目的
通过一个简单的项目，在原来的文章基础上完善一下常用的几种WebApi编写方式以及请求方式，一方面是用于给我一个前端朋友用来学习调用接口，另一方面让我测试HttpClient的一些效果。
本文示例代码环境：vs2022、net6
准备
新创建了一个.Net WebAPI程序，安装组件
<ItemGroup> <PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="11.0.0" /> <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="6.0.1" /> <PackageReference Include="Swashbuckle.AspNetCore" Version="6.3.1" /> <PackageReference Include="Swashbuckle.AspNetCore.Newtonsoft" Version="6.3.1" /> </ItemGroup> ConfigureServices配置NewtonsoftJson以及Automapper和操作数据库代码(为了省事，删除了一些不影响当前效果的代码)
public void ConfigureServices(IServiceCollection services) { services.AddControllers().AddNewtonsoftJson(); services.AddEndpointsApiExplorer(); services.AddSwaggerGen(c => { c.SwaggerDoc("v1", new OpenApiInfo { Title = "MyWebApi", Version = "v1" }); }); //注入AutoMapper services.AddAutoMapper(Assembly.GetExecutingAssembly().DefinedTypes.Where(t => typeof(Profile).GetTypeInfo() .IsAssignableFrom(t.AsType())).Select(t => t.AsType()).ToArray()); } 注意：在Net core3.0以后，微软移除了Newtonsoft.Json，而使用了System.Text.Json，所以依赖于Newtonsoft.Json的组件将不可用，需要安装 Microsoft.AspNetCore.Mvc.NewtonsoftJson 包
因为仅仅作为演示，所以我只是新增一个控制器，里面包含了get、post、put、patch、delete几种类型的接口。这里先不贴代码，一点一点看。通过一个用户的添加、修改、删除作为一个演示的流程。
记得配置允许跨域请求，要不js请求会因为跨域问题而报错。详情看此处
数据来源就是控制器里面的一个静态变量，格式如下
public class UserDto { public long UserId { get; set; } public string Name { get; set; } public string Sex { get; set; } } 静态变量如下
private static readonly List<UserDto> _userDtoList = Enumerable.Range(0, 100) .Select(t => new UserDto { Name = "张三" + t, Sex = "男", UserId = 6974150586715897857 + t }).ToList(); 后端请求的方法我使用的是HttpClient，并且做成了一个公共类，部分需要用到的如下
public class HttpClientHelper: IHttpHelper { private readonly System.Net.Http.HttpClient _client; /// <summary> /// 构造函数 /// </summary> /// <param name="httpClientFactory"></param> public HttpClientHelper(IHttpClientFactory httpClientFactory) { _client = httpClientFactory.CreateClient(); } private void VerifyParam(string url, string jwtToken, IDictionary<string, string> headers) { _client.DefaultRequestHeaders.Clear(); if (string.IsNullOrWhiteSpace(url)) { throw new ArgumentNullException("url不能为null"); } if (!string.IsNullOrWhiteSpace(jwtToken)) { _client.DefaultRequestHeaders.Add("Authorization", $"Bearer {jwtToken}"); } if (headers?.Count > 0) { foreach (var (key, value) in headers) { _client.DefaultRequestHeaders.Add(key, value); } } } private static async Task<T> ConvertResponseResult<T>(HttpResponseMessage httpResponse) { //确保成功完成，不是成功就返回具体错误信息 httpResponse.EnsureSuccessStatusCode(); var resStr = await httpResponse.Content.ReadAsStringAsync(); if (typeof(T) == typeof(string)) return (T)Convert.ChangeType(resStr, typeof(string)); return JsonConvert.DeserializeObject<T>(resStr); } } 操作
请求头传递token只是为了演示请求头传递参数的写法，token为伪值
GET
从web服务检索数据。传递参数的本质是url字符串拼接，Request-Head头部传递，Request-Body中不能传递(严格点说不建议，因为我使用Apifox等工具可以在body中传值，swagger会提示 Request with GET/HEAD method cannot have body)
Query格式
编写用户id查询用户信息接口
[HttpGet("user/details")] public UserDto GetUserDetails(long userId) { if (!_userDtoList.Any(t => t.UserId == userId)) throw new ParameterException("未找到用户标识"); return _userDtoList.Find(t => t.UserId == userId); } 前端请求
$(function () { $.ajax({ type: "get", url: "http://localhost:5000/api/HttpSample/user/details?userId=6974150586715897857", headers: { "Authorization": "Bearer 123456" }, contentType: "application/json", success: function (data, status) { if (status == "success") { console.log(JSON.stringify(data)); } } }); var postdata = { userId: "6974150586715897857" }; $.ajax({ type: "get", headers:{"Authorization":"Bearer 123456"}, url: "http://localhost:5000/api/HttpSample/user/details", data: postdata, success: function (data, status) { if (status == "success") { console.log(JSON.stringify(data)); } } }); }); 后端请求
