Question

What is WPF Dependency Property and how can we use?

Answer 1

WPF has provided some extended services to the CLR property that we can collectively call Dependency Properties. 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 builtin feature of providing notification when the property has changed, data binding and styling.

 

 

 

Advantages of a Dependency Property:

• Less memory consumption
• Property value inheritance
• Change notification and Data Bindings
• Participation in animation, styles and templates
• CallBacks
• Resources
• Overriding Metadata

Code

1. public class CarDependencyProperty: DependencyObject  
2. {  
3.     //Register Dependency Property  
4.     public static readonly DependencyProperty CarDependency = DependencyProperty.Register("MyProperty", typeof (string), typeof (DependencyPropertySample));  
5.     public string MyCar  
6.     {  
7.         get  
8.         {  
9.             return (string) GetValue(CarDependency);  
10.         }  
11.         set  
12.         {  
13.             SetValue(CarDependency, value);  
14.         }  
15.     }  
16. }  
17. public partial class CarDependencyPropertyDemo: Window  
18. {  
19.     public CarDependencyPropertyDemo()  
20.     {  
21.         InitializeComponent();  
22.     }  
23.     private void MyButton_Click(object sender, RoutedEventArgs e)  
24.     {  
25.         CarDependency dpSample = TryFindResource("CarDependency ") as CarDependency;  
26.         MessageBox.Show(dpSample.MyCar);  
27.     }  
28. }