example, one of my objects, ins, represents a loaded XBRL instance document. If I run ins.methods, the list contains all of the methods I want, including those in the API (such as functions that allow me to access items in the instance):
...
item
item_all
item_all_groupby_vocab
item_all_map
item_by_vocab
item_ctx_filter
...
etc.
However, if I just type ins. with Content Assist enabled, it only shows options like:
dclone
gem
gem_original_require
JSON
Pathname(path)
...
etc.
which appear to be system options. As a result, the Content Assist exposes exactly zero of the methods I actually want to use. If I know the methods ahead of time and start typing them, I can get Content Assist to give them to me, eventually, by pressing Ctrl+Space. However, that requires me to know what I want ahead of time; since I am using this to explore the API, that doesn't work for me.
Does anyone know how to get RadRails/Eclipse to show me the correct methods?
Regards,
Matt
This is a general problem inherent to dynamic languages and IDEs/editors. The IDE has to guess at the type of the variable that the code assist is being invoked upon, and from that generate the list of applicable methods.
IRB has type information at runtime, so it knows what methods apply. The IDE is trying to guess the type by analyzing your code statically (not running it).
Having said that, the IDE should often be able to guess correctly. Providing the larger context of the snippet of code that this is being invoked on would be helpful to look into whether or not we could provide helpful content assist on this object. You may want to file a ticket with the version number, and the sample code here: http://aptana.com/r/apbugs
I was just wondering if there was a tool like this that existed, or something within Visual Studio 2010 that I just haven't come across before. I have a situation that arises that I'm sure many other people have ran into before. I debug into a method one time, and it works, another time, and it fails. I know (on the front end), what needs to happen for it to fail, and what needs to happen for it to pass, however I can't seem to find anything on the back-end that would show me the differences in all the properties that get passed through that method for each use case.
Is there a tool that can kind of analyze the objects in the code that I am passing through this method through each run, and then show me a diff of properties? Which ones are set/aren't set, which ones are different, etc.?
I normally wouldn't mind just blowing up the watches on each monitor and cruising through them, but we have a LOT of properties on these specific objects.
Thanks guys.
Would something like Mole 2010 work? I know you can basically do a diff on objects to compare their properties, but I'm not sure if this would work in your situation with method parameters.
Maybe Pex will help you? It analyzes your code and created input values based on identified code paths and boundary cases.
Is it possible to search or filter intellisense in visual studio?
Basically i know there is an enum in the project that contains 'column', but the enum doesnt begin with 'c'.
There has been lots of times where id rather not scroll through the hundreds (if not thousands) of valid objects it gives me.
I wonder if the real answer here is (and I won't be surprised to be voted down for this) that your enum isn't properly named. If it was then I'd expect the name to be obvious in the use context, may be consider renaming the enum?
You can search in Class View. Type "column" and hit enter.
Visual Studio 2010 changes all of this, giving you multiple very easy ways to do this type of search quickly.
If you're using ReSharper, you can use "Go To Symbol..." and type "column", and it will give you all symbols (types, properties, fields, methods, etc) that match.
Otherwise your best bet is to use the Object Browser and search.
I really don't know about doing that in intellisense itself, but assuming the objective is to actually find a member whose name you don't remember, you can write a small utility for that purpose using the underlying mechanism intellisense uses, reflection.
Open the Object Browser under View menu. From there, you can search within all the language constructs available to you.