Unity C# 之使用 HttpWebRequest 基础知识/HttpWebRequest 进行异步Post 网络访问/数据流形式获取数据(Task/async/await)的代码简单实现

一、简单介绍

二、实现原理

三、注意事项

四、效果预览

五、关键代码

附录： HttpWebRequest 的一些基础知识

1、HttpWebRequest 常用属性

2、HttpWebRequest 中的 ContentType

3、HttpWebRequest 一般使用示例

4、HttpWebRequest json 文本 Post 请求示例

5、 HttpWebRequest multipart/form-data 文件上传示例

一、简单介绍

Unity 在开发中，网络访问：

可以使用 UnityWebRequest 访问，不过好似只能用协程的方式，并且访问只能在主线程中；
所以这里使用 C# 中的 HttpWebRequest，进行网络访问，而且 HttpWebRequest，允许在子线程中访问，在一些情况下可以大大减少主线程的网络访问压力；

这里使用 HttpWebRequest ，进行 Post 访问，并且Task 结合 async （await）的进行异步访问，最后使用 Stream 流式的形式获取数据，在这里做一个简单的记录，以便后期使用的时候参考。

二、实现原理

1、HttpWebRequest 创建 post 的请求

2、GetRequestStreamAsync 发起异步请求

3、GetResponseAsync 和 GetResponseStream 异步获取响应数据流

4、因为使用到异步，所以 async Task 返回异步获取的流数据

三、注意事项

1、获取更新的流数据打印是，注意每次更新下 buffer ，不然输出打印的结果可能不是预期的

// 循环获取流式数据while ((bytesRead = await reader.ReadAsync(buffer, 0, buffer.Length)) > 0){ sb.Append(buffer, 0, bytesRead); Console.WriteLine(buffer); buffer = new char[1024]; }

四、效果预览

五、关键代码

using System;using System.Net;using System.Text;namespace TestHttpWebRequestPostStream{internal class Program{static string m_Authorization = "Your_Authorization";static int TIMEOUT_TIME = 10000; // 超时时间static async Task Main(string[] args){string url = "Your_STREAM_URL";string postData = "Your_POST_DATA";string content = await PostRequestStreamToStringAsync(url, postData);Console.WriteLine("Response content:");Console.WriteLine(content);}static async Task PostRequestStreamToStringAsync(string url, string postData){try{HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;request.ReadWriteTimeout = TIMEOUT_TIME;request.Timeout = TIMEOUT_TIME;request.Method = "POST";request.ContentType = "application/json"; // 根据需要设定request.Headers.Add("user-token", "xxxxxxxx");// 根据需要设定request.Headers.Add("xxxx-authorization", m_Authorization); // 根据需要设定//流式发起请求using (Stream requestStream = await request.GetRequestStreamAsync()){byte[] dataBytes = Encoding.UTF8.GetBytes(postData);await requestStream.WriteAsync(dataBytes, 0, dataBytes.Length);}// 流式获取数据响应using (HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync())using (Stream responseStream = response.GetResponseStream())using (StreamReader reader = new StreamReader(responseStream)){StringBuilder sb = new StringBuilder();char[] buffer = new char[1024];int bytesRead;// 循环获取流式数据while ((bytesRead = await reader.ReadAsync(buffer, 0, buffer.Length)) > 0){sb.Append(buffer, 0, bytesRead);Console.WriteLine(buffer);buffer = new char[1024];}return sb.ToString();}}catch (Exception e){return e.Message;}}}}

附录： HttpWebRequest 的一些基础知识

1、HttpWebRequest 常用属性

AllowAutoRedirect：获取或设置一个值，该值指示请求是否应跟随重定向响应。
CookieContainer：获取或设置与此请求关联的cookie。
Credentials：获取或设置请求的身份验证信息。
KeepAlive：获取或设置一个值，该值指示是否与 Internet 资源建立持久性连接。
MaximumAutomaticRedirections：获取或设置请求将跟随的重定向的最大数目。
Proxy：获取或设置请求的代理信息。
SendChunked：获取或设置一个值，该值指示是否将数据分段发送到 Internet 资源。
Timeout：获取或设置请求的超时值。
UserAgent：获取或设置 User-agent HTTP 标头的值
ContentType：Http内容类型
Headers：指定组成 HTTP 标头的名称/值对的集合。

2、HttpWebRequest 中的 ContentType

普通文本: “text/plain”
JSON字符串: “application/json”
数据流类型(文件流): “application/octet-stream”
表单数据(键值对): “application/x-www-form-urlencoded”
多分部数据: “multipart/form-data”

