ASP.NET 3.5 中的 SendGrid Web API

Question

我正在使用 SendGrid 电子邮件服务通过 Web API (HttpWebRequest) 发送电子邮件。这是正在使用的代码，但我收到了 400 响应。

string url = "https://sendgrid.com/api/mail.send.xml";
string parameters = "api_user=" + api_user + "&api_key=" + api_key + "&to="                     + toAddress + "&toname=" + toName + "&subject=" + subject + "&text=" + text + "&from=" + fromAddress;

// Create Request
myHttpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);

myHttpWebRequest.Method = "POST";
// myHttpWebRequest.ContentType = "application/json; charset=utf-8";
myHttpWebRequest.ContentType = "text/xml";

CookieContainer cc = new CookieContainer();
myHttpWebRequest.CookieContainer = cc;

System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
byte[] postByteArray = encoding.GetBytes(parameters);
myHttpWebRequest.ContentLength = postByteArray.Length;
System.IO.Stream postStream = myHttpWebRequest.GetRequestStream();
postStream.Write(postByteArray, 0, postByteArray.Length);
postStream.Close();

// Get Response
string result="";
HttpWebResponse response = (HttpWebResponse)myHttpWebRequest.GetResponse();

Answer 1

您的主要问题是您向我们发送的内容类型为 text/xml，但我们只接受表单编码的内容或查询字符串。这是您尝试执行的操作的完整示例。

using System;
using System.IO;
using System.Net;

public class SendGridWebDemo
{
  static public void Main ()
  {
    string api_user = "your_sendgrid_username";
    string api_key = "your_sendgrid_key";
    string toAddress = "to@example.com";
    string toName = "To Name";
    string subject = "A message from SendGrid";
    string text = "Delivered by your friends at SendGrid.";
    string fromAddress = "from@example.com";

    string url = "https://sendgrid.com/api/mail.send.json";

    // Create a form encoded string for the request body
    string parameters = "api_user=" + api_user + "&api_key=" + api_key + "&to=" + toAddress + 
                        "&toname=" + toName + "&subject=" + subject + "&text=" + text + 
                        "&from=" + fromAddress;

    try
    {
      //Create Request
      HttpWebRequest myHttpWebRequest = (HttpWebRequest) HttpWebRequest.Create(url);
      myHttpWebRequest.Method = "POST";
      myHttpWebRequest.ContentType = "application/x-www-form-urlencoded";

      // Create a new write stream for the POST body
      StreamWriter streamWriter = new StreamWriter(myHttpWebRequest.GetRequestStream());

      // Write the parameters to the stream
      streamWriter.Write(parameters);
      streamWriter.Flush();
      streamWriter.Close();

      // Get the response
      HttpWebResponse httpResponse = (HttpWebResponse) myHttpWebRequest.GetResponse();

      // Create a new read stream for the response body and read it
      StreamReader streamReader = new StreamReader(httpResponse.GetResponseStream());
      string result = streamReader.ReadToEnd();

      // Write the results to the console
      Console.WriteLine(result);
    }
    catch(WebException ex)
    {
      // Catch any execptions and gather the response
      HttpWebResponse response = (HttpWebResponse) ex.Response;

      // Create a new read stream for the exception body and read it
      StreamReader streamReader = new StreamReader(response.GetResponseStream());
      string result = streamReader.ReadToEnd();

      // Write the results to the console
      Console.WriteLine(result);
    }
  }
}

Answer 2

@Swift 的回答是正确的。这是我使用 MVC Web 表单的答案。替换console.writeline等

<div class="form">
     <input class="input-text" type="text" id="RecipientName" name="RecipientName" value="Your Name *" onFocus="if(this.value==this.defaultValue)this.value='';" onBlur="if(this.value=='')this.value=this.defaultValue;">
     <input class="input-text" type="text" id="RecipientEmail" name="RecipientEmail" value="Your E-mail *" onFocus="if(this.value==this.defaultValue)this.value='';" onBlur="if(this.value=='')this.value=this.defaultValue;">
     <textarea class="input-text text-area" id="RecipientMessage" name="RecipientMessage" cols="0" rows="0" onFocus="if(this.value==this.defaultValue)this.value='';" onBlur="if(this.value=='')this.value=this.defaultValue;">Your Message *</textarea>
     <input class="input-btn" type="submit" id="EmailSendButton" name="EmailSendButton" value="send message" onclick="EmailData()">
     <div id="EmailConfirmation"></div>
</div>


