无法将数据发布到MVC控制器

Question

我无法从Post向MVC controller提出angular 2 (typescript) service次请求。

export class LeaveService {
constructor(private _http: Http) { }

Add(model) {
    let headers = new Headers({
        'Content-Type':
        'application/json; charset=utf-8'
    });
    let options = new RequestOptions({ headers: headers });
    let body = JSON.stringify(model);
    return this._http.post('/api/SampleData', body,
        options).toPromise().catch(this.handleErrorPromise);
}

MVC控制器

[HttpPost]
public string Post([FromBody] Leave leave)
{
    Response.StatusCode = 200;

    try
    {

        // some logic

    }
    catch (Exception e)
    {
        Response.StatusCode = 400;
        return e.ToString();
    }
    return "OK";
}

我在我的控制器上设置了断点但实际上没有击中。 错误在哪里？