Ask in All WPF Interview Visit for Important WPF Questions and Answers
www.code-sample.com/2013/08/wpf-interview-questions-and-answers.html
WPF stands for Windows Presentation Foundation. It is an
application programming Interface for developing rich UI on Windows. WPF is
introduced in .NET 3.0. By the use of WPF we can create two and three
dimensional graphics, animations etc.
What is XAML and how it is related
to WPF?
XAML is a new mark up language which is used for defining UI
elements and its relationships with other UI elements. The XAML is introduced
by WPF in .NET 3.0 WPF uses XAML for UI design.
Does XAML file compiled or Parsed?
By default XAML files are compiled, But we do have options
to let it be parsed.
What is the root namespace used for
Animations and 3D rendering in WPF?
System.Windows.Media namespace.
What are the names of main assemblies
used by WPF?
a)WindowsBase
b)PresentationCore
c)PresentationFoundation
Describe the types of documents
supported by WPF?
There are two kinds of document supported by WPF
a)Flow format:Flow format document adjusts as per screen
size and resolution
b)Fixed Format:Fixed Format document does not adjust as per
screen size and resolution
What namespaces are needed to host
a WPF control in Windows form application?
The following namespaces needs to be referenced:
a)PresentationCore.dll
b)PresentationFramework.dll
c)UIAutomationProvider.dll
d)UIAutomationTypes.dll
e)WindowsBase.dll
What is dependency property?
A property that is
support by the WPF property system is known as a dependency property.
Example:
<StackPanel
Canvas.Top="50" Canvas.Left="50" DataContext="{Binding
Source={StaticResource XmlTeamsSource}}">
<Button Height=”30” width=”80”
Content="{Binding XPath=Team/@TeamName}" Background="Red" Style="{StaticResource
GreenButtonStyle}"/>
</StackPanel>
Here Height, width, Baground etc are regular property but DataContext,
Style, ‘Canves.Lef’t, ‘Canves .right ‘are the dependency on this example, that
is call dependency property. I thing, all WPF binding control are dependency
property.
What is routed event in wpf?
A routed event is a CLR event that is support by an instance
of the Routed Event class and is processed by the Windows Presentation
Foundation (WPF) event system.
For example: Event bubbling is good concept routed event.
<StackPanel
Background="LightGray" Orientation="Horizontal" Button.Click="CommonClickHandler">
<Button Name="YesButton" Width="Auto" >Yes</Button>
</StackPanel>
What does mean "x:"
prefix in xaml code?
It is an xml namespace that usually refers to the xaml
namespace.
Example:
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
What is XBAP Stands?
XBAP Stands for XAML Browser application.
What is a .baml file?
An XAML file is compiled in .net, become a file with a .baml
extension, which stand for binary XAML.
Types of window in wpf?
Normal window
Navigate window
Page Window
What is dispatcher Object?
It is the main of all WPF controls which Take care UI
Thread.
What are the method in
DependencyObject in WPF?
ClearValue
SetValue
GetValue
What types of control in wpf?
Content control
Layout control
Item control
Can you create Window service in
WPF?
No! , It use for UI, we create a cervices using c# or other
language.
What is XBAP?
XBAP is stand for XAML Browser Application which is a new
Windows technology used for creating Rich Internet Applications.
While windows applications are normally compiled to an .exe
file, browser applications are compiled to an extension .xbap and can be run
inside Internet Explorer.
Xbap applications are run within a security sandbox to
prevent untrusted applications from controlling local system resources.
(e.gdeleting local files)
What is the differenece between
System.Windows.dll and System.Windows.Browser.dll?
1)System.Windows.dll:-This Assembly includes many of the
classes for building Silverlight user interfaces,including basic
elements,Shapes and Brushes,classes that support animation and databinding,and
the version of the FileOpenDialog that works with isolated storage.
2)System.Windows.Browser.dll:-This Assembly contains classes
for interacting with HTML Elements.
Name the Classes that contains
arbitrary content in WPF?
1)ContentControl:- A single arbitrary object.
2)HeaderedContentControl:- A header and a single item, both
of which are arbitrary objects.
3)ItemsControl:- A collection of arbitrary objects.
4)HeaderedItemsControl:- A header and a collection of items,
all of which are arbitrary objects.
Name the Events that are
implemented by NavigationService?
1)Navigating:- Occurs when a new navigation is requested.
Can be used to cancel the navigation.
2)NavigationProgress:- Occurs periodically during a download
to provide navigation progress information.
3)Navigated:- Occurs when the page has been located and
downloaded.
4)NavigationStopped:- Occurs when the navigation is stopped
(by calling StopLoading), or when a new navigation is requested while a current
navigation is in progress.
5)NavigationFailed:- Occurs when an error is raised while
navigating to the requested content.
6)LoadCompleted:- Occurs when content that was navigated to
is loaded and parsed, and has begun rendering.
7)FragmentNavigation:- Occurs when navigation to a content
fragment begins, which happens:
a)Immediately, if the desired
fragment is in the current content.
b)After the source content has been
loaded, if the desired fragment is in different content.