<script>
    function EmailData() {
        $("#EmailSendButton").attr("disabled", "true");

        var url = "/Main/EmailData";
        var recipientName = $("#RecipientName").val();
        var recipientEmail = $("#RecipientEmail").val();
        var recipientMessage = $("#RecipientMessage").val();
        var postData = { 'Name': recipientName, 'Email': recipientEmail, 'Message': recipientMessage }
        $.post(url, postData, function (result) {
            $("#EmailConfirmation").css({ 'display': 'block' });
            $("#EmailConfirmation").text(result);
            $("#EmailConfirmation").fadeIn(2000)
        })
    }
</script>

视图模型

public class EmailDataViewModel
{
    public string Name { get; set; }
    [DataType(DataType.EmailAddress)]
    public string Email { get; set; }
    public string Message { get; set; }
}

控制器

public string EmailData(EmailDataViewModel viewModel)
    {
        string api_user = "username";
        string api_key = "password";
        string toAddress = "admin@webapp.com";
        string toName = "Administrator";
        string subject = "Message from your web app";
        string text = viewModel.Name + " " + viewModel.Message;
        string fromAddress = viewModel.Email;
        string url = "https://sendgrid.com/api/mail.send.json";
        // Create a form encoded string for the request body
        string parameters = "api_user=" + api_user + "&api_key=" + api_key + "&to=" + toAddress +
                            "&toname=" + toName + "&subject=" + subject + "&text=" + text +
                            "&from=" + fromAddress;

        try
        {
            //Create Request
            HttpWebRequest myHttpWebRequest = (HttpWebRequest)HttpWebRequest.Create(url);
            myHttpWebRequest.Method = "POST";
            myHttpWebRequest.ContentType = "application/x-www-form-urlencoded";

            // Create a new write stream for the POST body
            StreamWriter streamWriter = new StreamWriter(myHttpWebRequest.GetRequestStream());

            // Write the parameters to the stream
            streamWriter.Write(parameters);
            streamWriter.Flush();
            streamWriter.Close();

            // Get the response
            HttpWebResponse httpResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();

            // Create a new read stream for the response body and read it
            StreamReader streamReader = new StreamReader(httpResponse.GetResponseStream());
            string result = streamReader.ReadToEnd();

            // Write the results to the console
            Console.WriteLine(result);
        }
        catch (WebException ex)
        {
            // Catch any execptions and gather the response
            HttpWebResponse response = (HttpWebResponse)ex.Response;

            // Create a new read stream for the exception body and read it
            StreamReader streamReader = new StreamReader(response.GetResponseStream());
            string result = streamReader.ReadToEnd();

            // Write the results to the console
            Console.WriteLine(result);
        }

        return "Successful";
    }

Answer 3

使用位于 https://github.com/sendgrid/sendgrid-csharp 的 c# 代码库

//Create message
SendGrid myMessage = SendGrid.GetInstance();
myMessage.AddTo("anna@example.com");
myMessage.From = new MailAddress("john@example.com", "John Smith");
myMessage.Subject = "Testing the SendGrid Library";
myMessage.Text = "Hello World!";

// Add attachment
myMessage.AddAttachment(@"C:\file1.txt");

//Set up the transport
var credentials = new NetworkCredential("username", "password");
var transportWeb = Web.GetInstance(credentials);

// Send the email.
transportWeb.Deliver(myMessage);