Lunchers and Choosers

Here is the official document about lunchers and choosers overview for Windows Phone.

The difference between lanchers and choosers are: Launchers do not return data or status to your application; Choosers can return data and status to your application. However, if the user presses Start while the new application is open, the calling application may never be reactivated.

Microsoft.Phone.Tasks namespace allows applications to use Launchers and Choosers to provide a set of common tasks to their users, such as placing phone calls, sending email, and taking pictures. We need a reference to Microsoft.Phone.Tasks.

using Microsoft.Phone.Tasks;

This is pre-release documentation for the Windows Phone OS 7.1 development platform.

Classes

Class	Description
AddressChooserTask	Allows an application to launch the Contacts application. Use this to obtain the physical address of a contact selected by the user. How to: User the Address Chooser Task for Windows Phone.
AddressResult	Represents a physical address returned from a call to the Show() method. An example in How to: User the Address Chooser Task for Windows Phone.
BingMapsDirectionsTask	Allows an application to launch the Bing Maps application, specifying a starting location or an ending location, or both, for which driving directions are displayed. How to: Use the Bing Maps Directions Task for Windows Phone
BingMapsTask	Allows an application to launch the Bing Maps application centered at the location specified with the Center property or at the user’s current location. If SearchTerm is set, locations matching the search term are tagged on the map. How to: Use the Bing Maps Task for Windows Phone
CameraCaptureTask	Allows an application to launch the Camera application. Use this to allow users to take a photo from your application. How to: Use the Camera Capture Task for Windows Phone
ChooserBase<TTaskEventArgs>	The base class from which all Choosers are derived. This class exposes a common function for showing the Choosers and an event for handling the Chooser result.
ConnectionSettingsTask	Allows an application to launch a Settings dialog that allows the user to change the device’s network connection settings. How to: Use the Connection Settings Task for Windows Phone
EmailAddressChooserTask	Allows an application to launch the Contacts application. Use this to obtain the email address of a contact selected by the user. How to: Use the Email Address Chooser Task for Windows Phone
EmailComposeTask	Allows an application to launch the email application with a new message displayed. Use this to allow users to send email from your application. An example in How to Use the Email Compose Task for Windows Phone.
EmailResult	Represents an email address returned from a call to the Show method of a EmailAddressChooserTask object. An example in How to: User the Email Address Chooser Task for Windows Phone.
GameInviteTask	Allows an application to show a game invite screen that allows the user to invite players to a multiplayer game session. How to: Use the Game Invite Task for Windows Phone
LabeledMapLocation	Represents a geographic coordinate and an associated label that identifies it, such as the location of a business and the business name. This class is used with the BingMapsDirectionsTask class.
MarketplaceDetailTask	Allows an application to launch the Windows Phone Marketplace client application and display the details page for the specified product. How to: Use the Marketplace Detail Task for Windows Phone
MarketplaceHubTask	Allows an application to launch the Windows Phone Marketplace client application. How to: Use the Marketplace Hub Task for Windows Phone
MarketplaceReviewTask	Allows an application to launch the Windows Phone Marketplace client application and display the review page for the specified product. How to: Use the Marketplace Review Task for Windows Phone
MarketplaceSearchTask	Allows an application to launch the Windows Phone Marketplace client application and display the search results from the specified search terms. How to: Use the Marketplace Search Task for Windows Phone
MediaPlayerLauncher	Allows an application to launch the media player. How to: Use the Media Player Launcher for Windows Phone
PhoneCallTask	Allows an application to launch the Phone application. Use this to allow users to make a phone call from your application. How to: Use the Phone Call Task for Windows Phone
PhoneNumberChooserTask	Allows an application to launch the Contacts application. Use this to obtain the phone number of a contact selected by the user. How to: Use the Phone Number Chooser Task for Windows Phone
PhoneNumberResult	Represents a phone number returned from a call to the Show method of a PhoneNumberChooserTask object.
PhotoChooserTask	Allows an application to launch the Photo Chooser application. Use this to allow users to select a photo. How to: Use the Photo Chooser Task for Windows Phone
PhotoResult	Represents a photo returned from a call to the Show method of a PhotoChooserTask object or a CameraCaptureTask object.
SaveContactResult	Contains the result of an attempt to save a contact.
SaveContactTask	Provides methods and events for launching the contacts application and enabling a user to save a contact. An example in How to: Use the Save Contact Task for Windows Phone.
SaveEmailAddressTask	Allows an application to launch the contacts application. Use this to allow users to save an email address from your application to a new or existing contact. An example in How to: Use the Save Email Address Task for Windows Phone.
SavePhoneNumberTask	Allows an application to launch the contacts application. Use this to allow users to save a phone number from your application to a new or existing contact. How to: Use the Save Phone Number Task for Windows Phone
SaveRingtoneTask	Enables an application to launch the ringtones application. Use theSaveRingtoneTask to allow users to save a ringtone from your application to the system ringtones list. How to: Use the Save Ringtone Task for Windows Phone
SearchTask	Allows an application to launch the Web Search application. How to: Use the Search Task for Windows Phone
ShareLinkTask	Allows an application to launch a dialog that enables the user to share a link on the social networks of their choice. How to: Use the Share Link Task for Windows Phone
ShareStatusTask	Allows an application to launch a dialog that enables the user to share a status message on the social networks of their choice. How to: Use the Share Status Task for Windows Phone
ShareTaskBase	The base class for the social network sharing APIs, ShareLinkTask andShareStatusTask.
SmsComposeTask	Launches the Messaging application with a new SMS message displayed. An example in How to: Use the SMS Compose Task for Windows Phone.
TaskEventArgs	The EventArgs used by the Completed event for all Choosers.
WebBrowserTask	Allows an application to launch the web browser application. How to: Use the Web Browser Task for Windows Phone

Enumerations

Enumeration	Description
ConnectionSettingsType	Lists the network connection settings types supported by ConnectionSettingsTask. · WiFi WiFi Settings · Bluetooth Bluetooth Settings · Cellular Cellular Settings · AirplaneMode Airplane Mode Settings
MarketplaceContentType	Defines the list of content types that can be shown by the Windows Phone Marketplace client application. This enumeration is used by MarketplaceDetailTask,MarketplaceHubTask, and MarketplaceSearchTask. · Applications Application content. · Music Music content.
MediaLocationType	Lists the data stores in which a media file can be stored. Used byMediaPlayerLauncher. · None The media item is in neither data store. The Show method will throw a FileNotFoundException if this value is used. · Install The media file is in the application’s installation directory. · Data The media file is in isolated storage.
MediaPlaybackControls	An enumeration defining the bitwise flags that are used with the Controls property of the MediaPlayerLauncher object to specify which controls should be displayed by the media player application. · None No controls. · Pause The pause control. · Stop The stop control. · FastForward The fast forward control. · Rewind The rewind control. · Skip The skip control. · All All controls. The equivalent of using OR to combine all of the other members of the enumeration.
MediaPlayerOrientation	Defines the list of orientations in which the media player can be launched. · Landscape Landscape orientation. · Portrait Portrait orientation.
TaskResult	Describes the success status of a chooser operation. · None No success status was returned from the chooser operation. · OK The chooser operation was successful. · Cancel The chooser operation was cancelled by the user.