Ccomptr idispatch queryinterface sample

Anyway, i was reading his blog and came across this post. How to use queryinterface to get html source of a web page. This sample uses the following steps to export the barcode image. Ccomptr wraps any interface pointer and will call addref and release properly. There are cases for queryinterface method in msdn one amoung them is, a call to queryinterface for a pointer to a specified interface succeeds the first time, it must succeed again, and if it fails the first time, it must fail on all. Solution you can reliably use iacadstate to check whether the autocad is free to process automation calls.

It correctly checks to make sure that the pointer isnt null before trying to convert the idispatch pointer to an irequest pointer. Ccomptr provides a specialization for idispatch that enables it to store pointers to com automation components and invoke the methods on the interface by using late binding. Internally constructor will call piunknown queryinterface to fetch interface pointer according to the iid. Instead you can use windows api functionality to find information about that. I did change the declaration to ccomptr from ccomptr because i couldnt figure out how to convert between the two afterward. The hresult returned from spselectionitem doesnt fail and mailptr2 is set now, however i run into issues when calling mailptr2s methods. Both are derived from ccomptrbase, and both do automatic reference counting the ccomptr and ccomqiptr classes can help eliminate memory leaks by performing automatic reference counting. Application and id like to cast this idispatch to native documentwindow in order to. It also shows how to traverse the featuremanager design tree, get a component, and suppress and resolve that component. Why might i be getting this error, and what can i do to prevent it. Thanks pete, good to know theyre good for something. Well the best way is to get your idispatch interface directly with its clsid. Integrate zellowork into your windows app or build a custom radio gateway zellopttzellowork windowsclientsdk.

Ccomdispatchdriver is a typedef for ccomqiptr queryinterface to fetch interface. That is, you dont need to worry about the life cycle of your com interface pointer. Ccomptr and releasing com objects manufacturing devblog. Ucancode software focuses on general application software development. In each case, the code repeated a loop times, and inside the loop, the code did a number of getsetinvoke operations on an html document. Notice that in the idl fragment, the syntax seems more standard.

Application and id like to cast this idispatch to native documentwindow in order to call its methods and properties not via idispatchinvoke, but directly. This means that you can choose to handle only certain events and ignore others. The screen scraping selection can be a rectangular area or a point, with some additional features. I have a dual idispatch interface of documentwindow class, related to powerpoint. Calls queryinterface to retrieve the iunknown pointer. Ideally i would like to do this using smart com pointers ccomptr. How to cast dual interfaces of microsoft powerpoint classes.

Why would i somtimes get access is denied when requesting. Stack overflow for teams is a private, secure spot for you and your coworkers to find and share information. If you get this working then let me know and there are a few optimizations that can be made to take advantage of protocol extension. Now instead of deriving from iunknown, the isum interface derives from idispatch, which is itself derived from iunknown, so we still get the queryinterface, addref, and release methods added to the vtable.

Ccomptr provides a specialization for idispatch that enables it to store pointers to com automation components and invoke the methods on the interface. An interface based solely on idispatch is called a dispinterface. When developing applications that embed the ie webbrowser control as an application rendering engine or when developing browser debugging tools, the crossdomain scripting restrictions in the browser can limit the effectiveness of developing those solutions. I have create a test project vs2008 with a drawing inside. Feb 22, 2006 construct a new ccomptr object with an iunknown pointer and an iid, which represents the interface you are interested in.

In this case you should just delete this entry and inheritance from idispatchimpl. Below is some sample code used to get the dispatch id. By adam nagy when using com objects like the ones provided by the inventor com api, then you have to take care of releasing the references to the objects you retrieved. Jan 22, 2011 i have code triggered inside a documentcomplete listener that attempts to get the dispatch id from the script engine. Tech support scams are an industrywide issue where scammers trick you into paying for unnecessary technical support services.

An example invoke implementation that checks the state and prints part of the. Dec 09, 2009 you also mentioned that the queryinterface in button 3 code returns null. Com may have given you a proxy to the underlying object, which means that the pointer has nothing to do with idispatch likewise, an implementation may wrap an object that implements idispatch and when you call queryinterface it delegates to this object. In this case we want to work with idispatch, which is a dynamic interface that lets us figure out which methods to call at runtime. However, it seems that sometimes smart pointers are too smart in particular, im referring to the secret queryinterfaceing assignment operator discussed by jared parsons on his blog. The following example shows how to use ccomptr to instantiate a com object and obtain. Feb 27, 2019 this is my generic class with templates when i try to query using queryinterface. No, you should always you queryinterface just because youve com an iunknown interface it doesnt mean you can directly cast it to idispatch. That is, you can use an instance of a smart pointer class in many of the places you normally use a pointer.

