.Net Core webapi RestFul 统一接口数据返回格式

在RestFul风格盛行的年代，大部分接口都需要一套统一的数据返回格式，那么我们怎么才能保证使用统一的json数据格式返回呢，下面给大家简单介绍一下：

假如我们需要接口统一返回一下数据格式：

{"statusCode": 200,"successful": true,"message": null,"data": object
}

json对象中data是返回的实际结果对象，可以是一个对象、一个list、一个字符串、一个数字......

但是整体的json格式要以上面的为准

一般这种情况我们有两种实现方式：

1、自定义一个统一返回类

2、使用过滤器(Filter)实现

下面先介绍第一种，自定义一个接口返回类：

创建对应的接口类和实现类

ApiResponse.cs//实现类
IApiResponse.cs://几个相关的接口

IApiResponse.cs

    public interface IApiResponse{public int StatusCode { get; set; }public bool Successful { get; set; }public string? Message { get; set; }}public interface IApiResponse<T> : IApiResponse{public T? Data { get; set; }}public interface IApiErrorResponse{public Dictionary<string, object> ErrorData { get; set; }}

保证了所有相关对象都来自 IApiResponse 接口

ApiResponse.cs

    public class ApiResponse<T> : IApiResponse<T>{public ApiResponse(){}public ApiResponse(T? data){Data = data;}public int StatusCode { get; set; } = 200;public bool Successful { get; set; } = true;public string? Message { get; set; }public T? Data { get; set; }/// <summary>/// 实现将 <see cref="ApiResponse"/> 隐式转换为 <see cref="ApiResponse{T}"/>/// </summary>/// <param name="apiResponse"><see cref="ApiResponse"/></param>public static implicit operator ApiResponse<T>(ApiResponse apiResponse){return new ApiResponse<T>{StatusCode = apiResponse.StatusCode,Successful = apiResponse.Successful,Message = apiResponse.Message};}}public class ApiResponse : IApiResponse, IApiErrorResponse{public int StatusCode { get; set; } = 200;public bool Successful { get; set; } = true;public string? Message { get; set; }public object? Data { get; set; }/// <summary>/// 可序列化的错误/// <para>用于保存模型验证失败的错误信息</para>/// </summary>public Dictionary<string, object>? ErrorData { get; set; }public ApiResponse(){}public ApiResponse(object data){Data = data;}public static ApiResponse NoContent(string message = "NoContent"){return new ApiResponse{StatusCode = StatusCodes.Status204NoContent,Successful = true,Message = message};}public static ApiResponse Ok(string message = "Ok"){return new ApiResponse{StatusCode = StatusCodes.Status200OK,Successful = true,Message = message};}public static ApiResponse Ok(object data, string message = "Ok"){return new ApiResponse{StatusCode = StatusCodes.Status200OK,Successful = true,Message = message,Data = data};}public static ApiResponse Unauthorized(string message = "Unauthorized"){return new ApiResponse{StatusCode = StatusCodes.Status401Unauthorized,Successful = false,Message = message};}public static ApiResponse NotFound(string message = "NotFound"){return new ApiResponse{StatusCode = StatusCodes.Status404NotFound,Successful = false,Message = message};}public static ApiResponse BadRequest(string message = "BadRequest"){return new ApiResponse{StatusCode = StatusCodes.Status400BadRequest,Successful = false,Message = message};}public static ApiResponse BadRequest(ModelStateDictionary modelState, string message = "ModelState is not valid."){return new ApiResponse{StatusCode = StatusCodes.Status400BadRequest,Successful = false,Message = message,ErrorData = new SerializableError(modelState)};}public static ApiResponse Error(string message = "Error", Exception? exception = null){object? data = null;if (exception != null){data = new{exception.Message,exception.Data};}return new ApiResponse{StatusCode = StatusCodes.Status500InternalServerError,Successful = false,Message = message,Data = data};}}

分别实现类带有泛型的 ApiResponse<T> 类和 ApiResponse 类

注意在泛型类中，使用运算符重载，实现了 ApiResponse 到 ApiResponse<T> 的隐式转换。

在接口实现处返回一个 ApiResponse<T> 对象：

        [HttpGet]public ApiResponse<UserEntity> Get(string name){var list = new List<UserEntity>() {new UserEntity() { Name = "张三" },new UserEntity(){Name = "李四"}};var user = list.Find(p => p.Name == name);return user == null ? ApiResponse.NotFound() : new ApiResponse<UserEntity>(user);}

注意看最后一句