Angular 5.2自定义HttpClient类-无法将responseType更改为blob

我在我的项目中使用Angular 5.2版本，将默认响应类型更改为带有新函数的blob时遇到了问题

现在我想将responseType更改为blob以下载excel文件，但它对我不起作用

在我的项目中，我创建了包装器类CustomHttpClient来进行Get或Post调用

CustomHttpClient类如下所示：-

    export interface IRequestOptions {

    headers?: HttpHeaders;
    observe?: 'body';
    params?: HttpParams;
    reportProgress?: boolean;
    responseType?: 'json';
    withCredentials?: boolean;
    body?: any;
}


/*Custom HttpClient Class for making the WebAPI calls.*/
export class CustomHttpClient {

    _defaultHeaderType = new HttpHeaders({ 'Content-Type': 'application/json' });

    // Extending the HttpClient through the Angular DI.
    public constructor(public _http: HttpClient) {

    }

  public Get<T>(endPoint: string, options?: IRequestOptions): Observable<T> {
        if (options == undefined) {
            options = <IRequestOptions>{};
            options.headers = this._defaultHeaderType
        }

        options.headers = this.injectClient(options.headers);
        return this._http.get<T>(endPoint, options);
    }

    public GetBlob<T>(endPoint: string, options?: IRequestOptions): Observable<T> {
        if (options == undefined) {
            options = <IRequestOptions>{};
            options.headers = this._defaultHeaderType
        }

        //This line is giving error
         options.responseType = 'blob';

        options.headers = this.injectClient(options.headers);
        return this._http.get<T>(endPoint, options);
    }
}

downloadTemplate(): Observable<any> {
    let opt = {
        headers: new HttpHeaders({ 'Content-Type': 'application/json', 'Accept': 'application/xlsx'}),
        options: new RequestOptions({ responseType: ResponseContentType.Blob })
    }

    return this._httpObj.GetBlob(this._baseUrl + 'DownloadTemplate', opt);
}

现在我想调用GetBlob函数，并将responseType更改为'blob'。但它向我展示了错误类型blob不能分配给Json类型

在组件服务类中，我这样调用fn：-

    export interface IRequestOptions {

    headers?: HttpHeaders;
    observe?: 'body';
    params?: HttpParams;
    reportProgress?: boolean;
    responseType?: 'json';
    withCredentials?: boolean;
    body?: any;
}


/*Custom HttpClient Class for making the WebAPI calls.*/
export class CustomHttpClient {

    _defaultHeaderType = new HttpHeaders({ 'Content-Type': 'application/json' });

    // Extending the HttpClient through the Angular DI.
    public constructor(public _http: HttpClient) {

    }

  public Get<T>(endPoint: string, options?: IRequestOptions): Observable<T> {
        if (options == undefined) {
            options = <IRequestOptions>{};
            options.headers = this._defaultHeaderType
        }

        options.headers = this.injectClient(options.headers);
        return this._http.get<T>(endPoint, options);
    }

    public GetBlob<T>(endPoint: string, options?: IRequestOptions): Observable<T> {
        if (options == undefined) {
            options = <IRequestOptions>{};
            options.headers = this._defaultHeaderType
        }

        //This line is giving error
         options.responseType = 'blob';

        options.headers = this.injectClient(options.headers);
        return this._http.get<T>(endPoint, options);
    }
}

downloadTemplate(): Observable<any> {
    let opt = {
        headers: new HttpHeaders({ 'Content-Type': 'application/json', 'Accept': 'application/xlsx'}),
        options: new RequestOptions({ responseType: ResponseContentType.Blob })
    }

    return this._httpObj.GetBlob(this._baseUrl + 'DownloadTemplate', opt);
}

---

尝试更改iRequestStoptions接口，使响应类型为字符串类型。 像这样：

  export interface IRequestOptions {

    headers?: HttpHeaders;
    observe?: 'body';
    params?: HttpParams;
    reportProgress?: boolean;
    responseType?: string;
    withCredentials?: boolean;
    body?: any;
}

---

最近也有同样的问题，希望有时间能解决。 我使用Object.assign作为解决方法：

this._http.get<T>(endPoint, Object.assign(options, { responseType: 'blob' }))

这样你就可以在ts类型检查中作弊