xmlHTTPrequest状态码400

Question

我想从我的网络服务器获得回复。所以我发送一个GET命令到我的api路径＆＃34; auftraege＆＃34;，但是在xhht.send是一个错误＆＃34;状态代码400＆＃34;。服务器有一个控制器，用于监听＆＃34; auftraege＆＃34;并且只回应＆＃34;你好＆＃34;。

var xmlDoc = null;

function loadXML() {
var xhttp;
if (window.XMLHttpRequest) {
    xhttp = new XMLHttpRequest();
} else {
    xhttp = new ActiveXObject('Microsoft.XMLDOM');
}
xhttp.onreadystatechange = function () {
    if (this.readyState === 4 && this.status === 400) {
        updateXML(this);
    }
};
xhttp.open("GET", "auftraege", true);
xhttp.send('grant_type=client_credentials');
}

function updateXML(xml) {
xmlDoc = xml.responseText;
document.getElementById("auftraege").innerHTML = xmlDoc;
setTimeout(updateTime, 5000);
}
window.addEventListener("load", loadXML);

那是控制器：

[RestController(InstanceCreationType.Singleton)] 
public class AuftraegeController { 
  [UriFormat("/auftraege")] 
  public IGetResponse GetWithSimpleParameters() { 
    return new GetResponse( GetResponse.ResponseStatus.OK, "Hello");
  } 

这是网络服务器

    private HttpServer _httpServer;

    public async Task InitializeWebServer()
    {
        var restRouteHandler = new RestRouteHandler();
        restRouteHandler.RegisterController<AuftraegeController>();

        var configuration = new HttpServerConfiguration()
            .ListenOnPort(80)
            //.RegisterRoute("api", restRouteHandler)
            .RegisterRoute("/auftraege", restRouteHandler)
            .RegisterRoute(new StaticFileRouteHandler(@"Web"))
            .EnableCors();

        var httpServer = new HttpServer(configuration);
        _httpServer = httpServer;
        await httpServer.StartServerAsync();