WPF Interview Questions and answers Part 3

1.) What is tree concepts in WPF ?                                                                                          
 All elements of  a WPF UI (User Interface) are hierarchically related.The template of WPF contains two types of tree concepts.

1. Logical Tree
2. Visual Tree

2.) What is Logical tree in WPF ?                                                                                              

• Each Element that we explicitly add to window ,be it layout control or content will be part of the window's logical tree.This tree is the exact representation of what you have specified to be display. 
• The Logical Tree describes the relationship between elements of UI (user interface).

3.) What is Advantage of Logical tree in WPF ?                                                                   

There are some advantage of Logical tree as given below:-

• It inherit the dependency property values.
• It is used to binding the elements.
• It is used for forwarding the Routing events.
• It is helpful to resolve the dynamic resources.
• It is used as a root element in any template.

4.) What is Visual tree in WPF ?                                                                                              

• The Visual tree Contains all the rendering information needed to compose the output to a display device (computer).These are harder to visualize by looking at codes.
• The Visual tree contains all the Logical elements + Visual elements of the UI (Template) of each element.

5.) What is advantage Visual tree in WPF ?                                                                           
There are some advantage of visual tree in wpf.

1. It is helpful to rendering (displaying) the visual elements.
2. It contains number of additional UI element classes for each entry in the logical tree.
3. It propagate the IsEnabled Properties.
4. It propagate the ambiguity. 

6.) What is XBAP in WPF ?                                                                                                        
XAML Browser Applications (XBAPs) are a variant of WPF application which can run over the internet. XABPs will only run on windows.It requires .NET 3.0/3.5/4.0/4.5 Framework.
7.) What is core assemblies used in WPF ?                                                                           
There are three main assemblies used in wpf.

1. WindowsBase.dll
2. Presentationcore.dll
3. PresentationFoundation.dll

8.) What are two main Namespace classes used in WPF ?                                              

1. Application class
2. Windows class

More Details...

9.) What is a BAML in WPF ?                                                                                                      

• This is known as Binary Application Markup Language (BAML).
• It is a Binary representation of XAML.
• It is more efficient.  

10.) What is Data binding in WPF ?                                                                                          
Data binding is the process that establishes a connection between the application UI and business logic. A typical use of data binding is to place server or local configuration data into forms or other UI controls. In Windows Presentation Foundation, this concept is expanded to include the binding of a broad range of properties to a variety of data sources.