UserControl Inheritance

Question

Hi,

I have two UserControls
1.UserControl1
2.UserControl2

how to inherit Usercontrol1 in UserControl2.

Please give me some idea about this.

Regards,
Vijay

Answer 1

public class UserControl2 : UserControl1

{

}

 

I think this question is more related to the basics of object oriented programming and you should really refer to the appropriate forums or you simply didn't cover your issue within the question.

 

Answer 2

Hi Desnis Vuyka,

You are correct.In CS file you will do like this.

public class UserControl2 : UserControl1

{

}

But what about in Xaml.I did like this

In UserControl1.Xaml
<UserControl x:Class="MDIWindows.Parent"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Height="300" Width="300">

</UserControl>

In UserControl2.Xaml
<srcUserControl1 x:Class="MDIWindows.Child"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlnsrc="clr-namespace:MDIWindows"
    Height="300" Width="300">
 
</src:UserControl1>

Here i am getting error.
Please me about this.

Regards.

Answer 3

In current version of WPF, you cannot subclass from XAML generated classes, you need to do it in code instead something like the following should work:

Code Snippet

public class Parent : UserControl
{
}

<src:Parent x:Class="Test.Child"
                 xmlns:src="clr-namespace:Test"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"/>

Hope this helps

Answer 4

Dear all,

I have a question about all this: how to develop my controls for the moment ?

As inheritance with XAML generated classes does not work, i don't know whether I should programmatically declare all my "generic" controls in the base class, or abandon this idea of common controls and duplicate XAML declarations...

Actually the question could be: should I design my controls as if a future WPF release would support XAML base-classes, and wait for this next release with a temporary solution ?

What is your opinion about this ?

Answer 5

No answer... Is my question stupid? (don't hesitate...), and if yes: why?

Answer 6

3.5sp1 is the next release (just went to Beta).  It hasn't yet fixed this problem.

I'm unsure if the release after that will support it.

 

I recommend you plan to proceed without it for anywhere from 1 - 3 years...I can't promise when we will address...

 

Thanks, Rob

Rob Relyea | Program Manager, WPF & Xaml Language Team
robrelyea.com | /blog | /wpf | /xaml

Answer 7

Thanks much for your answer.
The most important is that you planned to fix the problem someday...

Answer 8

Just curious what are you trying to do in this case? Do you want the child control to have the exact same look as its parent but have different functionality? Or do you want to add additional controls to the child that weren't on the parent?

Answer 9

Go to ____.

Answer 10

I have done what you did in UserControl2.Xaml with some success.   You need to add a namespace where your UserControl1 is defined.  See below

<src:UserControl1 x:Class="MDIWindows.Child"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlnsrc="clr-namespace:MDIWindows"
    xmlns:srs="myNamespace"
    Height="300" Width="300">
 
</src:UserControl1>

This approach will compile and execute, but will not display correctly in the Visual Studio Designer.  I believe this is a bug.
Your Solution Build will succeed, even though you will get an error when you try to update the Designer window.

Answer 11

Check this out:
http://svetoslavsavov.blogspot.com/2009/09/user-control-inheritance-in-wpf.html