不涉及任何数字或空值解析的 C# FormatException

Question

此行抛出 FormatException:

var dataString = string.Format("email_address:{0}, status:subscribed, merge_fields:{1}", "a", "b");

毫无疑问，问题很明显，但我没有看到。

函数如下:

   public static string AddSubscriber(string listId, Subscriber subscriber) {

            string url = string.Format("https://us10.api.mailchimp.com/3.0/lists/{0}/members/", listId);

            var req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "POST";
            req.ContentType = "application/json";
            req.Headers.Add("AUTHORIZATION", basicAuth);

            var mergeFieldJson = subscriber.MergeFields();
            var dataString = string.Format("email_address:{0}, status:subscribed, merge_fields:{1}", "a", "b"); // subscriber.email, mergeFieldJson);

            /*
            byte[] data = System.Text.Encoding.UTF8.GetBytes(dataString);
            using (var stream = req.GetRequestStream()) {
                stream.Write(data, 0, data.Length);
            }

            HttpWebResponse response = (HttpWebResponse)req.GetResponse();

            return new StreamReader(response.GetResponseStream()).ReadToEnd();
            */
            return "";
        }

异常(exception)情况:

Input string was not in a correct format. 
    at System.Text.StringBuilder.AppendFormat(IFormatProvider provider, String format, Object[] args)
    at System.String.Format(IFormatProvider provider, String format, Object[] args)
    at MailChimpLib.MailChimp.AddSubscriber(String listId, Subscriber subscriber) in d:\Development\GTPRepository\team24x7\trunk\MailChimpLib\MailChimp.cs:line 40
    at team24x7.Controllers.StoreController.AddTestSubscriber() in d:\Development\GTPRepository\team24x7\trunk\team24x7\api_source\Controllers\StoreController.cs:line 167

第 40 行是带有 string.Format(..) 的行。

这是 MergeFields 函数:

   public string MergeFields() {
        return string.Format("{'Email':'{0}','First Name':'{1}','Last Name':'{2}','Mascot':'{3}','Store Link':'{4}','School':'{5}'}",
            email, firstname, lastname, mascot, storelink, school
        );
    }

对我来说，它在 Debug模式下工作，但在 Release模式下调用它之后的行中会导致异常。

毫无疑问，这个问题与在格式字符串中包含初始和结束花括号的愚蠢和错误的尝试有关。 (愚蠢的诅咒。)

Answer 1

我在 Ideone 中运行了您的代码，它运行良好。

https://ideone.com/cHQC3O

using System;

public class Test
{
    public static void Main()
    {
        var dataString = string.Format("email_address:{0}, status:subscribed, merge_fields:{1}", "a", "b");
        Console.WriteLine(dataString);
    }
}

似乎我们遗漏了代码中未提及的内容。

你遇到了什么异常？异常信息是什么？