在Fiddler中检查时，Angular2 POST调用将删除内容类型和正文

Question

这是我的客户端Angular2 Code。

public getOutletsAndBizInfos(agencyId: number, locationId: number): Promise<BizAssignInfoPack> {

    let payLoad: any = { AgencyId: agencyId, LocationId: locationId };
    let hdLClientPack: HdLClientPack = new HdLClientPack(payLoad, HdLCommands.GetBizAssignOutlets);
    let bodyContent = JSON.stringify(hdLClientPack);
    let headers = new Headers();
    headers.append('Content-Type','application/json' );
    let urlValue = Config.GetSrvBizAssignUrl();
    let reqOptions = new RequestOptions({ headers: headers , body: bodyContent, url: urlValue, method: RequestMethod.Post });
    return this.http.post(urlValue, bodyContent , reqOptions)
        .toPromise()
        .then(result => {
            // alert("Got data from server.");
            let payLoad = result.json().payLoad;
            let payLoadContent = JSON.parse(payLoad);
            return payLoadContent;
        })
        .catch(this.handleError);

}

当我在Fiddler中检查请求时，标题和正文都丢失了。这些是Fiddler的Raw内容。

===============

OPTIONS http://localhost:8012/api/srvbizassign/GetOutlets HTTP/1.1
Host: localhost:8012
Connection: keep-alive
Access-Control-Request-Method: POST
Origin: http://localhost:4200
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36
Access-Control-Request-Headers: content-type
Accept: */*

Accept-Encoding: gzip, deflate, sdch, br
Accept-Language: en-US,en;q=0.8    

HTTP/1.1 415 Unsupported Media Type

===============

不确定我错过了什么。有什么建议吗？