C#通過HttpWebRequest發送帶有JSON Body的POST請求實現

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起因

很多博客都有描述到這個問題，那麼為什麼我還要寫一篇文章來說一下呢，因為其他的都似乎已經過時瞭，會導致其實body 並沒有發送過去。至於為什麼不使用其他的諸如 HttpClient 之類的，是由於業務需要。

原來的處理方式

通過 GetRequestStream 來獲取請求流，後把需要發送的 Json 數據寫入到流中

private T PostDataViaHttpWebRequest<T>(string baseUrl,
            IReadOnlyDictionary<string, string> headers,
            IReadOnlyDictionary<string, string> urlParas,
            string requestBody=null)
        {
            var resuleJson = string.Empty;
            try
            {
                var apiUrl = baseUrl;

                if (urlParas != null)
                    urlParas.ForEach(p =>
                    {
                        if (apiUrl.IndexOf("{" + p.Key + "}") > -1)
                        {
                            apiUrl = apiUrl.Replace("{" + p.Key + "}", p.Value);
                        }
                        else
                        {
                            apiUrl += string.Format("{0}{1}={2}", apiUrl.Contains("?") ? "&" : "?", p.Key, p.Value);
                        }
                    }
                );
                
                var req = (HttpWebRequest)WebRequest.Create(apiUrl);
                req.Method = "POST";
                req.ContentType = "application/json"; 
                req.ContentLength = 0;

                if (!requestBody.IsNullOrEmpty())
                {
                    using (var postStream = req.GetRequestStream())
                    {
                        var postData = Encoding.ASCII.GetBytes(requestBody);
                        req.ContentLength = postData.Length;
                        postStream.Write(postData, 0, postData.Length);
                    }
                }

                if (headers != null)
                {
                    if (headers.Keys.Any(p => p.ToLower() == "content-type"))
                        req.ContentType = headers.SingleOrDefault(p => p.Key.ToLower() == "content-type").Value;
                    if (headers.Keys.Any(p => p.ToLower() == "accept"))
                        req.Accept = headers.SingleOrDefault(p => p.Key.ToLower() == "accept").Value;
                }

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

                using(Stream stream = response.GetResponseStream())
                {
                    using (StreamReader reader = new StreamReader(stream, Encoding.GetEncoding("UTF-8")))
                    {
                        resuleJson = reader.ReadToEnd();
                    }
                }
            }
            catch (Exception ex)
            {
                return default(T);
            }
            return JsonConvert.DeserializeObject<T>(resuleJson);
        }

但是會發現，數據一直沒有正常發送過去，而且代碼還顯得比較復雜

新的方式

這裡修改一下寫入 RequestStream 的方式，使用 StreamWriter 包裝一下，然後直接寫入需要發送的 Json 數據

private T PostDataViaHttpWebRequest<T>(string baseUrl,
            IReadOnlyDictionary<string, string> headers,
            IReadOnlyDictionary<string, string> urlParas,
            string requestBody=null)
        {
            var resuleJson = string.Empty;
            try
            {
                var apiUrl = baseUrl;

                if (urlParas != null)
                    urlParas.ForEach(p =>
                    {
                        if (apiUrl.IndexOf("{" + p.Key + "}") > -1)
                        {
                            apiUrl = apiUrl.Replace("{" + p.Key + "}", p.Value);
                        }
                        else
                        {
                            apiUrl += string.Format("{0}{1}={2}", apiUrl.Contains("?") ? "&" : "?", p.Key, p.Value);
                        }
                    }
                );
                
                var req = (HttpWebRequest)WebRequest.Create(apiUrl);
                req.Method = "POST";
                req.ContentType = "application/json"; //Defalt

                if (!requestBody.IsNullOrEmpty())
                {
                    using (var postStream = new StreamWriter(req.GetRequestStream()))
                    {
                        postStream.Write(requestBody);
                    }
                }

                if (headers != null)
                {
                    if (headers.Keys.Any(p => p.ToLower() == "content-type"))
                        req.ContentType = headers.SingleOrDefault(p => p.Key.ToLower() == "content-type").Value;
                    if (headers.Keys.Any(p => p.ToLower() == "accept"))
                        req.Accept = headers.SingleOrDefault(p => p.Key.ToLower() == "accept").Value;
                }

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

                using(Stream stream = response.GetResponseStream())
                {
                    using (StreamReader reader = new StreamReader(stream, Encoding.GetEncoding("UTF-8")))
                    {
                        resuleJson = reader.ReadToEnd();
                    }
                }
            }
            catch (Exception ex)
            {
                return default(T);
            }
            return JsonConvert.DeserializeObject<T>(resuleJson);
        }

這樣即可正確發送 Json 數據。

到此這篇關於C#通過HttpWebRequest發送帶有JSON Body的POST請求實現的文章就介紹到這瞭,更多相關C# post請求 HttpWebRequest內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet！

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