What is dependency property in C#?

Advertisements. In WPF applications, dependency property is a specific type of property which extends the CLR property. It takes the advantage of specific functionalities available in the WPF property system. A class which defines a dependency property must be inherited from the DependencyObject class.

A Dependency Property is a property whose value depends on the external sources, such as animation, data binding, styles, or visual tree inheritance. Not only this, but a Dependency Property also has the built-in feature of providing notification when the property has changed, data binding and styling.

Likewise, what is difference between dependency property and attached property? Attached properties are a type of dependency property. The difference is in how they’re used. With an attached property, the property is defined on a class that isn’t the same class for which it’s being used. This is usually used for layout.

Likewise, how does dependency property work internally?

To summarize,

  1. Dependency Property System holds a collection of all DependencyProperty with its corresponding ownerType.
  2. Each instance of a DependencyObject holds a collection of all individual DependencyProperty that has been changed either through animation or programmatically.

Why do we need dependency property in WPF?

Dependency properties are used when you want data binding in a UserControl , and is the standard method of data binding for the WPF Framework controls. DPs have slightly better binding performance, and everything is provided to you when inside a UserControl to implement them.

Where are dependency properties stored?

In contrast, dependency properties are not stored in local object. Dependency properties are stored in a dictionary of key/value pairs which is provided by the DependencyObject class. It also saves a lot of memory because it stores the property when changed. It can be bound in XAML as well.

Is dependency property static property?

In Button class many properties are Dependency Property like (Width, Hight) and it is static property.

What is INotifyPropertyChanged?

INotifyPropertyChanged is an interface member in System. ComponentModel Namespace. This interface is used to notify the Control that property value has changed. ComponentModel Namespace. This interface is used to notify the Control that the property value has changed.

How does dependency injection work C#?

Implementation of Dependency Injection Pattern in C# The Dependency Injection pattern uses a builder object to initialize objects and provide the required dependencies to the object means it allows you to “inject” a dependency from outside the class.

Why is dependency property static readonly?

Because it makes it obvious, that the value of this property cannot be changed after initialization. Static and readonly because this isn’t a definition that should ever change; the property system needs to get consistent results. In the attached property case, you want there to be an “owner” class.

What is a dependency object?

Dependency object is the base object for all WPF objects. All the UI Elements like Buttons TextBox etc and the Content Elements like Paragraph, Italic, Span etc all are derived from Dependency Object. Dependency objects are used for WPF property system.

What is dependency property in WPF interview?

A dependency property is a property that is backed by the WPF property system instead of by a field in the declaring class. The significance of this is that, because WPF owns the property, WPF can factor in various considerations when calculating the property value — such as animations, styles and data bindings.

What is attached property?

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”.

Why is dependency property static?

DependencyProperty has to be static (Class level) because when we create multiple objects of the class which has that property and want to refer the default value for that property the value has to come from that static instance of DependencyProperty.

What is CLR property?

CLR property is just a wrapper around private variables. It uses Get / Set methods to retrieve and store value of a variable into it. A CLR property gives you only one block in which you can write code to invoke whenever a property is get or set.

What are attached properties in WPF?

Attached properties are properties which can be set on any wpf object (basically, at least a DependencyObject) via the DependencyObject. SetValue method. The purpose for this mechanism is to “attach” to other objects information needed by parent objects, not the child objects themselves. For example, the Grid.

What is trigger in WPF?

WPF – Triggers. Advertisements. A trigger basically enables you to change property values or take actions based on the value of a property. So, it allows you to dynamically change the appearance and/or behavior of your control without having to create a new one.

What is dependency injection in WPF?

The basic idea is to have a dependency container that builds up a view. The view has a viewmodel injected, that is bound to the DataContext. The viewmodel concentrates and provides data and commands for the view that it gets from services, that are injected by the constructor.

What is CLR in WPF?

Windows Presentation Foundation (WPF) provides a set of services that can be used to extend the functionality of a common language runtime (CLR) property. A property that is backed by the WPF property system is known as a dependency property.