## Response 使用指定值创建`Response`实例。 Though this object isn't usually instantiated by end-users, it is the primary object interacted with when it comes time to add data to a view. ```typescript http.request('my-friends.txt').subscribe(response => this.friends = response.text()); ``` The Response's interface is inspired by the Response constructor defined in the Fetch Spec, but is considered a static value whose body can be accessed many times. There are other differences in the implementation, but this is the most significant. ### 类定义 ```typescript class Response extends Body { constructor(responseOptions: ResponseOptions) type : ResponseType ok : boolean url : string status : number statusText : string bytesLoaded : number totalBytes : number headers : Headers toString() : string } ``` ### 属性 - type : `ResponseType` “basic", "cors", "default", "error" 或者 "opaque", 默认为 "default" - ok : `boolean` 如果响应状态在200-299内为`True` - url : `string` 响应URL, 默认为空字符串 - status : `number` 服务器返回的状态码，默认为200 - statusText : `string` Text representing the corresponding reason phrase to the status, as defined in [ietf rfc 2616 section 6.1.1](https://tools.ietf.org/html/rfc2616#section-6.1.1)，默认为"OK" - bytesLoaded : `number` Non-standard property Denotes how many of the response body's bytes have been loaded, for example if the response is the result of a progress event. totalBytes : `number` Non-standard property Denotes how many bytes are expected in the final response body. headers : `Headers` Headers object based on the Headers class in the [Fetch Spec](https://fetch.spec.whatwg.org/#headers-class). toString() : `string`