为多条文本消息C#添加时间延迟

如果字符超过136，我们希望将消息拆分为多条（短信）文本消息。

但我们也希望确保第二条消息在第一条消息之后、第三条消息之前到达。

到目前为止，从我们所做的为数不多的测试来看，它似乎是这样工作的，但为了确保我们仍然希望增加大约3秒的延迟

Thread.Sleep是正确的方法吗？或者除了添加延迟之外还有其他解决方案吗？

这是代码：

    // Split message to send them as individual text messages
    string[] messages = splitMessage(request["message"], 132);
    for (int i = 0; i < messages.Length; i++)
    {
        HttpWebRequest _wr = (HttpWebRequest)WebRequest.Create(url);
        // Use the CredentialCache so you can attach the authentication to the request
        CredentialCache mycache = new CredentialCache { { new Uri(url), "Basic", new NetworkCredential(_username, _password) } };
        // use Basic Authentication
        _wr.Credentials = mycache;
        _wr.Method = "POST";
        _wr.ContentType = "application/json";
        _wr.Timeout = -1;   // not sure if necessary but it's not harmful
        // _data variable holds the data to be pushed to the server in the request.
        // this piece of data holds the request to send a text message from the application
        string _data = "{'"outboundSMSMessageRequest'":" +
                        "{'"address'": '"" + formatedAddress + "'",'"requestId'": '"" + request["requestId"] + "'"" +
                        ",'"outboundSMSTextMessage'": '"" + messages[i] + "'",'"senderAddress'": '"" + request["sender"] + "'"" +
                        _optional + "}}";
        //get a reference to the request-stream, and write the POST data (_data) to it
        using (var s = new StreamWriter(_wr.GetRequestStream()))
        {
                s.Write(_data);
        }
        //get response-stream, and use a streamReader to read the content
        try
        {
                HttpWebResponse _response = (HttpWebResponse)_wr.GetResponse();
        }
        catch (WebException ex)
        {
                using (StreamWriter file = new StreamWriter(@"D:'WEB'SMS'jsonResponse.txt", true))
                {
                        file.WriteLine("No good");
                }
                // Log exception and throw as for GET example above
                Trace.WriteLine("No good");
                Trace.WriteLine(ex);
        }
        using (Stream s = _wr.GetResponse().GetResponseStream())
        {
                using (StreamReader sr = new StreamReader(s))
                {
                        var jsonData = sr.ReadToEnd();
                        Trace.WriteLine("Server response: " + jsonData);
                        //decode jsonData with javascript serializer
                        using (StreamWriter file = new StreamWriter(@"D:'WEB'SMS'jsonResponse.txt", true))
                        {
                                file.WriteLine("Server response: " + jsonData);
                        }
                }
        }
}