Asp.net mvc 谷歌安全浏览V4-无法发送请求

我一直在研究谷歌安全浏览API——我确信我做的一切都是正确的，但当我尝试连接到API时，我会出错

“对象引用未设置为对象的实例。”

我安装了正确的nuGet软件包

我的代码如下

try
{
    //cient_info
    Google.Apis.Safebrowsing.v4.Data.ClientInfo client = new Google.Apis.Safebrowsing.v4.Data.ClientInfo();
    client.ClientId = "testapp";
    client.ClientVersion = "1";

    //thread_info
    Google.Apis.Safebrowsing.v4.Data.ThreatInfo threadInfo = new Google.Apis.Safebrowsing.v4.Data.ThreatInfo();
    threadInfo.ThreatTypes.Add("MALWARE");
    threadInfo.ThreatTypes.Add("SOCIAL_ENGINEERING");
    threadInfo.PlatformTypes.Add("WINDOWS");
    threadInfo.ThreatEntryTypes.Add("URL");

    //url to check
    Google.Apis.Safebrowsing.v4.Data.ThreatEntry ITEM = new Google.Apis.Safebrowsing.v4.Data.ThreatEntry();
    ITEM.Url = "http://www.google.com.au/";
    threadInfo.ThreatEntries.Add(ITEM);

    //API Call
    var googleClient = new WebClient();
    var response = googleClient.DownloadString("https://safebrowsing.googleapis.com/v4/" + client + threadInfo + "&key=myapikey");
    var releases = JObject.Parse(response);
    return releases.ToString();
}
catch (Exception X)
{
    var Error = X.Message;
    return Error.ToString();
}

我想我把

var response=googleClient.DownloadString

搞砸了，但我不确定什么是正确的调用方法

有人知道吗

---

干杯

您需要输入api密钥

googleClient.DownloadString("https://safebrowsing.googleapis.com/v4/" + client + threadInfo + "&key=myapikey");

---

我使用了

ThreatMatches.Find（）

，它成功了

ThreatMatchesResource.FindRequest request = service.ThreatMatches.Find(
new FindThreatMatchesRequest{Client = client, ThreatInfo = threatInfo});

FindThreatMatchesResponse execute = await request.ExecuteAsync();

var releases = execute.ToString();

---

你确定你添加了API密钥吗？老实说，我不记得我是怎么修复的。。。干杯唯一重要的是它是固定的：D