Use the Source property to provide contact or group identity. With controls such as PresenceIndicator and ContactCard, the Source property identifies the contact to display. With controls such as StartAudioCallButton and StartVideoCallButton, the Source property identifies a contact to include in a conversation. The Source property is used by the following controls:

  • PresenceIndicator control

  • ContactCard control

  • StartInstantMessagingButton control

  • StartAudioCallButton control

  • SendEmailButton control

  • StartVideoCallButton control

  • ScheduleMeetingButton control

  • SendFileButton control

  • ShareDesktopButton control

Valid Types

The Source property has three valid types:

Expected Types of Strings

The Source property expects the following types of localizable strings:


  • SMTP address

  • E.164 phone number

Tip Tip

Observe the following guidelines when using the Source property:

  • If the value is a string that does not contain the sip:prefix, the control will perform a search, using the string specified as a search criteria, and will load the first contact in the result set matching the specified string. This behavior is not deterministic, and yields the slowest performance.

  • If the value is a SIP URI string qualified by the sip: prefix, the contact will be loaded using an exact match of the specified URI. This behavior is deterministic, and yields better performance.

  • If the value is a Contact or DistributionGroup object, it is used without any changes. This behavior is deterministic, and yields the best performance.