C#开发WinForm之Http请求

秒速五厘米 2022-04-11 03:16 1550阅读 0赞

## C\#开发WinForm之Http请求 ##

### 文章目录 ###

*   *  C\#开发WinForm之Http请求
 *  前言
 *  http请求工具库里
 *  使用方法
 *   *  Get请求
     *  Post请求
 *  扩展
 *   *  文件上传
     *  文件下载

# 前言 #

HTTP请求是常见的web开发请求，简历也容易上手，当然对于 前端来说，jsweb的http很熟悉，而换种语言的c\#是怎样的呢？

Newtonsoft.Json是一个处理json格式的c\#库，我们可以去下载它并学习使用它。

# http请求工具库里 #

我的工具库里使用了HttpClient。

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Net;
    using System.Net.Security;
    
    
    using System.IO;
    using System.Net.Http;
    using System.Net.Http.Headers;
    using System.Xml.Serialization;
    using DongliCAD.utils;
    using Newtonsoft.Json;
    using Newtonsoft.Json.Linq;
    using System.Windows.Forms;
    using System.Text.RegularExpressions;
    using Bricscad.ApplicationServices;
    using Bricscad.EditorInput;
    using DongliCAD.common;
    
    namespace DongliCAD.utils
    {
        class HttpUtil
        {
           
            /// <summary>
            /// get请求
            /// </summary>
            /// <param name="url"></param>
            /// <returns></returns>
            public static JObject GetResponse(string url)
            {
                try
                {
                    if (string.IsNullOrEmpty(url))
                    {
                        throw new ArgumentNullException("url");
                    }
                    if (url.StartsWith("https"))
                        System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
    
                    HttpClient httpClient = new HttpClient();
                    httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                    if (GlobalData.Authorization.Length > 0)
                    {
                        httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                    }
                    HttpResponseMessage response = httpClient.GetAsync(url).Result;
                    StatusCodeHandler(response);
                    if (response.IsSuccessStatusCode)
                    {
                        string result = response.Content.ReadAsStringAsync().Result;
                        JObject jo = (JObject)JsonConvert.DeserializeObject(result);
                        return jo;
                    }
                }
                catch(Exception e)
                {
                    string msg = e.InnerException.InnerException.Message;
                    if(msg == "无法连接到远程服务器")
                    {
                        AlertUtil.Show("服务器无响应，请重新配置环境");
                        exceptionHandler("连接失败");
                    }
                }
                return new JObject();
            }
    
            public static T GetResponse<T>(string url)
                  where T : class, new()
            {
                T result = default(T);
                if (string.IsNullOrEmpty(url))
                {
                    throw new ArgumentNullException("url");
                }
                if (url.StartsWith("https"))
                    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
    
                HttpClient httpClient = new HttpClient();
                httpClient.DefaultRequestHeaders.Accept.Add(
                    new MediaTypeWithQualityHeaderValue("application/json"));
                if (GlobalData.Authorization.Length > 0)
                {
                    httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                }
                try { 
                    HttpResponseMessage response = httpClient.GetAsync(url).Result;
                    StatusCodeHandler(response);
                    
                    if (response.IsSuccessStatusCode)
                    {
                        Task<string> t = response.Content.ReadAsStringAsync();
                        string s = t.Result;
                        result = JsonConvert.DeserializeObject<T>(s);
                    }
                }
                catch(Exception e)
                {
                    string msg = e.InnerException.InnerException.Message;
                    if(msg == "无法连接到远程服务器")
                    {
                        AlertUtil.Show("服务器无响应，请重新配置环境");
                        exceptionHandler("连接失败");
                    }
                }
                return result;
            }
    
            /// <summary>
            /// post请求
            /// </summary>
            /// <param name="url"></param>
            /// <param name="postData">post数据</param>
            /// <returns></returns>
            public static JObject PostResponse(string url, string postData)
            {
                if (string.IsNullOrEmpty(url))
                {
                    throw new ArgumentNullException("url");
                }
                if (url.StartsWith("https"))
                    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
    
