.Net之接口小知識

目的

通過一個簡單的項目，在原來的文章基礎上完善一下常用的幾種WebApi編寫方式以及請求方式，一方面是用於給我一個前端朋友用來學習調用接口，另一方面讓我測試HttpClient的一些效果。

本文示例代碼環境：vs2022、net6

準備

新創建了一個.Net WebAPI程序，安裝組件

<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和操作數據庫代碼(爲了省事，刪除了一些不影響當前效果的代碼)

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以後，微軟移除了Newtonsoft.Json，而使用了System.Text.Json，所以依賴於Newtonsoft.Json的組件將不可用，需要安裝 Microsoft.AspNetCore.Mvc.NewtonsoftJson 包

因爲僅僅作爲演示，所以我只是新增一個控制器，裏面包含了get、post、put、patch、delete幾種類型的接口。這裏先不貼代碼，一點一點看。通過一個用戶的添加、修改、刪除作爲一個演示的流程。

記得配置允許跨域請求，要不js請求會因爲跨域問題而報錯。詳情看此處

數據來源就是控制器裏面的一個靜態變量，格式如下

public class UserDto
{
    public long UserId { get; set; }

    public string Name { get; set; }

    public string Sex { get; set; }
}

靜態變量如下

private static readonly List<UserDto> _userDtoList = Enumerable.Range(0, 100)
        .Select(t => new UserDto
        {
            Name = "張三" + t,
            Sex = "男",
            UserId = 6974150586715897857 + t
        }).ToList();

後端請求的方法我使用的是HttpClient，並且做成了一個公共類，部分需要用到的如下

public class HttpClientHelper: IHttpHelper
{
    private readonly System.Net.Http.HttpClient _client;

    /// <summary>
    /// 構造函數
    /// </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不能爲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)
    {
        //確保成功完成，不是成功就返回具體錯誤信息
        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

請求頭傳遞token只是爲了演示請求頭傳遞參數的寫法，token爲僞值

GET

從web服務檢索數據。傳遞參數的本質是url字符串拼接，Request-Head頭部傳遞，Request-Body中不能傳遞(嚴格點說不建議，因爲我使用Apifox等工具可以在body中傳值，swagger會提示 Request with GET/HEAD method cannot have body)

Query格式

編寫用戶id查詢用戶信息接口

[HttpGet("user/details")]
public UserDto GetUserDetails(long userId)
{
    if (!_userDtoList.Any(t => t.UserId == userId))
        throw new ParameterException("未找到用戶標識");
    return _userDtoList.Find(t => t.UserId == userId);
}

前端請求

$(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));
            }  
        }
    });
});

後端請求

var token = "123456";//此處token是僞值
var result = await _httpHelper.GetAsync<ResultModel<UserDto>>("http://localhost:5000/api/HttpSample/user/details?userId=6974150586715897857", token);

這裏的_httpHelper是注入的IHttpHelper(下面其他的方法一樣)，對應的GetAsync爲

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);
}

接口工具請求

url：http://localhost:5000/api/HttpSample/user/details?userId=6974150586715897857

並且再請求頭增加：Authorization，值爲Bearer xxxx

返回結果如下

POST

在web服務上創建新的數據項。約定用於向服務端提交數據操作，請求時候參數放在參數FromBody傳遞

Json格式

演示添加用戶操作

請求類

public class UserDto
{
    public long UserId { get; set; }

    public string Name { get; set; }

    public string Sex { get; set; }
}

接口代碼示例

[HttpPost("user/add")]
public bool Add([FromBody] UserDto request)
{
    if (_userDtoList.Any(t => t.UserId == request.UserId))
        throw new ParameterException("用戶標識已經存在");
    Console.WriteLine(DateTime.Now + "   " + HttpContext.Request.Headers["Authorization"].FirstOrDefault());
    _userDtoList.Add(request);
    return true;
}

前端請求

$(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));
            }
        }
    });
});

後端請求

var token = "123456";//此處token是僞值
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);
}

