Full Answer
What are the attached properties in XAML?
May 19, 2020 · It's called an attached property cause they're attached with WPF elements and set by a DependencyObject.SetValue method. For example, here Grid.row is an attached property of a control Grid and it is applied on a Grid's children, which are Stackpanel, Button & Textblock in this example. The attached properties are seperated by a dot (.)
Why are attached properties called attached properties?
May 03, 2009 · WPF Tutorial | Attached Properties Attached Properties Introduction Attached properties are a special kind of DependencyProperties. They allow you to attach a value to an object that does not know anything about this value. A good example for this concept are layout panels. Each layout panel needs different data to align its child elements.
What are dependency properties in WPF?
Apr 19, 2020 · An attached property is intended to be used as a type of global property that is settable on any object. In Windows Presentation Foundation (WPF), attached properties are typically defined as a specialized form of dependency property that does not have the conventional property "wrapper".
Is it possible to have all the properties of a WPF control?
Feb 19, 2015 · APs are called “attached” properties because we can attach some behaviour to the control that is originally not expected from that control. One analogy that I can suggest here is that, what Extension Methods are to classes in C#, is …
What is an attached property in WPF?
An attached property is a Extensible Application Markup Language (XAML) concept. Attached properties enable extra property/value pairs to be set on any XAML element that derives from DependencyObject, even though the element doesn't define those extra properties in its object model.Feb 10, 2022
What is attached property and dependency property in WPF?
Attached properties allows container to create a property which can be used by any child UI elements whereas dependency property is associated with that particular elements and can help in notification of changes and reacting to that changes. Attached properties are basically meant for the container elements.May 8, 2013
What's an attached property?
Attached properties are a special kind of DependencyProperties. They allow you to attach a value to an object that does not know anything about this value. A good example for this concept are layout panels. Each layout panel needs different data to align its child elements.Aug 6, 2009
What is attached properties and how do you register it?
Attached properties are typically defined as a specialized form of dependency property that doesn't have a conventional property wrapper. Most attached properties for Windows Presentation Foundation (WPF) types are also implemented as dependency properties.Jan 6, 2022
What is attached dependency property?
Attached Properties (AP) are again a kind of Dependency Property (DP) in XAML. They can be used to receive a notification of a change of themself since they are a type of Dependency Property but one of the differences that these properties have is that they are not defined in the same class they used, unlike DPs.Feb 19, 2015
Why do we need dependency property in WPF?
The main reason to create DependencyProperty is when you write you own WPF control. DependencyProperties can be used as binding source and target, and can be animated. The properties of all framework's controls are implemented as DependencyProperty , that why you can make powerful data binding in XAML.Sep 3, 2013
Is a detached garage better than attached?
The Benefits of a Free-Standing Garage You might prefer a detached garage if your lot size is long and narrow, as this structure can be built behind the home to take advantage of the space. These garages are also considered safer, as carbon monoxide fumes won't be seeping into your home through the garage entry door.
What is the difference between single attached and single detached?
Single Attached means that a house shares a common wall typically on both sides of the property. A duplex can be considered as an attached one. It is composed of two dwellings in generally one structure. While on the other hand a Single Detached property stands alone and with extra spaces of lot around it.
What is single attached?
Single attached means one side of your house is built directly on the boundary of your lot. You share this boundary line with a neighbor, so you end up sharing a wall as well. In the Philippines, two adjoining single attached homes are referred to as a duplex.Jan 4, 2021
What is the meaning of WPF?
Windows Presentation FoundationWindows Presentation Foundation is a UI framework that creates desktop client applications. The WPF development platform supports a broad set of application development features, including an application model, resources, controls, graphics, layout, data binding, documents, and security. WPF is part of .Jan 28, 2022
Which class is used for data binding in WPF?
In WPF data binding is done using the DataContext property which is a dependency property (discussed here) of the framework element class. All the controls derived from the framework element class have this property which in turn can be used to bind data from the source.Feb 29, 2016
What is attached property in xamarin forms?
Attached properties enable an object to assign a value for a property that its own class doesn't define. For example, child elements can use attached properties to inform their parent element of how they are to be presented in the user interface.Jul 8, 2021
How to set value of attached property in XAML?
To set the value of an attached property, add an attribute in XAML with a prefix of the element that provides the attached property. To set the the Canvas.Top and Canvas.Left property of a button aligned within a Canvas panel, you write it like this:
What is attached property?