                HttpContent httpContent = new StringContent(postData);
                httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
                HttpClient httpClient = new HttpClient();
                if (GlobalData.Authorization.Length > 0)
                {
                    httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                }
                try {
                    HttpResponseMessage response = httpClient.PostAsync(url, httpContent).Result;
                    StatusCodeHandler(response);
                    AuthorizationHandler(response, url);
                    if (response.IsSuccessStatusCode)
                    {
                        string result = response.Content.ReadAsStringAsync().Result;
                        JObject jo = (JObject)JsonConvert.DeserializeObject(result);
                        return jo;
                    }
                }
                catch (Exception e)
                {
                    string msg = e.InnerException.InnerException.Message;
                    if (msg == "无法连接到远程服务器")
                    {
                        AlertUtil.Show("服务器无响应，请重新配置环境");
                        exceptionHandler("连接失败");
                    }
                }
                return new JObject();
            }
    
            private static Boolean StatusCodeHandler(HttpResponseMessage response)
            {
                Boolean ct = true;
                String statusCode = response.StatusCode.ToString();
                string result = response.Content.ReadAsStringAsync().Result;
                JObject jo = (JObject)JsonConvert.DeserializeObject(result);
                if (statusCode == HttpStatusCode.Unauthorized.ToString())
                {
                    AlertUtil.Show("请重新登陆");
                    LoginForm login = new LoginForm();
                    login.ShowDialog();
                } else if (statusCode == HttpStatusCode.Forbidden.ToString())
                {
                    AlertUtil.Show("禁止访问" + jo["data"]["msg"]);
                }
                else if (statusCode == HttpStatusCode.NotFound.ToString())
                {
                    AlertUtil.Show("请求失败");
                }else if(statusCode == HttpStatusCode.BadRequest.ToString())
                {
                    AlertUtil.Show("400");
                }
    
                return ct;
            }
    
            private static void AuthorizationHandler(HttpResponseMessage response, string url)
            {
                Regex reg = new Regex("(.+)/login$");
                Boolean isLogin = reg.IsMatch(url);
                if (isLogin)
                {
                    GlobalData.Authorization = getHeaderByKey(response, "Authorization");
                }
            }
    
            private static string getHeaderByKey(HttpResponseMessage response, string key)
            {
                string result = "";
                string header = response.Headers.ToString();
                string[] headers = header.Split("\r\n".ToCharArray());
                if(headers.Count() > 0)
                {
                    foreach (string item in headers)
                    {
                        Regex reg = new Regex("^"  + key + ":(.+)");
                        if (reg.IsMatch(item))
                        {
                            string[] tokens = item.Split(':');
                            if (tokens[0].ToString() == key)
                            {
                                result = tokens[1].ToString();
                                break;
                            }
                        }
                        else
                        {
                            reg = new Regex("^" + key + "=(.+)");
                            if (reg.IsMatch(item))
                            {
                                string[] tokens = item.Split('=');
                                if (tokens[0].ToString() == key)
                                {
                                    result = tokens[1].ToString();
                                    break;
                                }
                            }
                        }
                    }
    
                }
                return result;
            }
    
            /// <summary>
            /// 发起post请求
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="url">url</param>
            /// <param name="postData">post数据</param>
            /// <returns></returns>
            public static T PostResponse<T>(string url, string postData)
               where T : class, new()
            {
                if (string.IsNullOrEmpty(url))
                {
                    throw new ArgumentNullException("url");
                }
                if (url.StartsWith("https"))
                    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
    
                HttpContent httpContent = new StringContent(postData);
                httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
                HttpClient httpClient = new HttpClient();
    
                T result = default(T);
                if (GlobalData.Authorization.Length > 0)
                {
                    httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                }
                try
                {
                    HttpResponseMessage response = httpClient.PostAsync(url, httpContent).Result;
                    StatusCodeHandler(response);
                    if (response.IsSuccessStatusCode)
                    {
                        Task<string> t = response.Content.ReadAsStringAsync();
                        string s = t.Result;
    
                        result = JsonConvert.DeserializeObject<T>(s);
                    }
                }
                catch (Exception e)
                {
                    string msg = e.InnerException.InnerException.Message;
                    if (msg == "无法连接到远程服务器")
                    {
                        AlertUtil.Show("服务器无响应，请重新配置环境");
                        exceptionHandler("连接失败");
                    }
                }
                return result;
            }
    
    
            /// <summary>
            /// put请求
            /// </summary>
            /// <param name="url"></param>
            /// <param name="putData">put数据</param>
            /// <returns></returns>
            public static JObject PutResponse(string url, string putData = "")
            {
                if (string.IsNullOrEmpty(url))
                {
                    throw new ArgumentNullException("url");
                }
                if (url.StartsWith("https"))
                    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
    
                HttpContent httpContent = new StringContent(putData);
                httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
    
