[null,null,["最后更新时间 (UTC)：2025-07-25。"],[[["\u003cp\u003e\u003ccode\u003ecast.framework.CastContext\u003c/code\u003e is a singleton object that manages cast interactions and states, including the cast icon and session object.\u003c/p\u003e\n"],["\u003cp\u003eIt provides methods for managing sessions, such as starting and ending them, retrieving the current session state, and adding or removing event listeners.\u003c/p\u003e\n"],["\u003cp\u003eCast interaction requires setting cast options using \u003ccode\u003esetOptions\u003c/code\u003e, and credentials can be optionally set using \u003ccode\u003esetLaunchCredentialsData\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eYou can retrieve the \u003ccode\u003eCastContext\u003c/code\u003e instance using \u003ccode\u003egetInstance\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003erequestSession\u003c/code\u003e method initiates the cast selection UI, enabling users to select a device and start a casting session.\u003c/p\u003e\n"]]],["The `CastContext` class manages cast interactions via a singleton instance. Key actions include: fetching the instance via `getInstance`, setting options with `setOptions`, and setting user credentials using `setLaunchCredentialsData`. It provides session management, allowing users to start sessions with `requestSession` and end them with `endCurrentSession`. It allows to manage event listeners via `addEventListener` and `removeEventListener` methods. `getCastState`, `getCurrentSession`, and `getSessionState` provide the current cast icon, session, and session states.\n"],null,["# Class: CastContext\n\ncast.[framework](/cast/docs/reference/web_sender/cast.framework).CastContext\n============================================================================\n\nclass static\n\nManages cast interaction. A singleton object that is fetched using\ngetInstance.\nManages states - provide the state of the cast icon, and session object.\nCast interaction is not supported till the cast options are provided by\nsetOptions.\n\nConstructor\n-----------\n\n### CastContext\n\nnew\nCastContext()\n\nMethods\n-------\n\n### getInstance\n\nstatic\n\ngetInstance() returns [cast.framework.CastContext](/cast/docs/reference/web_sender/cast.framework.CastContext)\n\nReturns the CastContext singleton instance.\n\nReturns\n\n: [cast.framework.CastContext](/cast/docs/reference/web_sender/cast.framework.CastContext) A singleton instance\n of the CastContext.\n\n### addEventListener\n\naddEventListener(type, handler)\n\nAdds an event listener.\n\n| #### Parameter ||\n|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| type | [cast.framework.CastContextEventType](/cast/docs/reference/web_sender/cast.framework#.CastContextEventType) Event type. Value must not be null. |\n| handler | (non-null function(non-null [cast.framework.CastStateEventData](/cast/docs/reference/web_sender/cast.framework.CastStateEventData)) or non-null function(non-null [cast.framework.SessionStateEventData](/cast/docs/reference/web_sender/cast.framework.SessionStateEventData))) |\n\n### endCurrentSession\n\nendCurrentSession(stopCasting)\n\nEnds current session.\n\n| #### Parameter ||\n|-------------|--------------------------------------------------------------------------|\n| stopCasting | boolean Should the receiver application be stopped or just disconnected. |\n\n### getCastState\n\ngetCastState() returns [cast.framework.CastState](/cast/docs/reference/web_sender/cast.framework#.CastState)\n\nReturns\n\n: `non-null `[cast.framework.CastState](/cast/docs/reference/web_sender/cast.framework#.CastState) Current cast icon state.\n\n### getCurrentSession\n\ngetCurrentSession() returns [cast.framework.CastSession](/cast/docs/reference/web_sender/cast.framework.CastSession)\n\nReturns\n\n: `nullable `[cast.framework.CastSession](/cast/docs/reference/web_sender/cast.framework.CastSession) Current session.\n\n### getSessionState\n\ngetSessionState() returns [cast.framework.SessionState](/cast/docs/reference/web_sender/cast.framework#.SessionState)\n\nReturns\n\n: `non-null `[cast.framework.SessionState](/cast/docs/reference/web_sender/cast.framework#.SessionState) Current session state.\n\n### removeEventListener\n\nremoveEventListener(type, handler)\n\nRemoves an event listener.\n\n| #### Parameter ||\n|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| type | [cast.framework.CastContextEventType](/cast/docs/reference/web_sender/cast.framework#.CastContextEventType) Event type. Value must not be null. |\n| handler | (non-null function(non-null [cast.framework.CastStateEventData](/cast/docs/reference/web_sender/cast.framework.CastStateEventData)) or non-null function(non-null [cast.framework.SessionStateEventData](/cast/docs/reference/web_sender/cast.framework.SessionStateEventData))) |\n\n### requestSession\n\nrequestSession() returns Promise containing nullable [chrome.cast.ErrorCode](/cast/docs/reference/web_sender/chrome.cast#.ErrorCode)\n\nOpens the cast selection UI, to allow user to start or stop session.\n\nThrows\n\n: `Error` If the context options were not provided yet.\n\nReturns\n\n: `non-null Promise containing nullable `[chrome.cast.ErrorCode](/cast/docs/reference/web_sender/chrome.cast#.ErrorCode) A promise to indicate session\n is starting, or failed (rejected with error code).\n\n### setLaunchCredentialsData\n\nsetLaunchCredentialsData(credentialsData)\n\nSets the user credentials data. Will be ignored if called before\nsetOptions. Calling setOptions after setLaunchCredentialsData will\nclear the value set in setLaunchCredentialsData.\n\n| #### Parameter ||\n|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| credentialsData | [chrome.cast.CredentialsData](/cast/docs/reference/web_sender/chrome.cast.CredentialsData) Credentials data used to identify the credentials of the sender. Value must not be null. |\n\n### setOptions\n\nsetOptions(options)\n\nSets the cast options.\nEvents will only be sent once config was provided.\n\n| #### Parameter ||\n|---------|---------------------------------------------------------------------------------------------------------------------------------------------|\n| options | [cast.framework.CastOptions](/cast/docs/reference/web_sender/cast.framework.CastOptions) Cast options for the page. Value must not be null. |\n\nThrows\n\n: `non-null Error` If the options are missing application id."]]