接口工具請求

傳遞參數格式爲json格式，請求頭部默認添加："Content-Type", "application/json"

x-www-form-unlencoded格式

更新用戶姓名

[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("用戶標識不存在");

    entity.Name = name;

    return true;
}

前端請求

$(function () {
    var postdata = { userId: "6974150586715897857", name: "趙六" };
    $.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));
            }
        }
    });
});

後端請求

var token = "123456";//此處token是僞值
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);
}

接口工具請求

選擇post請求，參數在Body，然後選擇x-www-form-unlencoded格式。

Form-data格式

模擬上傳用戶頭像操作

[HttpPost("user/uploadImg")]
public string Upload([FromForm] IFormFile img, [FromForm] long userId)
{
    if (img is null)
        throw new ParameterException("用戶頭像不能爲null");

    Console.WriteLine(HttpContext.Request.Headers["Authorization"].FirstOrDefault());
    var entity = _userDtoList.Find(t => t.UserId == userId);
    if (entity is null)
        throw new ParameterException("用戶標識不存在");

    return img.FileName;
}

注意：當你上傳大於30000000字節長度的文件時候，需要修改上傳文件的默認限制

前端請求

$(function () {
    $("#tijiao").click(function () {
        //logoimg是<input type="file" id="logoimg"" />
        var files = $("#logoimg").prop('files'); //獲取到文件列表

        var formData = new FormData();
        formData.append("userId", "6974150586715897857");
        formData.append("img", files[0], "1122.jpg");//圖片文件流

        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) {
                //後端Httpclient請求成功後返回過來的結果
                console.log(data);
            }
        });
    });
});

後端請求

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);

// 寫法一
formData.Add(new StringContent("6974150586715897857"), "userId");

// 寫法二
var byteContent2 = new ByteArrayContent(Encoding.UTF8.GetBytes("天氣"));
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);
}

接口工具請求

選擇Body=>form-data

PUT

更新web服務上的數據項。

Json格式

更新用戶信息

[HttpPut("user/update")]
public bool Update(UserDto userDto)
{
    if (userDto is null)
        throw new ParameterException("參數不能爲空");

        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("用戶標識不存在");

    currUser.Name = userDto.Name;
    currUser.Sex = userDto.Sex;
    return true;
}

前端請求

$(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));
            }
        }
    });
});

後端請求

var token = "123456";//此處token是僞值

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);
}

接口工具請求

URL：http://localhost:5000/api/HttpSample/user/update

參數傳遞：Body=>json

DELETE

刪除web服務上的數據項。

Query格式

刪除用戶信息

[HttpDelete("user")]
public bool Delete(long userId)
{
    var entity = _userDtoList.Find(t => t.UserId == userId);
    if (entity is null)
        throw new ParameterException("用戶標識不存在");

    Console.WriteLine(DateTime.Now + "    " + HttpContext.Request.Headers["Authorization"].FirstOrDefault());
    _userDtoList.Remove(entity);
    return true;
}

前端請求

$(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));
            }
        }
    });
});

後端請求

var token = "123456";//此處token是僞值
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);
}

接口工具請求

URL：http://localhost:5000/api/HttpSample/user?userId=6974150586715897859

Patch

通過描述有關如何修改項的一組說明，更新web服務上的數據項。

請求格式如下：

[{"op" : "replace", "path" : "/PassWord", "value" : "222222"}]

op屬性指示操作的類型，path屬性指示要更新的元素，value屬性提供新值。

add：添加屬性或數組元素。 對於現有屬性：設置值。

remove：刪除屬性或數組元素。

replace：替換操作

爲了支持該請求方式，需要安裝nuget包Microsoft.AspNetCore.Mvc.NewtonsoftJson。

參考文檔：https://docs.microsoft.com/zh-cn/aspnet/core/web-api/jsonpatch?view=aspnetcore-6.0

Json格式

在此用於更新數據

[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("用戶標識無效");

    var dto = mapper.Map<UserDto>(entity);
    jsonPatch.ApplyTo(dto, ModelState);

    var user = _userDtoList.Find(t => t.UserId == userId);
    mapper.Map(dto, user);
    return user;
}

前端請求

演示根據用戶id去更新用戶的姓名

$(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);
        }
    });
});

後端請求

var token = "123456";//此處token是僞值
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);
}

接口工具請求

參數傳遞：Body=>json