                HttpClient httpClient = new HttpClient();
                if (GlobalData.Authorization.Length > 0)
                {
                    httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                }
                try
                {
                    HttpResponseMessage response = httpClient.PutAsync(url, httpContent).Result;
                    StatusCodeHandler(response);
                    if (response.IsSuccessStatusCode)
                    {
                        string result = response.Content.ReadAsStringAsync().Result;
                        JObject jo = (JObject)JsonConvert.DeserializeObject(result);
                        return jo;
                    }
                }
                catch (Exception e)
                {
                    string msg = e.InnerException.InnerException.Message;
                    if (msg == "无法连接到远程服务器")
                    {
                        AlertUtil.Show("服务器无响应，请重新配置环境");
                        exceptionHandler("连接失败");
                    }
                }
                return new JObject();
            }
    
            /// <summary>
            /// delete请求
            /// </summary>
            /// <param name="url"></param>
            /// <returns></returns>
            public static JObject DeleteResponse(string url)
            {
                if (string.IsNullOrEmpty(url))
                {
                    throw new ArgumentNullException("url");
                }
                if (url.StartsWith("https"))
                    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
    
                HttpClient httpClient = new HttpClient();
                httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
    
                if (GlobalData.Authorization.Length > 0)
                {
                    httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                }
                try
                {
                    HttpResponseMessage response = httpClient.DeleteAsync(url).Result;
                    StatusCodeHandler(response);
                    string statusCode = response.StatusCode.ToString();
                    if (response.IsSuccessStatusCode)
                    {
                        string result = response.Content.ReadAsStringAsync().Result;
    
                        JObject jo = (JObject)JsonConvert.DeserializeObject(result);
                        return jo;
                    }
                }
                catch (Exception e)
                {
                    string msg = e.InnerException.InnerException.Message;
                    if (msg == "无法连接到远程服务器")
                    {
                        AlertUtil.Show("服务器无响应，请重新配置环境");
                        exceptionHandler("连接失败");
                    }
                }
                return new JObject();
            }
    
            private static void exceptionHandler(string msg)
            {
                throw new DyConnectException(msg);
            }
        }
    }

其中

if (GlobalData.Authorization.Length > 0)
                {
                    httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                }

是我登陆成功后返回的token，我把token放在header放在头部传给后台，如果具体业务不一样，可以修改。  
使用try…catch当连接后台不成功时抛出异常。  
DyConnectException是我自定义的一个异常类，用于处理连接后台不成功时的异常。  
DyConnectException.cs

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace DongliCAD
    {
        class DyConnectException : Exception
        {
            public int status = 911;
            public string message;
            public DyConnectException(string message)
            {
                this.message = message;
            }
        }
    }

其中Get和Post我提供了2种方式请求，一个是返回json格式的字段串，一个是解析成对象。

# 使用方法 #

## Get请求 ##

1.  返回json格式字符串，这个字符串解析成JObject对象，（JObject是Newtonsoft.Json里对象）

JObject jObject = HttpUtil.GetResponse("请求的url地址");

取数据方式：`jObject["code"].ToString()`或`jObject["code"]["code1"].ToString()`

1.  返回对象

ItemTypeRootVo itemTypeRootVo = HttpUtil.GetResponse<ItemTypeRootVo>("请求的url地址");

ItemTypeRootVo是我自定义的对象，比如如下

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace DongliCAD.vo
    {
        public class ItemTypeRootVo
        {
            /// <summary>
            /// 
            /// </summary>
            public int code { get; set; }
    
            /// <summary>
            /// 
            /// </summary>
            public string msg { get; set; }
    
            /// <summary>
            /// 
            /// </summary>
            public int error { get; set; }
    
            /// <summary>
            /// 
            /// </summary>
            public List<ItemTypeVo> data { get; set; }
        }
    
        public class ItemTypeVo
        {
            /// <summary>
            /// 
            /// </summary>
            public string uid { get; set; }
            /// <summary>
            /// 总装图
            /// </summary>
            public string itemTypeName { get; set; }
            /// <summary>
            /// 类型
            /// </summary>
            public string userTitle1 { get; set; }
            /// <summary>
            /// 中心高
            /// </summary>
            public string userTitle2 { get; set; }
            /// <summary>
            /// 总中心距
            /// </summary>
            public string userTitle3 { get; set; }
            /// <summary>
            /// 级数
            /// </summary>
            public string userTitle4 { get; set; }
            /// <summary>
            /// 输入轴轴径
            /// </summary>
            public string userTitle5 { get; set; }
            /// <summary>
            /// 输出轴轴径
            /// </summary>
            public string userTitle6 { get; set; }
            /// <summary>
            /// 输出力矩
            /// </summary>
            public string userTitle7 { get; set; }
            /// <summary>
            /// 
            /// </summary>
            public string userTitle8 { get; set; }
            /// <summary>
            /// 
            /// </summary>
            public int order { get; set; }
        }
    }

