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Hi,
I have a base class A. I subclass A to create B, and add some properties to B. I need to know in A, when any of the properties in B have changed, without having to implement code in B's set methods. B will be created and maintained by my customers, I will only provide A for them to extend. I will never have access to modify the code for B which is what they will be creating.
What I'm looking for is some kind of global/system event in .Net that will notify the base class A that B's properties have changed.
Any help will be greatly appreciated!
tx,
Gideon
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Go for containment class. That may the best choice for you.
Sreejith Nair
[ My Articles ]
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I think you are familier with inheritance. See here we can go for two type of inheritance relation.IS-A and HAS-A. IS-A relation is our normal classical inheritance.And HAS-A relation is called Containment type of relation. Here relation means from base to derived.
Simply put; if a class contain another class defanision. So here we have total two classes and one contain the other. Suppose if you try to access the contained class from somewhere say some other class, it won't allow u to do that. And one more thing is there suppose if container class want to access the contained class.Here the container class need to declare a private contained class type.
I know it is not sufficient for you.But time not allowing me to do that. Better try to search for 'Has-A' relation or containement in popular search engins.
If you are not getting any stuffs after searching then please let me know that.;)
Sreejith Nair
[ My Articles ]
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Hi all!
I have a DataGrid that displays a table with 3 columns: ID, Name, Active.
Active is a checkbox. How can I achive, that first 2 columns are NOT
editable, but the last one is.
Thanks for the answers,
Jani
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DataGridColumnStyle.ReadOnly Property
Gets or sets a value indicating whether the data in the column can be edited.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemWindowsFormsDataGridColumnStyleClassReadOnlyTopic.asp
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isn't there a property called 'enable' or something like that for the grid. Basically u want the first two columns read only? i'm pretty sure that u can set that in the grid's property.
*HyVong*
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Hi,
My windows form app shows the main form by instantiating the form, then calling ShowDialog. If I display a msgbox in the form.load or form.activated event, the form closes itself. There must be more to it than that, since this did not always happen, but at this point in the project if I comment out the msgbox, the main form comes up fine, and if I leave the msgbox in, the form closes itself.
Any ideas what could be going on here?
Thanks
David
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Hello,
I have a problem with Key-Events on Forms in connection with hitting
the AcceptButton.
Situation:
- MdiChildForm 1 with DataGrid for selecting records. This DataGrid
has AllowNavigation false, ReadOnly true and all the textBoxes of all
the DataGridTextColumns are disabled, too.
The KeyUp-Event of this DataGrid is bound to a method that opens a
second form for editing that selected record when the Enter-key
(KeyValue 13) is used.
- EditForm 2 has Button btnOK for saving the data and closing the
form. The MdiParent of this form is the same as 1's. The AcceptButton
property is set to btnOK.
Hitting Enter in form 2 closes it (ok, that's what I want) and the
next thing happening is the KeyUp-Event in form 1 and hello ... here
is form 2 again (what is absolutely not wanted). There are neither
KeyDown, KeyPress or KeyUp occuring on form 2 before it closes and no
KeyDown or KeyPress on form 1.
How can I get a useful behaviour? Any hints are appreciated.
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Insted of click. Go for double click and write your code in double click event handler. I mean what ever code you are writing inside click event handler, put it as double click event handler.
Sreejith Nair
[ My Articles ]
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Hi
I'm trying to install MobileIT (Mobile Internet Toolkit). But I got a error because I have a "incompatible" version of .NET Framework, actually I have the versions:
.NET v1.0.3705 <-- First version that I had it
.NET v1.1.4322 <-- I think this is default
.NET v2.0.40607 <-- Beta installed from C# Express 2005
How could I fix this??
Thanks 
----
hxxbin
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i found the following 2 questions in one of the question banks but can't seem to find an answer. Can anyone please help.
Thanks.
Questions -
1)In C#, what are the trade-offs that you should consider between interfaces
and inheritance when designing for polymorphic behavior?
2)What are the advantages and disadvantages of streaming APIs like SAX, and
ADO.NET’s Datareader vs non streaming APIs like the XML DOM and the ADO.NET
Dataset?
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All I can say for 1, is that you can only inherit from one type, so if there is a posibility that you may want to inherit from a particular type, use an interface instead.
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I use .net remoting to transfer my own object to remote computer. But my own object contains some .net built in object like Font, Brush...etc. These built in object seems can't serialize itself, so I got an exception, how can I do to slove this problem? thanks in advance.
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Create another object that contains information on the brushes and fonts, and serialize that.
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Please check whether you gave proper serializable attribute for your custom class. Otherwise please mention the exception that you got when you tried this.
Sreejith Nair
[ My Articles ]
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Suppose I am selecting an item from a list box and I would like to change the all the menu's in another list box
For example, In a list box1 (Title- Country) if i selct India, correspondingly how will I get Cities of indian country in List Box2 (Title-City)
How to do it using C++, I am working in .Net Framework
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Here i can see your real requirement.
In Asp.net controls have AutoPostback property. BY default it will be false. Set it true if you are going for thin client application.
And if you want to achive this in thick client (i mean windows) Go for listbox item change event and write proper binding code in event defanision and event handler.
Sreejith Nair
[ My Articles ]
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Suppose I am selecting an item from a list box and I would like to change the all the menu's in another list box
For example, In a list box1 (Title- Country) if i selct India, correspondingly how will I get Cities of indian country in List Box2 (Title-City)
How to do it using C++, I am working in .Net Framework
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Add an event handler for the ComboBoxes SelectedIndexChanged event.
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I want 2 embed my visual basic modules and classes made in VB.Net to my newly built C# application.
How can i do it.
IT Bug
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You can create a solution with two projects. One project contains the C# code, and the other contains the VB.NET code. You can then reference the VB.NET in the C# project (right-click the project in the solution explorer and select Add References...)
You can now access your VB.NET code in the C# code. Remember to put using {Name Of Namespace}; if the VB.NET code is in a different namespace.
Does this help?
Do you want to know more?
Not getting the response you want from a question asked in an online forum: How to Ask Questions the Smart Way!
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Thanx Buddy!
It works well but i just had a query in mind if we can some how embed the code in the same project.
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Same solution: Yes, I am currently working on a solution with some parts written in VB.NET and some parts written in C#. They integrate very well.
Same project: No, you cannot mix code from different languages in the one visual studio project.
Do you want to know more?
Not getting the response you want from a question asked in an online forum: How to Ask Questions the Smart Way!
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Hi all,
I want to load a .Net Assembly in my Application, which is not located in the start folder of my App.
The Assembly-DLL I want to load is not shared and not registered in the GAC of the computer.
Does anybody knows a way how to load it!
I have heard ther is a way to add a search path for the assembly in the App.config file.
But I do not know thw respectin XML syntax.
Need Help
Thanks
Thomas
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System.Reflection.Assembly a = System.Reflection.Assembly.LoadFile("myassembly.dll");
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