create static method
引擎构建方法
appKey
开发者后台获取的 AppKeyoptions
引擎相关配置项
Implementation
static Future<RCIMIWEngine> create(
String appKey,
RCIMIWEngineOptions options,
) async {
_instance ??= RCIMIWEngine();
return _instance!._create(appKey, options);
}