What is the default Orientation of
Stack Panel?
The Default Orientation of Stack Panel is 'Vertical'.
What are the major subsystems of
the Windows Presentation Foundation?
1) Object
2) Threading.DispatcherObject
3) Windows.DependancyObject
4) Windows.Media.Visuals
5) Windows.UIElements
6) Windows.FrameworkElement
7) Windows.Controls.Control
In Which NameSpace you will find a
'Popup' and 'Thumb' control in WPF?
In 'system.windows.controls.primitives' namespace
Name Some Methods of MediaElement
in WPF?
MediaElement has the following methods :-
1)Play:-Plays media from the current position.
2)Stop:-Stops and resets media to be played from the
beginning.
3)Pause:-Pauses media at the current position.
4)Close:-Closes the media.
How to Set Window Title Bar Name at
RunTime in WPF?
this.Title="TitleName";
In Which of the Following Definitions element you will find
a 'Width' and 'Height' of a Grid(TAG)
1)<Grid.RowDefinitions >
2)<Grid.ColumnDefinitions>
In <Grid.RowDefinitions > you will find a 'Height'
eg: <Grid.RowDefinitions >
<RowDefinition Height="50" />
</Grid.RowDefinitions>
In <Grid.ColumnDefinitions> you will find a 'Width'
eg:<Grid.ColumnDefinitions>
<ColumnDefinition Width="90" />
</Grid.ColumnDefinitions>
What are the Features of WPF?
The Features of WPF are:-
1)Device Independent Pixel (DPI).
2)Built-In Support for Graphics and Animation.
3)Redefine Styles and Control Templates.
4)Resource based Approach for every control.
5)New Property System & Binding Capabilities.
Name the Layout Panels of WPF?
These are the five most layout panels of WPF:-
1)Grid Panel
2)Stack Panel
3)Dock Panel
4)Wrap Panel
5)Canvas Panel
What are the difference between
CustomControls and UserControls in WPF?
CustomControl
(Extending an existing control):-
1)Extends an existing control with additional features.
2)Consists of a code file and a default style in
Themes/Generic.xaml.
3)Can be styled/templated.
4)The best approach to build a control library.
UserControl
(Composition):
1)Composes multiple existing controls into a reusable
"group".
2)Consists of a XAML and a code behind file.
3)Cannot be styled/templated.
4)Derives from UserControl.
What are the Advantages of XAML?
1)XAML code is short and clear to read.
2)Separation of designer code and logic.
3)Graphical design tools like Expression Blend require XAML
as source.
4)The separation of XAML and UI logic allows it to clearly
separate the roles of designer and developer.
Which class of the WPF is the base
class of all the user-interactive elements?
Control class is the base class of all the user-interactive
elements in WPF.
What is Markup
Extensions?
The most common markup extensions used in WPF application
programming are Binding, used for data binding expressions, and the resource
references StaticResource and DynamicResource.
<StackPanel>
<Border Style="{StaticResource PageBackground}"></Border>
</StackPanel>
What
is type convertor?
In the section,
it was stated that the attribute value must be able to be set by a string. The
basic, native handling of how strings are converted into other object types or
primitive values is based on the String type itself, in addition to native
processing for certain types such as DateTime or Uri. But many WPF types or
members of those types extend the basic string attribute processing behavior,
in such a way that instances of more complex object types can be specified as
strings and attributes.
About The X: prefix?
The prefix x: was used to map the XAML namespace
http://schemas.microsoft.com/winfx/2006/xaml, which is the dedicated XAML
namespace that supports XAML language constructs. This x: prefix is used for
mapping this XAML namespace in the templates for projects.
x:Key: Sets a
unique key for each resource in a ResourceDictionary.
Example:
<object
x:Key="stringKeyValue".../>
x:Class:
Specifies the CLR namespace and class name for the class that provides
code-behind for a XAML page.
Example:
<object x:Class="namespace.classname".../>
x:Name: Specifies
a run-time object name for the instance that exists in run-time code after an
object element is processed.
Example:
<object x:Name="XAMLNameValue".../>
x:Static: Enables
a reference that returns a static value that is not otherwise a XAML-compatible
property.
Example:
<object property="{x:Static
prefix:typeName.staticMemberName}" .../>
x:Type:
Constructs a Type reference based on a type name.
Example:
<object property="{x:Type prefix:typeNameValue}"
.../>
This example shows you how to create a simple Binding.
In this example, you have a Person object with a string
property named PersonName. The Person object is defined in the namespace called
SDKSample.
The following example instantiates the Person object with a
PersonName property value of Anil. This is done in the Resources section and
assigned an x:Key.
XAML
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:ak="clr-namespace:SDKSample"
Title="Simple
Data Binding Sample">
<Window.Resources>
<ak:Person
x:Key="myDataSource" PersonName="Anil"/>
</Window.Resources>
<Grid>
<TextBlock
Text="{Binding Path=PersonName, Source={StaticResource
myDataSource}}"/>
</Grid>
</Window>
As a result, the TextBlock appears with the value
"Anil".
MultiBinding:
</TextBlock >
