Sunday, 21 June 2015

Windows Phone Interview Questions Part1

1. Style:
A Style is basically a collection of property settings applied to multiple instances of the same type. AStyle contains a collection of one or more Setter objects. Each Setter has a Property and a Value. TheProperty is the name of the property of the element the style is applied to. The Value is the value that is applied to the property.
Implicit Styles: For example, if you create a style implicitly for all the ToggleButton controls in your application, and your application has ToggleButton and CheckBox controls (CheckBox derives from ToggleButton), the style is applied only to the ToggleButton controls.
BasedOn Styles: It is possible to build a new style based on an existing style. You can do this using the BasedOnproperty. This reduces the duplication of code and makes it easier to manage resources. Each style supports only one BasedOn style. 
2. UserControl:
Provides the base class for defining a new control that encapsulates related existing controls and provides its own logic.

3. LifeCycle Of WindowsPhone:
  App Launching=>Running=> OnNavigatedFrom(NavigationEventArgs)=>deactivated=>dormanent (stopped and no processing takes place)=>tombstoned(app has been terminated and it will be relaunched and the application can use the preserved data to restore state) =>Activated=> OnNavigatedTo(NavigationEventArgs) =>Closing=>raised when the user navigates backwards past the first page of an app
4. ContentTemplate:
Gets or sets the data template used to display the content of the ContentControl
ControlTemplate: Specifies the visual structure and behavioral aspects of a Control that can be shared across multiple instances of the control..
Control: Represents the base class for UI elements that use a ControlTemplate to define their appearance.
5. DataTemplate:
Describes the visual structure of a data object.
6. ItemTemplate:
·         Gets or sets the custom content for the data item in a control.ex:listbox
·         ItemsControl: Represents a control that can be used to present a collection of items.
·         ItemsPresenter: Specifies where items are placed in a control, usually an ItemsControl.
·          ItemPanelTemplate:specify the panel used to arrange the children of your ListBox.
·         ItemSource: Gets or sets a collection used to generate the content of the ItemsControl.
7. Layouts:
Windows Phone provides a flexible layout system that enables you to specify how controls are positioned on the screen.
i)Absolute layout(Canvas): you arrange child elements in a layout panel by specifying their exact locations relative to their parent element
ii)Dynamic Layout(Stack Panel,Grid): To use automatic or proportional sizing, you must assign special values to the Height andWidth properties.
8. StackPanel Vs Grid Vs Canvas Vs WrapPanel:
StackPanel: The StackPanel is a simple layout panel that arranges its child elements into a single line that can be oriented horizontally or vertically. 
Grid: The Grid control is the most flexible layout panel, and supports arranging controls in multi-row and multi-column layouts.
Canvas:  Canvas is useful for scenarios where the UI elements contained within it never move.
WrapPanel or WrapGrid : Positions child elements sequentially from left to right or top to bottom. When elements extend beyond the container edge, elements are positioned in the next row or column. In Windows Phone 8, consider using the WrapPanel available in the Windows Phone Toolkit.
9. What is  Diff B/W Grid column_2  2* and column_4  2*:
Suppose there  4 columns in grid
Column _2  2*: After the Auto columns are calculated, the column gets part of the remaining width. Column 2 will be one-half as wide as Column 4.
Column _4  2*: After the Auto columns are calculated, the column gets part of the remaining width. Column 4 will be two times as wide as Column 2.
10. Panel:
Provides a base class for all Panel elements. Use Panel elements to position and arrange child objects in Windows Phone applications.

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