那么在请求成功后，会自动把json数据解析成ItemTypeRootVo对象，相对来说更方便些。

## Post请求 ##

1.  返回字符串请求，这种请求的get类似，同时post需要向后台传递数据。使用JObject或JArray。  
    比如传递对象

JObject jObj = new JObject();
                jObj.Add(new JProperty("userId", userName));
                jObj.Add(new JProperty("password", password));
                JObject result = HttpUtil.PostResponse("请求的url地址", jObj.ToString());

或者传递数组

JObject jObj = new JObject();
                JArray jArray = new JArray();
                jObj.Add(new JProperty("uid", workspaceCadInfoVo.itemRevUid));
                jObj.Add(new JProperty("ctype", "ITEMREVISION"));
                jArray.Add(jObj);
                JObject result = HttpUtil.PostResponse("请求的url地址", jArray.ToString());

1.  返回对象，同get一样。

# 扩展 #

## 文件上传 ##

有时候我们需要上传文件，同时也上传数据。方法如下，以异步方式上传

/// <summary>
            /// post请求
            /// </summary>
            /// <param name="url"></param>
            /// <param name="postData">post数据</param>
            /// <returns></returns>
            public static JObject PostFileResponse(string url, MultipartFormDataContent postData)
            {
                if (string.IsNullOrEmpty(url))
                {
                    throw new ArgumentNullException("url");
                }
                if (url.StartsWith("https"))
                    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
    
                //HttpContent httpContent = new FormCo StringContent(postData);
                //postData.Headers.ContentType = new MediaTypeHeaderValue("application/json");
                HttpClient httpClient = new HttpClient();
                if (GlobalData.Authorization.Length > 0)
                {
                    httpClient.DefaultRequestHeaders.Add("Authorization", GlobalData.Authorization);
                }
                try
                {
                    HttpResponseMessage response = httpClient.PostAsync(url, postData).Result;
                    StatusCodeHandler(response);
                    AuthorizationHandler(response, url);
                    if (response.IsSuccessStatusCode)
                    {
                        string result = response.Content.ReadAsStringAsync().Result;
                        JObject jo = (JObject)JsonConvert.DeserializeObject(result);
                        return jo;
                    }
                }
                catch (Exception e)
                {
                    string msg = e.InnerException.InnerException.Message;
                    if (msg == "无法连接到远程服务器")
                    {
                        AlertUtil.Show("服务器无响应，请重新配置环境");
                        exceptionHandler("连接失败");
                    }
                }
                return new JObject();
            }

**使用方式**

MultipartFormDataContent dataContent = new MultipartFormDataContent();
    		
    	    //传文件
                string pdfFileName = "test.pdf";
                FileStream pdfFsRead = new FileStream("D:/test/" + pdfFileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
                byte[] pdfBytes = new byte[(int)pdfFsRead.Length];
                pdfFsRead.Read(pdfBytes, 0, pdfBytes.Length);
                //ByteArrayContent pdfArrayContent = new ByteArrayContent(File.ReadAllBytes("D:/test/" + pdfFileName));
                ByteArrayContent pdfArrayContent = new ByteArrayContent(pdfBytes);
                pdfArrayContent.Headers.Add("Content-Type", "multipart/form-data");
                dataContent.Add(pdfArrayContent, "files", pdfFileName);
    
    		//传数据,注意格式是value-key,不是key-value
     	     dataContent.Add(new StringContent("123"), "itemRevisionUid");
                dataContent.Add("456", "datasetUid");
    		
    		//请求接口
    	   JObject jObject = HttpUtil.PostFileResponse("请求的url地址", dataContent);

上面将文件和数据都放到MultipartFormDataContent对象里.  
后台接口类似如下(使用kotlin语法写的。和java差不多)

/**
         * 保存图纸和pdf文档
         */
        @PostMapping("/saveDrawingno")
        fun saveDrawingno(
                          @RequestParam itemRevisionUid:Long,@RequestParam datasetUid: Long,
                          @RequestParam files: Array<MultipartFile>): ResponseEntity<Any> {
           
            //逻辑部分
        }

实现了即上传文件又上传数据的功能。

## 文件下载 ##

文件下载包括同步下载和异常下载。  
工具类HttpDownUtil.cs如下：

同步下载：HttpDownloadFile()  
异步下载：HttpDownloadFileAsyn()

使用方式也很简单

DownloadTmp downloadTmp = new DownloadTmp();
                downloadTmp.filePath = @“D:\test\666.txt”;
                HttpDownloadZip(downUrl, ref downloadTmp);

其中在外部我们也可以访问downloadTmp里的参数。谁让它用ref修饰呢