C# 如何获取google oauth的访问令牌？

How to get access token for google oauth?

提问by Sagar

I am using C# (ASP.NET). I want to use Google OAuth for accessing the user profile detail in my app. I successfully got the authorization code but having a problem in getting the access token. I prefer the Google tutorials. In tutorial, I read that I have to send the request and get the response from google. For that, I use System.Net.HttpWebRequest/HttpWebResponse(am I going in the right way). I have used this code...

我正在使用 C# (ASP.NET)。我想使用 Google OAuth 访问我的应用程序中的用户个人资料详细信息。我成功获取了授权码，但在获取访问令牌时遇到了问题。我更喜欢谷歌教程。在教程中，我读到我必须发送请求并从谷歌获得响应。为此，我使用System.Net.HttpWebRequest/HttpWebResponse（我是否以正确的方式进行）。我用过这个代码...

byte[] buffer = Encoding.ASCII.GetBytes("?code=" + code + "&client_id=xxx&client_secret=xxx&redirect_uri=xxxx&grant_type=authorization_code");
HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://accounts.google.com");
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
req.ContentLength = buffer.Length;

Stream strm = req.GetRequestStream();
strm.Write(buffer, 0, buffer.Length);
strm.Close();

HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
Response.Write(((HttpWebResponse)resp).StatusDescription);

But, I got the error:

但是，我得到了错误：

The remote server returned an error: (405) Method Not Allowed.

远程服务器返回错误：(405) Method Not Allowed。

Update: Here variable codeis authorization code.

更新：这里的变量code是授权码。

采纳答案by Claudio Cherubino

I think you are sending the POST request to the wrong endpoint, the correct one is https://accounts.google.com/o/oauth2/token

我认为您将 POST 请求发送到错误的端点，正确的是 https://accounts.google.com/o/oauth2/token

回答by Neno

As I had similar problems in the process of implementing Google auth, I will post the code that works.. The last mentioned problem: error (400) Bad request could be caused by leading '?' in the above code..

由于我在实现谷歌身份验证的过程中遇到了类似的问题，我将发布有效的代码..最后提到的问题：错误（400）错误请求可能是由领先的'？'引起的。在上面的代码..

 string codeClient = "code="+ t +"&client_id=number.apps.googleusercontent.com&";
 string secretUri = "client_secret=yoursecret&" + "redirect_uri=path&"
      + "grant_type=authorization_code";
 postString = codeClient + secretUri;

 string url = "https://accounts.google.com/o/oauth2/token";

 HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url.ToString());
 request.Method = "POST";
 request.ContentType = "application/x-www-form-urlencoded";

 UTF8Encoding utfenc = new UTF8Encoding();
 byte[] bytes = utfenc.GetBytes(postString);
 Stream os = null;
 try
 {
      request.ContentLength = bytes.Length;
      os = request.GetRequestStream();
      os.Write(bytes, 0, bytes.Length);
 }
 catch
 { }

 try
 {
      HttpWebResponse webResponse = (HttpWebResponse) request.GetResponse();
      Stream responseStream = webResponse.GetResponseStream();
      StreamReader responseStreamReader = new StreamReader(responseStream);
      result = responseStreamReader.ReadToEnd();//parse token from result

回答by Sagar

My code is working, I have done mistakes in above two lines. It should be like this

我的代码正在运行，我在上面两行中犯了错误。应该是这样的

byte[] buffer = Encoding.ASCII.GetBytes("code=" + code + "&client_id=xxx&client_secret=xxx&redirect_uri=xxxx&grant_type=authorization_code");
HttpWebRequest req = (HttpWebRequest)WebRequest.Create("https://accounts.google.com/o/oauth2/token");

Remaining code is correct.

剩下的代码是正确的。

回答by Sunny Jim

The original request seems to be somewhat outdated. But I found that the Google's code examples contain lots of "Best Practices" housekeeping code that's hard to separate from the essential operations.

最初的请求似乎有些过时了。但我发现 Google 的代码示例包含大量“最佳实践”内务代码，这些代码很难从基本操作中分离出来。

I recently published a document that represents all the REST operations as curl commands. It's hard to be conversant in every language, but curl seems universal. Most people know it- otherwise, it's pretty easy to grasp. In my curl examples, the -dflag indicates a POST operation. Otherwise, the parameters are appended to the URL.

我最近发布了一个文档，将所有 REST 操作表示为 curl 命令。很难精通每种语言，但 curl 似乎很普遍。大多数人都知道——否则，它很容易掌握。在我的 curl 示例中，-d标志表示 POST 操作。否则，参数将附加到 URL。

http://www.tqis.com/eloquency/googlecalendar.htm

http://www.tqis.com/eloquency/googlecalendar.htm

回答by Sahil Bhatia

public string ReceiveTokenGmail(string code, string GoogleWebAppClientID, string GoogleWebAppClientSecret, string RedirectUrl)
{
    string postString = "code=" + code + "&client_id=" + GoogleWebAppClientID + @"&client_secret=" + GoogleWebAppClientSecret  + "&redirect_uri=" + RedirectUrl;

    string url = "https://accounts.google.com/o/oauth2/token";

    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url.ToString());
    request.Method = "POST";
    request.ContentType = "application/x-www-form-urlencoded";

    UTF8Encoding utfenc = new UTF8Encoding();
    byte[] bytes = utfenc.GetBytes(postString);
    Stream os = null;
    try
    {
        request.ContentLength = bytes.Length;
        os = request.GetRequestStream();
        os.Write(bytes, 0, bytes.Length);
    }
    catch
    { }
    string result = "";

    HttpWebResponse webResponse = (HttpWebResponse)request.GetResponse();
    Stream responseStream = webResponse.GetResponseStream();
    StreamReader responseStreamReader = new StreamReader(responseStream);
    result = responseStreamReader.ReadToEnd();

    return result;
}