Making http post request to webservice

I'm doing a http request here for a webservice apsh , to make a request I do this:

validaLogin(user: User) {
    var data = JSON.stringify({ email: user.email, senha: user.senha });

    console.log(data);

    return this.http.post(this.url, data)
        .do(this.logResponde)
        .map(this.extractData)
        .catch(this.catchError);
}

private catchError(error: Response | any) {
    console.log(error);
    return Observable.throw(error.json().error || "Erro de conexção");
}

private logResponde(res: Response) {
    console.log(res);
}

private extractData(res: Response) {
    return res.json();
}

and in webservice I get like this:

string email = context.Request.Form["email"];
string senha = context.Request.Form["senha"];

I can not change the ws just the way to make a request.

The problem that is occurring is that everything null is arriving.

Where am I going wrong?

  

I'm guessing it's a question of body or something like that.