{ "cells": [ { "cell_type": "markdown", "metadata": { "dotnet_interactive": { "language": "csharp" }, "polyglot_notebook": { "kernelName": "csharp" } }, "source": [ "# 基础使用-发送请求" ] }, { "cell_type": "markdown", "metadata": { "dotnet_interactive": { "language": "csharp" }, "polyglot_notebook": { "kernelName": "csharp" }, "vscode": { "languageId": "polyglot-notebook" } }, "source": [ "## 0、初始化与全局设置" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "dotnet_interactive": { "language": "csharp" }, "polyglot_notebook": { "kernelName": "csharp" }, "vscode": { "languageId": "polyglot-notebook" } }, "outputs": [], "source": [ "//全局设置，行运行一次，为后续准备\n", "#r \"nuget:System.Net.Http.Json\"\n", "#r \"nuget:Microsoft.Net.Http.Headers\"\n", "#r \"nuget:Microsoft.Extensions.Http\"\n", "#r \"nuget:Microsoft.Extensions.DependencyInjection\"\n", "#r \"./Publish/HttpClientStudy.Model/HttpClientStudy.Model.dll\"\n", "#r \"./Publish/HttpClientStudy.Core/HttpClientStudy.Core.dll\"\n", "\n", "global using System;\n", "global using System.Collections;\n", "global using System.Collections.Concurrent;\n", "global using System.Linq;\n", "global using System.Linq.Expressions;\n", "global using System.Threading;\n", "global using System.Threading.Tasks;\n", "global using System.Net.Http;\n", "//System.Net.Http.Json 包含处理json的扩展方法，方便处理请求和影响中的json数据\n", "global using System.Net.Http.Json;\n", "global using Microsoft.Extensions.DependencyInjection;\n", "global using Microsoft.Extensions.DependencyInjection.Extensions;\n", "\n", "global using HttpClientStudy.Config;\n", "global using HttpClientStudy.Core;\n", "global using HttpClientStudy.Core.Utilities;\n", "\n", "//全局变量\n", "var webApiBaseUrl = WebApiConfigManager.GetWebApiConfig().BaseUrl;\n", "var workDir = Environment.CurrentDirectory;\n", "var fullPath = System.IO.Path.GetFullPath(\"./Publish/HttpClientStudy.WebApp/HttpClientStudy.WebApp.exe\", workDir);\n", "\n", "//全局共享静态 HttpClient 对象\n", "public static HttpClient SharedClient = new HttpClient(new SocketsHttpHandler(){ PooledConnectionIdleTimeout = TimeSpan.FromSeconds(30)})\n", "{\n", " BaseAddress = new Uri(WebApiConfigManager.GetWebApiConfig().BaseUrl),\n", "};\n", "\n", "//启动已发布的WebApi项目\n", "{\n", " Console.WriteLine(\"启动WebApi项目\");\n", " var startMessage = AppUtility.RunWebApiExeFile(fullPath);\n", " Console.WriteLine(startMessage);\n", "}" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 1、创建HttpClient" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "根据 系列教程的 `管理客户端` 一章, 创建的HttpClient对象，有非常多的方式。\n", "为方便演示，本节使用两种：一种是全局共享对象(SharedClient, 在初始化时创建), 符合共享的使用原则; 一种是临时实例化对象。" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## 2、发出 Http请求" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Http 简介" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "http是无状态的请求/响应模式。\n", "\n", "客户端请求: 请求行(方法 URL 协议版本 回车换行符)、请求头、空行及可选的请求体；\n", "\n", "![客户端请求消息](./Assets/RequestMessage.png)\n", "\n", "服务器响应：状态行(协议版本 状态码 状态码描述 回车换行符)、响应头及可选的响应体。\n", "\n", "![客户端请求消息](./Assets/ResponseMessage.jpg)\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Http 请求方法" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Http请求方法可通过多种特性区分：\n", "\n", "1. 谓词：也就是请求方法，Post、Get、Put、Delete、Options、Head等；\n", "2. 幂等性：如果可多次成功处理某个请求方法而不改变结果，则该请求方法是幂等的；\n", "3. 可缓存性：如果可以存储请求方法的相应响应以供重复使用，则该请求方法是可缓存的；\n", "4. 安全性：如果请求方法不会修改资源的状态，则被视为安全方法。所有安全方法也都是幂等方法，但并非所有幂等方法都是安全方法；\n", "\n", " | **HTTP 方法** | **是否是幂等的** | **是否可缓存** | **是否安全** |\n", " | ------------- | ---------------- | -------------- | ------------ |\n", " | `GET` | ✔️ 是 | ✔️ 是 | ✔️ 是 |\n", " | `POST` | ❌ 否 | ⚠️ †很少 | ❌ 否 |\n", " | `PUT` | ✔️ 是 | ❌ 否 | ❌ 否 |\n", " | `PATCH` | ❌ 否 | ❌ 否 | ❌ 否 |\n", " | `DELETE` | ✔️ 是 | ❌ 否 | ❌ 否 |\n", " | `HEAD` | ✔️ 是 | ✔️ 是 | ✔️ 是 |\n", " | `OPTIONS` | ✔️ 是 | ❌ 否 | ✔️ 是 |\n", " | `TRACE` | ✔️ 是 | ❌ 否 | ✔️ 是 |\n", " | `CONNECT` | ❌ 否 | ❌ 否 | ❌ 否 |\n", "> \n", ">†仅当存在相应的 Cache-Control 或 Expires 响应标头时，POST 方法才可缓存。 