var token = "123456";//此处token是伪值 var result = await _httpHelper.GetAsync<ResultModel<UserDto>>("http://localhost:5000/api/HttpSample/user/details?userId=6974150586715897857", token); 这里的_httpHelper是注入的IHttpHelper(下面其他的方法一样)，对应的GetAsync为
public async Task<T> GetAsync<T>(string url, string jwtToken = "", IDictionary<string, string> headers = null) { VerifyParam(url, jwtToken, headers); var response = await _client.GetAsync(url).ConfigureAwait(false); return await ConvertResponseResult<T>(response).ConfigureAwait(false); } 接口工具请求
url：http://localhost:5000/api/HttpSample/user/details?userId=6974150586715897857
并且再请求头增加：Authorization，值为Bearer xxxx
返回结果如下
POST
在web服务上创建新的数据项。约定用于向服务端提交数据操作，请求时候参数放在参数FromBody传递
Json格式
演示添加用户操作
请求类
public class UserDto { public long UserId { get; set; } public string Name { get; set; } public string Sex { get; set; } } 接口代码示例
[HttpPost("user/add")] public bool Add([FromBody] UserDto request) { if (_userDtoList.Any(t => t.UserId == request.UserId)) throw new ParameterException("用户标识已经存在"); Console.WriteLine(DateTime.Now + " " + HttpContext.Request.Headers["Authorization"].FirstOrDefault()); _userDtoList.Add(request); return true; } 前端请求
$(function () { var param = { userId: "8974150586715897867", name: "老八", sex: "女" }; $.ajax({ type: "post", dataType: 'json', contentType: "application/json", headers: { "Authorization": "Bearer 123456" }, url: "http://localhost:5000/api/HttpSample/user/add", data: JSON.stringify(param), success: function (data) { if (status == "success") { console.log(JSON.stringify(data)); } } }); }); 后端请求
var token = "123456";//此处token是伪值 var url = "http://localhost:5000/api/HttpSample/user/add"; var usedto = new UserDto { UserId = 123456, Name = "李四", Sex = "女" }; var result = await _httpHelper.PostAsync<ResultModel<bool>>(url, usedto, token); public async Task<T> PostAsync<T>(string url, object data, string jwtToken = "", IDictionary<string, string> headers = null) { VerifyParam(url, jwtToken, headers); var jsonData = data is string ? data.ToString() : JsonConvert.SerializeObject(data); using var content = new StringContent(jsonData ?? string.Empty, Encoding.UTF8, "application/json"); var response = await _client.PostAsync(url, content).ConfigureAwait(false); return await ConvertResponseResult<T>(response).ConfigureAwait(false); } 接口工具请求
传递参数格式为json格式，请求头部默认添加："Content-Type", "application/json"
x-www-form-unlencoded格式
更新用户姓名
[HttpPost("user/updatename")] public bool UpdateName([FromForm] long userId, [FromForm] string name) { var entity = _userDtoList.Find(t => t.UserId == userId); if (entity is null) throw new ParameterException("用户标识不存在"); entity.Name = name; return true; } 前端请求
$(function () { var postdata = { userId: "6974150586715897857", name: "赵六" }; $.ajax({ type: "post", headers: { "Authorization": "Bearer 123456" }, url: "http://localhost:5000/api/HttpSample/user/updatename", data: postdata, success: function (data, status) { if (status == "success") { console.log(JSON.stringify(data)); } } }); }); 后端请求
var token = "123456";//此处token是伪值 var url = "http://localhost:5000/api/HttpSample/user/updatename"; var dic = new Dictionary<string, string> { { "userId","6974150586715897857"}, { "name","王五"} }; var result = await _httpHelper.PostFormDataAsync<ResultModel<bool>>(url, dic, token); public async Task<T> PostFormDataAsync<T>(string url, Dictionary<string, string> data, string jwtToken = "", IDictionary<string, string> headers = null) { VerifyParam(url, jwtToken, headers); var httpContent = new FormUrlEncodedContent(data); var response = await _client.PostAsync(url, httpContent).ConfigureAwait(false); return await ConvertResponseResult<T>(response).ConfigureAwait(false); } 接口工具请求