Attached properties are a special kind of DependencyProperties. They allow you to attach a value to an object that does not know anything about this value. A good example for this concept are layout panels. Each layout panel needs different data to align its child elements.
What is attached property in WPF?
Attached Properties are a feature provided by WPF. It allows us to declare an Attached Property in any class and attach it to a WPF element. It is comparable to an extension method in C# with the difference that it doesn’t extend something by a new functionality but instead adds new information. The probably most commonly used Attached Properties are Grid.Row and Grid.Column. Using these Attached Properties you can add row and column information to a WPF element which actually doesn’t know anything about rows and columns.
Does Tag add functionality to XAML?
However, it doesn’t add any new functionality. It only adds the new information ‘Tag’ to the XAML element. This is in contrast to Behaviors and Attached Behaviors which add functionality to a XAML element.
Prerequisites
This article assumes basic knowledge of the .NET type system and object-oriented programming. To follow the examples in this article, it helps to understand XAML and know how to write WPF applications. For more information, see Walkthrough: My first WPF desktop application.
Dependency properties and CLR properties
WPF properties are typically exposed as standard .NET properties. You might interact with these properties at a basic level and never know that they're implemented as a dependency property. However, familiarity with some or all of the features of the WPF property system, will help you take advantage of those features.
Dependency properties back CLR properties
Dependency properties and the WPF property system extend property functionality by providing a type that backs a property, as an alternative to the standard pattern of backing a property with a private field. The name of this type is DependencyProperty.
Property functionality provided by a dependency property
Unlike a property that's backed by a field, a dependency property extends the functionality of a property. Often, the added functionality represents or supports one of these features:
Dependency property value precedence
Any of the property-based inputs within the WPF property system can set the value of a dependency property. Dependency property value precedence exists so that the various scenarios for how properties obtain their values interact in a predictable way.
Prerequisites
- The article assumes a basic knowledge of dependency properties, and that you've read Dependency properties overview. To follow the examples in this article, it helps if you're familiar with XAML and know how to write Windows Presentation Foundation (WPF) applications.
Attached Properties in Xaml
- In XAML, you set attached properties by using the syntax <attached property provider type>.<property name>, where the attached property provider is the class that defines the attached property. The following example shows how a child element of DockPanel can set the DockPanel.Dockproperty value. The usage is similar to a static property in that you reference th…
Attached Property Usage Models
- Although any object can set an attached property value, that doesn't mean setting a value will produce a tangible result or the value will be used by another object. The main purpose of attached properties is to provide a way for objects from a wide variety of class hierarchies and logical relationships to report common information to the type that defines the attached propert…
Attached Properties in Code
- Attached properties in WPF don't have the typical CLR get and set wrapper methods because the properties might be set from outside of the CLR namespace. To permit a XAML processor to set those values when parsing XAML, the class that defines the attached property must implement dedicated accessor methods in the form of Get<property name> and Set<property name>. You c…
Attached Property Metadata
- Metadata for an attached property is generally no different than for a dependency property. When registering an attached property, use FrameworkPropertyMetadata to specify characteristics of the property, such as whether the property affects rendering or measurement. When you specify a default value by overriding attached property metadata, that value becomes the default for the i…
Custom Attached Properties
- When to create an attached property
Creating an attached property is useful when: 1. You need a property setting mechanism available to classes other than the defining class. A common scenario is for UI layout, for instance DockPanel.Dock, Panel.ZIndex, and Canvas.Topare all examples of existing layout properties. In … - How to create an attached property
If your class defines an attached property solely for use by other types, then your class doesn't need to derive from DependencyObject. Otherwise, follow the WPF model of having an attached property also be a dependency property, by deriving your class from DependencyObject. Define y…
Learn More
- For more information about creating an attached property, see Register an attached property.
- For more advanced usage scenarios for dependency properties and attached properties, see Custom dependency properties.
- You can register a property as both an attached property and a dependency property, and include conventional property wrappers. In this way, a property can be set on an element by u…
- For more information about creating an attached property, see Register an attached property.
- For more advanced usage scenarios for dependency properties and attached properties, see Custom dependency properties.
- You can register a property as both an attached property and a dependency property, and include conventional property wrappers. In this way, a property can be set on an element by using property wr...
See Also