这在实践中非常罕见。" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Http 状态码" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Http 状态码是响应的首要标识，指定响应的不同结果，分为以下几类：\n", "\n", "1. 1xx：信息，表示临时响应，大多数临时响应 (例如 HttpStatusCode.Continue) 使用 HttpClient 在内部处理，并且永远不会显示给用户；\n", "2. 2xx：成功，表示请求已被成功接收、理解、并接受；\n", "3. 3xx：重定向，表示需要完成一个或多个附加步骤才能完成请求，自动重定向默认处于打开状态，可以使用 HttpClientHandler.AllowAutoRedirect 或 SocketsHttpHandler.AllowAutoRedirect 进行更改；\n", "4. 4xx：客户端错误，表示客户端的请求无效(请求包含语法错误或无法完成请求)；\n", "5. 5xx：服务器错误，表示服务器在处理请求的过程中发生了错误。" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### 使用 HttpClient 发出请求" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "要发出 HTTP 请求，请调用以下任一 API：\n", "\n", "| HTTP 方法 | API |\n", "| ----------------- | ---------------------------- |\n", "| `GET` | HttpClient.GetAsync |\n", "| `GET` | HttpClient.GetByteArrayAsync |\n", "| `GET` | HttpClient.GetStreamAsync |\n", "| `GET` | HttpClient.GetStringAsync |\n", "| `POST` | HttpClient.PostAsync |\n", "| `PUT` | HttpClient.PutAsync |\n", "| `PATCH` | HttpClient.PatchAsync |\n", "| `DELETE` | HttpClient.DeleteAsync |\n", "| †`USER SPECIFIED` | HttpClient.SendAsync |\n", "\n", "
\n", "\n", "> †USER SPECIFIED 请求指示 SendAsync 方法接受任何有效的 HttpMethod。" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Http 内容" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "HttpContent 类型用于表示 HTTP 实体正文和相应的内容标头。 对于需要正文的 HTTP 方法（或请求方法）POST、PUT 和 PATCH，可使用 HttpContent 类来指定请求的正文。\n", "大多数示例演示如何使用 JSON 有效负载准备 StringContent 子类，但还有针对其他内容 (MIME) 类型的其他子类。\n", "\n", "- ByteArrayContent：提供基于字节数组的 HTTP 内容；\n", "- FormUrlEncodedContent：为使用 \"application/x-www-form-urlencoded\" MIME 类型编码的名称/值元组提供 HTTP 内容；\n", "- JsonContent：提供基于 JSON 的 HTTP 内容；\n", "- MultipartContent：提供使用 \"multipart/*\" MIME 类型规范进行序列化的 HttpContent 对象的集合；\n", "- MultipartFormDataContent：为使用 \"multipart/form-data\" MIME 类型进行编码的内容提供容器；\n", "- ReadOnlyMemoryContent：提供基于 ReadOnlyMemory 的 HTTP 内容；\n", "- StreamContent：提供基于流的 HTTP 内容；\n", "- StringContent：提供基于字符串的 HTTP 内容\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Http Get" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "GET 请求不应发送正文，而是用于从资源检索数据。 要在给定 HttpClient 和 URI 的情况下发出 HTTP GET 请求，推荐使用 HttpClient.GetAsync 方法。\n", "\n", "> Get 请求，一般不会发送数据（服务器支持的话，也能带），最大特点是：可以缓存请求结果,减少服务器压力。" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "vscode": { "languageId": "polyglot-notebook" } }, "outputs": [], "source": [ "//Get 请求\n", "{\n", " //使用共享客户端发送Get请求\n", " var response = await SharedClient.GetAsync(\"/api/hello/index\");\n", "\n", " //确保请求成功\n", " response.EnsureSuccessStatusCode();\n", "\n", " //读取响应内容\n", " var content = await response.Content.ReadAsStringAsync();\n", "\n", " //输出 响应内容\n", " Console.WriteLine(content);\n", "}" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##　Http Get Json" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "System.Net.Http.Json 库，为请求Json格式数据和接受json格式数据提供了很多扩展方法，使用 HttpClient 发送和请求Json格式数据非常方便; \n", "后面单独章节讲解，这里只是一个例子." ] }, { "cell_type": "code", "execution_count": null, "metadata": { "vscode": { "languageId": "polyglot-notebook" } }, "outputs": [], "source": [ "/*\n", " Get Json\n", " 需要先引入 System.Net.Http.Json 和 命名空间(全局设置里已完成)\n", "*/\n", "{\n", "\n", " //使用共享客户端发送Get请求\n", " var content = await SharedClient.GetFromJsonAsync(\"/api/hello/GetAccount\");\n", "\n", " //框架显示方法\n", " content.Display();\n", "}" ] } ], "metadata": { "kernelspec": { "display_name": ".NET (C#)", "language": "C#", "name": ".net-csharp" }, "language_info": { "name": "python" }, "polyglot_notebook": { "kernelInfo": { "defaultKernelName": "csharp", "items": [ { "aliases": [], "name": "csharp" } ] } } }, "nbformat": 4, "nbformat_minor": 2 }