选择post请求，参数在Body，然后选择x-www-form-unlencoded格式。
Form-data格式
模拟上传用户头像操作
[HttpPost("user/uploadImg")] public string Upload([FromForm] IFormFile img, [FromForm] long userId) { if (img is null) throw new ParameterException("用户头像不能为null"); Console.WriteLine(HttpContext.Request.Headers["Authorization"].FirstOrDefault()); var entity = _userDtoList.Find(t => t.UserId == userId); if (entity is null) throw new ParameterException("用户标识不存在"); return img.FileName; } 注意：当你上传大于30000000字节长度的文件时候，需要修改上传文件的默认限制
前端请求
$(function () { $("#tijiao").click(function () { //logoimg是<input type="file" id="logoimg"" /> var files = $("#logoimg").prop('files'); //获取到文件列表 var formData = new FormData(); formData.append("userId", "6974150586715897857"); formData.append("img", files[0], "1122.jpg");//图片文件流 console.log(formData); $.ajax({ type: 'post', url: "http://localhost:5000/api/HttpSample/user/uploadImg", headers: { "Authorization": "Bearer 123456" }, mimeType: "multipart/form-data", processData: false, contentType: false, data: formData, success: function (data) { //后端Httpclient请求成功后返回过来的结果 console.log(data); } }); }); }); 后端请求
var url = "http://localhost:5000/api/HttpSample/user/uploadImg"; var formData = new MultipartFormDataContent(); var bytes = System.IO.File.ReadAllBytes("D:\Downloads\11111.jpg"); var byteContent = new ByteArrayContent(bytes); byteContent.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("form-data") { Name = "img", FileName = "111.jpg" }; formData.Add(byteContent); // 写法一 formData.Add(new StringContent("6974150586715897857"), "userId"); // 写法二 var byteContent2 = new ByteArrayContent(Encoding.UTF8.GetBytes("天气")); byteContent2.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("form-data") { Name = "name", }; formData.Add(byteContent2); var headerDic = new Dictionary<string, string> { { "Authorization","Bearer 123456"}, }; var result = await _httpHelper.PostFormDataAsync<ResultModel<string>>(url, formData, headerDic); public async Task<T> PostFormDataAsync<T>(string url, MultipartFormDataContent data, IDictionary<string, string> headers = null) { VerifyParam(url, "", headers); var result = await _client.PostAsync(url, data).ConfigureAwait(false); return await ConvertResponseResult<T>(result); } 接口工具请求
选择Body=>form-data
PUT
更新web服务上的数据项。
Json格式
更新用户信息
[HttpPut("user/update")] public bool Update(UserDto userDto) { if (userDto is null) throw new ParameterException("参数不能为空"); Console.WriteLine(DateTime.Now + " " + HttpContext.Request.Headers["Authorization"].FirstOrDefault()); var currUser = _userDtoList.Find(t => t.UserId == userDto.UserId); if (currUser is null) throw new ParameterException("用户标识不存在"); currUser.Name = userDto.Name; currUser.Sex = userDto.Sex; return true; } 前端请求
$(function () { var param = { userId: "6974150586715897859", name: "老八", sex: "女" }; $.ajax({ type: "put", dataType: 'json', contentType: "application/json", headers: { "Authorization": "Bearer 123456" }, url: "http://localhost:5000/api/HttpSample/user/update", data: JSON.stringify(param), success: function (data, status) { if (status == "success") { console.log(JSON.stringify(data)); } } }); }); 后端请求
var token = "123456";//此处token是伪值 var usedto = new UserDto { UserId = 6974150586715897859, Name = "老八", Sex = "女" }; var url = "http://localhost:5000/api/HttpSample/user/update"; var result = await _httpHelper.PutAsync<ResultModel<bool>>(url, usedto, token); return JsonConvert.SerializeObject(result); public async Task<T> PutAsync<T>(string url, object data, string jwtToken = "", IDictionary<string, string> headers = null) { VerifyParam(url, jwtToken, headers); var jsonData = data is string ? data.ToString() : JsonConvert.SerializeObject(data); using var content = new StringContent(jsonData ?? string.Empty, Encoding.UTF8, "application/json"); var response = await _client.PutAsync(url, content).ConfigureAwait(false); return await ConvertResponseResult<T>(response).ConfigureAwait(false); } 接口工具请求
