Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Dependency Property vs Attached Property - WPF

Posted on 2011-03-10
3
Medium Priority
?
826 Views
Last Modified: 2012-06-21
Hi,

I have the following statement:

Attached properties differ from normal dependency properties in that they are not wrapped in CLR properties (i.e. standard .NET properties).

Dependency Properties Example:

<Canvas>
                   <Rectangle Height="72" Width="131" Canvas.Left="74" Canvas.Top="77" />
</Canvas>

Attached Properties Example:

<DockPanel>
      <Button x:Name="Button1" DockPanel.Dock="Left" />
</DockPanel>

Can you please let me know what is the difference between these two ? It looks like both are same but i am missing something !

Thanks
0
Comment
Question by:milani_lucie
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 23

Expert Comment

by:wdosanjos
ID: 35099531
The basic difference is that Attached Properties are dependency properties defined in a parent control and attached to a child control.  In your sample Canvas.Left is a property of Canvas, but it's attached to Rectangle.

More here:

Dependency Properties Overview
http://msdn.microsoft.com/en-us/library/ms752914.aspx

Attached Properties Overview
http://msdn.microsoft.com/en-us/library/ms749011.aspx
0
 

Author Comment

by:milani_lucie
ID: 35099717
wdosanjos:

Can you please define in simple terms:

What are Attched Properties ? What are Dependency Properties ? As per your definition, Attached Properties are nothing but Dependency Properties but attached to child controls. Am i correct ?

Can be Dependency Properties exist without attaching to child controls ?

Thanks
0
 
LVL 23

Accepted Solution

by:
wdosanjos earned 2000 total points
ID: 35100758
Yes, that's correct. Attached Properties are Dependency Properties that have been attached to child controls.

In the example below, Name, Background, BorderBrush, and BorderThickness are Dependency Properties of Button, while DockPanel.Dock is an Attached Property.

<DockPanel>
<Button Name="mybutton" Background="Green" BorderBrush="Black" BorderThickness="1"
   DockPanel.Dock="Left">
  My Button
</Button>
</DockPanel>

Open in new window


Maybe if you see how that's is done in code, it will make more sense. If you were to create the above dock panel and button in code, it would be something like this:

DockPanel myDockPanel = new DockPanel();
Button myButton = new Button();

// Set Regular Dependency Properties
myButton.Name = "mybutton";
myButton.Content = "My Button";
myButton.Background = Brushes.Green;
myButton.BorderBrush = Brushes.Black;
myButton.BorderThickness = new Thickness(1.0);

// Add Button to DockPanel
myDockPanel.Children.Add(myCheckBox);

// Set Attached Dependency Property (through the parent on the child control)
DockPanel.SetDock(myButton, Dock.Left);

Open in new window


I hope this helps to clarify.
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: jpaulino
XML Literals are a great way to handle XML files and the community doesn’t use it as much as it should.  An XML Literal is like a String (http://msdn.microsoft.com/en-us/library/system.string.aspx) Literal, only instead of starting and ending with w…
A while ago, I was working on a Windows Forms application and I needed a special label control with reflection (glass) effect to show some titles in a stylish way. I've always enjoyed working with graphics, but it's never too clever to re-invent …
This course is ideal for IT System Administrators working with VMware vSphere and its associated products in their company infrastructure. This course teaches you how to install and maintain this virtualization technology to store data, prevent vuln…
In this video you will find out how to export Office 365 mailboxes using the built in eDiscovery tool. Bear in mind that although this method might be useful in some cases, using PST files as Office 365 backup is troublesome in a long run (more on t…
Suggested Courses

721 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question