Stdmethodimp invokedispid dispidmember, refiid riid, lcid lcid, word wflags, dispparams pdispparams, variant pvarresult, excepinfo pexcepinfo, uint puargerr. Create morovia barcode activex object ccomptr spdisp. In this sample well use the queryinterface function could use ccomqiptr as well and itypeinfo to. This is the interface to use for most embedding scenarios. Queryinterface for iretrieveapplication and use setapplicationobject to pass in the idispatch of the acad app. Ccomdispatchdriver is a typedef for ccomqiptr, which is implicitly convertible to ccomptr. However, i cant seem to figure out how to capture the returned object reference effectively and pass back an idispatch pointer to the host application.

I have code triggered inside a documentcomplete listener that attempts to get the dispatch id from the script engine. If you get this working then let me know and there are a few optimizations that can be. You can receive events from windows media player in two ways. No matter you want to develop a simple database workflow application, or an large flowdiagram based system, our product will provide a complete solution for you. Queryinterface is called in vb when it needs to verify that the object is indeed an ole automation object i. How to cast dual interfaces of microsoft powerpoint. By vladimir ananyev issue how to get the reference key from an occurrence in an assembly and later get back the occurrence from the reference key. By xiaodong liang issue how do i check the idle status of autocad using ole automation functions. By adam nagy in case of geometry objects you do not have the typeobjecttype properties that you could check the type with. Hi i want to manipulate html table using ihtmltable com interface. But if you want to do that you can use queryinterface to get idispatch pointer but that. Im working on core clr host integration code, where i create a runtime host and then pass back a.

When the ccomptr instance goes out of scope, the destructor calls release on the underlying pointer. Create and use ccomptr and ccomqiptr instances github. Please help me out by giving a small code example whicn gives me idea of qi and getting ihtmldocument2 and using this to get source of the page. The derived classes add their own constructors and operators, but rely on the methods provided by ccomptrbase requirements. You can help protect yourself from scammers by verifying that the contact is a microsoft agent or microsoft employee and that the phone number is an official microsoft global customer service number.

The derived classes add their own constructors and operators, but rely on the methods provided by ccomptrbase. Pete warden left a comment on my blog that hes porting a firefox extension to ie and that he appreciates the articles i wrote about ie addon development. However, the second version may be less errorprone because it uses. Com may have given you a proxy to the underlying object, which means that the pointer has nothing to do with idispatch.

You use different idl attributes depending on whether you are implementing a pure idispatch interface or a dual interface. This is what ccomptr is helping you with, which is a smartpointer and provides auto release of objects. Tselection was created to enable the user to invoke a screen object selection ui and get the selected area in a controlled way. Ccomptr is a convenient smart pointer atl class to manage reference counting of com objects. Com programming idispatch, queryinterface, cocreateinstance, iunknown, gettickcount, itoa, atl control. You are getting an idispatch, then effectively downcasting it to ihtmldocument2. Atl does provide a com smart pointer class named ccomqiptr, but it uses some atlspecific funtions inside so that it can not be used outside the atl environment. Constructs a new ccomptr object with an iunknown pointer and an iid. There is a chance that applytransform invoked correctly and ju.

Atl uses ccomptr and ccomqiptr to manage com interface pointers. After that, this new ccomptr object can be used as an interface pointer itself. Intermittently, the request for the dispatch id will fail with access is denied. Despite i do not see any errors in your code you may try the following. Accessing the ihtmldocument interface of an html frame. Nov 19, 2019 ccomptr provides a specialization for idispatch that enables it to store pointers to com automation components and invoke the methods on the interface by using late binding. The problem here is that if the idispatch is null then the hr is never set by the line that fetches the irequest pointer.

Hi this is my generic class with templates when i try to query using queryinterface here the spdispatch is always null this doesnt work in vs2017 with windows server 2016 please help in resolving this, tlb is compiled with midl in vs2017 no difference though this works fine with vs2015 and. I wont post that code here, but if youre really interested in it, you can see it in the full sample. If you have a ccomptr pco1, you dont call pco1isequalobjectpco2 because this invokes the operator defined in the ccomptr class which returns an automatically addrefd version of the underlying com interface so that you can dereference it. A smart pointer is an object that behaves like a pointer. The following functions both do the same logical operations. To test the code load the addin, invoke showpmp and select the edge in the section view of the drawing. Contribute to mmoreartydispatchptr development by creating an account on github. Using atl vs2008 how can i enumerate the available methods available on a given idispatch interface idispatch. Internally, a constructor will call piunknown queryinterface to fetch the interface pointer according to. I need to search for a method with a specific name and, once i have the dispid, invoke the method i know the parameters the method takes.

Furthermore, is the object the queryinterface method of which is called implemented by you or by some other developer. Table manipulation using ihtmltable interface solutions. The vtable of a dispinterface is identical to that of idispatch itself. This class provides the basis for other smart pointers which use com memory management routines, such as ccomqiptr and ccomptr.

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