3、HttpWebRequest 一般使用示例

//创建HttpWeb请求HttpWebRequest request = (HttpWebRequest)WebRequest.Create (url);//创建HttpWeb相应HttpWebResponse response = (HttpWebResponse)request.GetResponse ();Console.WriteLine ("Content length is {0}", response.ContentLength);Console.WriteLine ("Content type is {0}", response.ContentType);//获取response的流Stream receiveStream = response.GetResponseStream ();//使用streamReader读取流数据StreamReader readStream = new StreamReader (receiveStream, Encoding.UTF8);Console.WriteLine ("Response stream received.");Console.WriteLine (readStream.ReadToEnd ());response.Close ();readStream.Close ();

4、HttpWebRequest json 文本 Post 请求示例

使用application/json作为请求头，用来告诉服务端消息主体是序列化的JSON字符串。

/**url:POST请求地址*postData:json格式的请求报文,例如：{"key1":"value1","key2":"value2"}*/public static string PostUrl(string url, string postData){HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);req.Method = "POST";req.TimeOut = "800";//设置请求超时时间，单位为毫秒req.ContentType = "application/json";byte[] data = Encoding.UTF8.GetBytes(postData);req.ContentLength = data.Length;using (Stream reqStream = req.GetRequestStream()){reqStream.Write(data, 0, data.Length);reqStream.Close();}HttpWebResponse resp = (HttpWebResponse)req.GetResponse();Stream stream = resp.GetResponseStream();//获取响应内容string result = "";using (StreamReader reader = new StreamReader(stream, Encoding.UTF8)){result = reader.ReadToEnd();}return result;}

5、 HttpWebRequest multipart/form-data 文件上传示例

使用multipart/form-data作为请求头，用来告诉服务器消息主体是多发文件格式

multipart/form-data格式使用一长串字符作为boundtry封装线对字段进行分割。这也很符合multipart多个部分的语义，包含了多个部分集，每一部分都包含了一个content-desposition头，其值为form-data,以及一个name属性，其值为表单的字段名，文件输入框还可以使用filename参数指定文件名。content-type非必须属性，其值会根据文件类型进行变化，默认值是text/plain。multipart的每一个part上方是边界线，最后一个part的下方添加一个边界线。

/// /// 上传文件请求/// 
/// Url/// 文件路径/// 表单数据（字典格式）/// 上传回调public static void UploadRequest(string url, string filePath, Dictionary formDatas, Action callback){// 时间戳，用做boundarystring timeStamp = DateTime.Now.Ticks.ToString("x");//根据uri创建HttpWebRequest对象HttpWebRequest httpReq = (HttpWebRequest) WebRequest.Create(new Uri(url));httpReq.Method = "POST";httpReq.AllowWriteStreamBuffering = false; //对发送的数据不使用缓存httpReq.Timeout = 300000; //设置获得响应的超时时间（300秒）httpReq.ContentType = "multipart/form-data; boundary=" + timeStamp;//读取file文件FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);BinaryReader binaryReader = new BinaryReader(fileStream);//表单信息string boundary = "--" + timeStamp;string form = "";string formFormat = boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}\r\n";string formEnd = boundary + "\r\nContent-Disposition: form-data; name=\"{0}\"; filename=\"{1}\";\r\nContent-Type:application/octet-stream\r\n\r\n";foreach (var pair in formDatas){form += string.Format(formFormat, pair.Key, pair.Value);}form += string.Format(formEnd,"file", Path.GetFileName(filePath));byte[] postHeaderBytes = Encoding.UTF8.GetBytes(form);//结束边界byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + timeStamp + "--\r\n");long length = fileStream.Length + postHeaderBytes.Length + boundaryBytes.Length;httpReq.ContentLength = length; //请求内容长度try{//每次上传4kint bufferLength = 4096;byte[] buffer = new byte[bufferLength];//已上传的字节数long offset = 0;int size = binaryReader.Read(buffer, 0, bufferLength);Stream postStream = httpReq.GetRequestStream();//发送请求头部消息postStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);while (size > 0){postStream.Write(buffer, 0, size);offset += size;size = binaryReader.Read(buffer, 0, bufferLength);}//添加尾部边界postStream.Write(boundaryBytes, 0, boundaryBytes.Length);postStream.Close();//获取服务器端的响应using (HttpWebResponse response = (HttpWebResponse) httpReq.GetResponse()){Stream receiveStream = response.GetResponseStream();StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8);string returnValue = readStream.ReadToEnd();Debug.Log("upload result:"+returnValue);callback" />

