 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
.NET Forum / Windows Forms / WinForm General / March 2006Kind of event overriding
I have an object that works with an external treeview (myObject.TreeView = formTreeView) On myObject.TreeView = formTreeView assigment an AftreSelect event is being attached inside the object code. The problem is that formTreeView may have its AfterSelect event that will be executed before myObject AtferSelect when I want it to be executed after. But how to do it? MH >I have an object that works with an external treeview > (myObject.TreeView = formTreeView) [quoted text clipped - 5 lines] > > But how to do it? You can't. The whole point of events as compared to public delegates is that you can't mess with them from outside the class. If this wasn't the case you would have a massive security hole. You'll have to rethink your design - possibly derive your own class from TreeView and create a new event to fire first. > You can't. I must say this is a major overlook on a part of M$. > The whole point of events as compared to public delegates is that you > can't mess with them from outside the class. If this wasn't the case > you would have a massive security hole. I don't agree with a such approach. Either I'm in control or I'm being controled by some stupid rules. > possibly derive your own class from TreeView The best way to get into a mess. MH >> You can't. > > I must say this is a major overlook on a part of M$. I don't think that you will find anyone to agree with you. >> The whole point of events as compared to public delegates is that you >> can't mess with them from outside the class. If this wasn't the case >> you would have a massive security hole. > > I don't agree with a such approach. > Either I'm in control or I'm being controled by some stupid rules. You are in control of YOUR classes - why should you have control over someone else's class that they don't want to give you? As I said it is POSSIBLE to use a public multicast delegate (either as a field or a property) instead of an event. In this case the user of your class could add,remove or rearrange the order of delegate invocation at will. >> possibly derive your own class from TreeView > > The best way to get into a mess. No - it's quite straightforward: all events in the framework are fired from virtual methods called "On..." . You just need to override the appropriate method and raise your own event before calling the base implementation to raise the original event. > I don't think that you will find anyone to agree with you. Well, in such case M$ went mad when they made the KeyPress event public. Can you imagine the mess one can create in an application when a user types for example FCUK as a company name? MH Marius, This is not overlook at all. This is the way this design patern is defined and has to work.  SignatureStoitcho Goutsev (100) >> You can't. > [quoted text clipped - 12 lines] > > MH > This is not overlook at all. This is the way this design patern is > defined and has to work. Yes, yes, The Big Brother knows better what I want. MH >> This is not overlook at all. This is the way this design patern is >> defined and has to work. > > Yes, yes, The Big Brother knows better what I want. No - the big brother knows better what MOST people using C# want and security comes high on the list. BB neither knows nor cares what you as an individual want especially as, according to your email address, your are nobody :-) > No - the big brother knows better what MOST people using C# want and > security comes high on the list. There is no such thing as "security" for developers (just for end users), this is just a tool limitation. If a developer wants to do something he/she should be able to do it. Remember, those stupid computers are here to serve people. Security? Which system do you prefer when crossing a road? German, where can cross a road only in selected places and you have to wait for a green light or face penalty or UK, where you can cross a road at any place and time, but watch the traffic before crossing. Most of the progress was made by people who took a risk (even when they had to break a rule or two). MH nobody@con.eu -> EU is one big con and due to stupid rules sooner or later everyone will be "nobody" in EU. EU rules will control your life (using computers and M$ software) >> No - the big brother knows better what MOST people using C# want and >> security comes high on the list. > > There is no such thing as "security" for developers (just for end > users), this is just a tool limitation. Developers are also users of other developers libraries. > If a developer wants to do something he/she should be able to do it. > Remember, those stupid computers are here to serve people. You can do something stupid. But why do you expect MS ti help you? They are busy enough doing their own stupid things :-) > Security? Which system do you prefer when crossing a road? > [quoted text clipped - 5 lines] > UK, where you can cross a road at any place and time, but watch the > traffic before crossing. The analogy is not a good one - in neither case is your security enforced in the same sense as we are talking about - they penalize breach of rules rather than make it impossible - A better analogy would be a pedestrian footbridge with no access to the road at all. > Most of the progress was made by people who took a risk (even when they > had to break a rule or two). We are not talking about rules here - If it was just a rule then you would have just broken it and not posted a question. If you want to take risks then write in C++ not C#. > MH > > nobody@con.eu -> EU is one big con and due to stupid rules sooner or > later everyone will be "nobody" in EU. EU rules will control your life > (using computers and M$ software) I can't argue with that :-( P.S. We are in the wrong group here anyway - it should be the csharp one. > If a developer wants to do something he/she should be able to do it. If you want it you should go ahead and implement it. The framework and the languages gives you everything to do it. SignatureStoitcho Goutsev (100) Marius, You can't control the order of event processing. The idea behind this design pattern is that you don't care and basically don't know how many listeners you have, thus you don't care about the order of execution. There are different design patterns such us "Chain of Responsibility" where you can guarantee the order of execution. SignatureHTH Stoitcho Goutsev (100) >I have an object that works with an external treeview > (myObject.TreeView = formTreeView) [quoted text clipped - 7 lines] > > MH Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.