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

2024-03-07 前端 0

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<string> 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<string> 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。

/// <summary>/// 上传文件请求/// </summary>/// <param name="url">Url</param>/// <param name="filePath">文件路径</param>/// <param name="formDatas">表单数据（字典格式）</param>/// <param name="callback">上传回调</param>public static void UploadRequest(string url, string filePath, Dictionary<string,string> formDatas, Action<string> callback){    // 时间戳，用做boundary    string 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4k        int 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?.Invoke(returnValue);                        response.Close();            readStream.Close();        }    }    catch (Exception ex)    {        Debug.Log("文件传输异常： " + ex.Message);    }    finally    {        fileStream.Close();        binaryReader.Close();    }}

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<GptNormalWrapper>, 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<string> PostRequestToStringAsync(string postData) {        return await PostRequestToStringAsync(GptUrl, postData);    }    public async Task<string> 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<MessageBack>(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<GptStreamWrapper>, 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<string> PostRequestToStringAsync(string postData) {        return await PostRequestToStringAsync(GptUrl, postData);    }    public async Task<string> 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);        }    }}

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