`Unity 上的简单的异步封装使用`

`1、HttpWebRequest 异步 Post 获取数据`

using System;using System.IO;using System.Net;using System.Text;using System.Threading.Tasks;using UnityEngine;public class GptNormalWrapper : Singleton, IGptHttpWebRequestWrapper{const string GPT_URL = "Your_URL";const string AUTHORIZATION = "Your_AUTHORIZATION";const string USER_TOKEN = "123456";const int TIMEOUT_TIME = 10000; // 超时时间public string GptUrl => GPT_URL;public async Task PostRequestToStringAsync(string postData) {return await PostRequestToStringAsync(GptUrl, postData);}public async Task PostRequestToStringAsync(string url, string postData){try{HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;request.ReadWriteTimeout = TIMEOUT_TIME;request.Timeout = TIMEOUT_TIME;request.Method = "POST";request.ContentType = "application/json";request.Headers.Add("user-token", USER_TOKEN);request.Headers.Add("xxx-authorization", AUTHORIZATION);Debug.Log("[GptNormalWrapper] PostRequestToStringAsync msg = " + postData);byte[] jsonBytes = Encoding.UTF8.GetBytes(postData);request.ContentLength = jsonBytes.Length;Stream strStream = request.GetRequestStream();strStream.Write(jsonBytes, 0, jsonBytes.Length);strStream.Close();HttpWebResponse respone = (HttpWebResponse)await request.GetResponseAsync();Stream ns = respone.GetResponseStream();string responseContent = new StreamReader(ns, Encoding.UTF8).ReadToEnd();Debug.Log("[GptNormalWrapper] PostRequestToStringAsync 消息返回:" + responseContent);MessageBack textback = JsonUtility.FromJson(responseContent);Debug.Log($"[GptNormalWrapper] PostRequestToStringAsync answer content {textback.data.choices[0].message.content} ");return new(textback.data.choices[0].message.content);}catch (Exception e){Debug.LogError("[GptNormalWrapper] PostRequestToStringAsync error:" + e);}return new(GptChatCommonStringDefine.GPT_REQUEST_SERVER_FAILED);}}

`2、HttpWebRequest 异步 Post 流式的获取数据`

using System.Net;using System.Threading.Tasks;using System.Text;using System.IO;using UnityEngine;using System;public class GptStreamWrapper : Singleton, IGptHttpWebRequestWrapper{const string GPT_URL = "Your_URL";const string AUTHORIZATION = "Your_AUTHORIZATION";const string USER_TOKEN = "123456";const int TIMEOUT_TIME = 10000; // 超时时间public string GptUrl { get; } = GPT_URL;public async Task PostRequestToStringAsync(string postData) {return await PostRequestToStringAsync(GptUrl, postData);}public async Task PostRequestToStringAsync(string url, string postData){try{HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;request.ReadWriteTimeout = TIMEOUT_TIME;request.Timeout = TIMEOUT_TIME;request.Method = "POST";request.ContentType = "application/json";request.Headers.Add("user-token", USER_TOKEN);request.Headers.Add("xxx-authorization", AUTHORIZATION);//流式发起请求using (Stream requestStream = await request.GetRequestStreamAsync()){Debug.Log("[GptStreamWrapper] PostRequestStreamToStringAsync postData : " + postData);byte[] dataBytes = Encoding.UTF8.GetBytes(postData);await requestStream.WriteAsync(dataBytes, 0, dataBytes.Length);}// 流式获取数据响应using (HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync())using (Stream responseStream = response.GetResponseStream())using (StreamReader reader = new StreamReader(responseStream)){StringBuilder sb = new StringBuilder();char[] buffer = new char[1024];int bytesRead;// 循环获取流式数据while ((bytesRead = await reader.ReadAsync(buffer, 0, buffer.Length)) > 0){sb.Append(buffer, 0, bytesRead);Debug.Log("[GptStreamWrapper] PostRequestStreamToStringAsync getting steam data : " + buffer);buffer = new char[1024];}Debug.Log("[GptStreamWrapper] PostRequestStreamToStringAsync whole stream data : " + sb.ToString());return sb.ToString();}}catch (Exception e){Debug.Log("[GptStreamWrapper] PostRequestStreamToStringAsync Exception Message data : " + e.Message);return new(GptChatCommonStringDefine.GPT_REQUEST_SERVER_FAILED);}}}

Unity C# 之使用 HttpWebRequest 基础知识/HttpWebRequest 进行异步Post 网络访问/数据流形式获取数据(Task/async/await)的代码简单实现