The global VB6 error handler product referred to in the following link claims to "install a small callback hook into the VBE6 debugger":
http://www.everythingaccess.com/simplyvba/globalerrorhandler/howitworks.htm
I would like to implement this product myself because I would like more control over what it is doing. How is the above product likely to be achieving what it does?
The product you are looking at is a COM component. From the documentation that is available on the web site, it sounds like the COM component implements particular component classes. The first thing to do, if you already have the product, would be to fire up SysInternals procmon, run regsvr32 on the DLL, and figure out what component classes are implemented from the registry entries that are created. Once you know this, MSDN may be able to tell you what interfaces correspond to those component classes.
Microsoft developed a framework called Active Scripting that allows you to host a script engine and inject debugging capabilities. If one assumes that VB6 produces an exe that ties into that framework, you might be able to do:
Create a COM component that implements IApplicationDebugger
Implement IApplicationDebugger::onHandleBreakPoint to be able to respond to errors in the VB code
Read MSDN KB Q222966 to find out how to call back to VB from onHandleBreakPoint
It looks like the product injects the ErrEx class using IActiveScript::AddNamedItem. To provide the same behaviour, Implement IActiveScriptSite::GetItemInfo on the same COM component to return a pointer to an instance of (and the associated TypeInfo for) a COM component that implements the same interface as ErrEx. In your implementation of ErrEx.EnableGlobalErrorHandler you would do the following:
CoCreateInstance inproc Process Debug Manager
Cast reference to IRemoteDebugApplication
Register an instance of your IApplicationDebugger component using IRemoteDebugApplication::ConnectDebugger
I glossed over calling IActiveScript::AddNamedItem because I have no idea how you get a pointer to IActiveScript from a running process. Also, I don't know if creating a new instance of the Process Debug Manager will work, or if you somehow have to hook into an existing instance.
I apologize for the confusing explanation, missing information, and glossing over large parts of the process, but this is going waaay back...
You will want to read the Active Scripting APIs article at MSDN.
Related
I have read the two other questions on SO regarding this and I wanted to know if there is a good solution for that now / best practice.
Long story short, we use an SDK which is written natively and we've wrapped it so that it works on Xamarin.Android and Xamarin.iOS. It has asynchronous callback methods. I need to call a method in the shared code when a callback is received in the Android project for instance.
There's a lot of info for doing the opposite - using DependencyService. How about in my scenario? Does anyone have experience with an app like this and what's the best approach to keep code clean and do this using MVVM?
The options I know are:
Using a static App instance - this is what we currently do.
MessagingCenter
Anything else?
Actually I've never seen anyone recommend usage of MessagingCenter for anything else than communication between ViewModels so I am not sure it is recommended here. Also, I need to know the sender object type so I need a reference to the class in the platform specific project.
I would recommend you to use messagingCenter to pass data or call method between shared project and platform project. You can just send a new object instead of the class in the platform specific project.
Also, have a look at using eventhandler as I mentioned in this answer may help someone who want to call from the shared project into the platform specific one.
BTW, I mean you can even pass an object as TSender if it is not necessary to use:
MessagingCenter.Send<Object>(new object(), "Hi");
MessagingCenter.Subscribe<Object>(new object(), "Hi", (sender) =>
{
// Do something whenever the "Hi" message is received
});
I have no idea what COM is, just only need to use few methods via COM.
But is there any COM browser that will show methods inside gicen interface? By name or GUID or something.
Does COM stores soem metadata like comments to interfaces etc?
Interfaces defined in a type library (.tlb file, which can be embedded in a DLL) are described in it (the OLE/COM object viewer can show them), but hardly documented in it.
Others are only defined in the Windows headers (or in a third-party library's headers). To view the actual documentation, the best is to look it up on MSDN (or just Google the interface name, which works most of the time).
I have a Web Service like ServiceA.asmx. What is the right way to consume it?
I have two ways to consume a service:
1)adding Service Refernce:
I have added Service Refernce of ServiceA.asmx ( Like in http://microsoftfeed.com/2011/part-14-how-to-consume-a-web-service-in-windows-phone-7) and i am able to call the Functions in Service like in the link i have given. If we use this way there is no need to parse the Result, Result returned in Objects(easy to use).
2)Hitting the URL and Calling asynchronously:
Here we can hit the URL, that function will call the asynchronous function that asynchronous function will return the response. But here response will be in XML here we have to parse that XML in to an Object.(not easy if any Big XML is there)
Please Guide me on this
Personally I would use the 'Add service reference' option. It's easy to use, and this option is added to Visual Studio especially for consuming web services. You can still use MVVM to build up your models/viewmodels.
I don't have the option to check it right now, but from my head the classes generated when adding the service reference also implement INotifyPropertyChanged. So you could probably use the object directly (if they are in the structure as you want to use it.) as your Model. Based on that model you can create your own ViewModel which you can bind to the UI.
To see how this works have a look at the code samples on MSDN:
Implementing the Model-View-ViewModel Pattern in a Windows Phone Application
Weather Forecast Sample
Like the title says, i want to disable images, and ActiveX Controls in the vb6 webbrowser control using DLCTL_NO_RUNACTIVEXCTLS and DLCTL_NO_DLACTIVEXCTLS
Microsoft talk about it here: http://msdn.microsoft.com/en-us/library/aa741313.aspx
But i dont see any way to access IDispatch::Invoke from the vb6 application.
Any help would be greatly appreciated.
I do not think VB6 let you to add the ambient properties. Try host the ActiveX in another container (e.g. an ActiveX host written by yourself - but I do not know how much time you want to invest to declare VB-friendly OLE interfaces and implement them - or use another ActiveX like the one at http://www.codeproject.com/KB/atl/vbmhwb.aspx instead.
You don't access IDispatch::Invoke in VB6, you just write you method and IDispatch is automagically implemented.
Public Function DlControl() As Long
DlControl = DLCTL_NO_DLACTIVEXCTLS Or ...
End FUnction
Then just open Tools->Procedure Attributes and for DlControl function open Advanced and assign Procedure ID to -5512 (DISPID_AMBIENT_DLCONTROL). That's first part.
Second part is to set the client site to you custom implementation of IOleClientSite. You'll need a custom typelib, try Edanmo's OLELIB for declaration of these interfaces.
Here is a delphi sample how to hook your implementation of IOleClientSite. Apparently you'll alse have to call OnAmbientPropertyChange at some point.
In my context I have Navision involved, but perhaps this is related to every COM interop scenario, I don't know.
Anyway, the situation:
- I've a simple C# component registered for COM Interop
- I call it from Navision, just before inserting a new record (for who knows Navision, inside an 'OnInsert' trigger, thus in the context of a transaction)
I was expecting to have an ambient transaction, but System.Transactions.Transaction.Current is null.
Am I missing something?
Are there particular techniques I should adopt to make the transaction flow into my interop component?
Are you trying to begin a transaction in NAV and then access that transaction using your COM object?
It sounds like the System.Transactions.Transaction.Current value is null because you haven't initialised a transaction in your COM object - can you post a code sample of it?
Although from your post it sounds like you're expecting the Transaction.Current value to refer to the transaction you have initiated in NAV and I don't think this is what will happen, or is even possible!
What is your COM object trying to do with the transaction? Perhaps there is a different approach we could take?
Talking with Navision: Exposing .NET Components to Navision
How to: Use the BYOT (Bring Your Own Transaction) Feature of COM+
How to use COM+ transactions in a Visual C# component (MS KB 816141)