很多博客都有描述到这个问题，那么为什么我还要写一篇文章来说一下呢，因为其他的都似乎已经过时了，会导致其实body 并没有发送过去。至于为什么不使用其他的诸如 HttpClient 之类的，是由于业务需要。
通过 GetRequestStream 来获取请求流，后把需要发送的 Json 数据写入到流中
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);
}
但是会发现，数据一直没有正常发送过去，而且代码还显得比较复杂
这里修改一下写入 RequestStream 的方式，使用 StreamWriter 包装一下，然后直接写入需要发送的 Json 数据
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);
}
这样即可正确发送 Json 数据。