URL：http://localhost:5000/api/HttpSample/user/update
参数传递：Body=>json
DELETE
删除web服务上的数据项。
Query格式
删除用户信息
[HttpDelete("user")] public bool Delete(long userId) { var entity = _userDtoList.Find(t => t.UserId == userId); if (entity is null) throw new ParameterException("用户标识不存在"); Console.WriteLine(DateTime.Now + " " + HttpContext.Request.Headers["Authorization"].FirstOrDefault()); _userDtoList.Remove(entity); return true; } 前端请求
$(function () { $.ajax({ type: "DELETE", url: "http://localhost:5000/api/HttpSample/user?userId=6974150586715897861", headers: { "Authorization": "Bearer 123456" }, success: function (data, status) { if (status == "success") { console.log(JSON.stringify(data)); } } }); }); 后端请求
var token = "123456";//此处token是伪值 var url = "http://localhost:5000/api/HttpSample/user?userId=6974150586715897862"; var result = await _httpHelper.DeleteAsync<ResultModel<bool>>(url, token); public async Task<T> DeleteAsync<T>(string url, string jwtToken = "", IDictionary<string, string> headers = null) { VerifyParam(url, jwtToken, headers); var response = await _client.DeleteAsync(url).ConfigureAwait(false); return await ConvertResponseResult<T>(response).ConfigureAwait(false); } 接口工具请求
URL：http://localhost:5000/api/HttpSample/user?userId=6974150586715897859
Patch
通过描述有关如何修改项的一组说明，更新web服务上的数据项。
请求格式如下：
[{"op" : "replace", "path" : "/PassWord", "value" : "222222"}]
op属性指示操作的类型，path属性指示要更新的元素，value属性提供新值。
add：添加属性或数组元素。 对于现有属性：设置值。
remove：删除属性或数组元素。
replace：替换操作
为了支持该请求方式，需要安装nuget包Microsoft.AspNetCore.Mvc.NewtonsoftJson。
参考文档：https://docs.microsoft.com/zh-cn/aspnet/core/web-api/jsonpatch?view=aspnetcore-6.0
Json格式
在此用于更新数据
[HttpPatch("user/update2/{userId}")] public UserDto Update2([FromRoute] long userId, JsonPatchDocument<UserDto> jsonPatch, [FromServices] IMapper mapper) { var entity = _userDtoList.Find(t => t.UserId == userId); if (entity is null) throw new ParameterException("用户标识无效"); var dto = mapper.Map<UserDto>(entity); jsonPatch.ApplyTo(dto, ModelState); var user = _userDtoList.Find(t => t.UserId == userId); mapper.Map(dto, user); return user; } 前端请求
演示根据用户id去更新用户的姓名
$(function () { var par = [{ "op": "replace", "path": "/name", "value": "老六" }]; $.ajax({ type: "Patch", url: "http://localhost:5000/api/HttpSample/user/update2/6974150586715897857", headers: { "Authorization": "Bearer 123456" }, contentType: "application/json", data: JSON.stringify(par), success: function (result) { console.log(result); } }); }); 后端请求
var token = "123456";//此处token是伪值 var url = "http://localhost:5000/api/HttpSample/user/update2/6974150586715897859"; var content = "[{"op":"replace","path":"/name","value":"小七七"}]"; var result = await _httpHelper.PatchAsync<ResultModel<UserDto>>(url, content, token); public async Task<T> PatchAsync<T>(string url, object data, string jwtToken = "", IDictionary<string, string> headers = null) { VerifyParam(url, jwtToken, headers); var jsonData = data is string ? data.ToString() : JsonConvert.SerializeObject(data); using var content = new StringContent(jsonData ?? string.Empty, Encoding.UTF8, "application/json"); var response = await _client.PatchAsync(url, content).ConfigureAwait(false); return await ConvertResponseResult<T>(response).ConfigureAwait(false); } 接口工具请求
参数传递：Body=>json
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