前言
代码胡乱写，维护火葬场！
在平时工作中遇到前同事写接口这样返回值
当接口返回1时，不去看他的代码就永远猜不到这个1代表的是返回成功还是返回值
稍微好点的
维护和改bug简直让人疯狂，导致大部分时间浪费在“体会”别人返回值的逻辑中
天天加班与救bug于水火之中
合理分配前后端返回值很重要！
一般我们常用统一的格式返回json,无论后台是运行正常还是发生异常，响应给前端的数据格式是不变的！
public class Result<T> where T : class
{
public ResultCode code { get; set; }
public string msg { get; set; }
public T data { get; set; }
}
包装一下，通常使用构造函数
public class Result<T> where T : class
{
public ResultCode code { get; set; }
public string msg { get; set; }
public T data { get; set; }
public Result(T data)
{
code = ResultCode.Ok;
msg = ResultCode.Ok.GetDescription();
this.data = data;
}
public Result(ResultCode code, string msg, T data)
{
this.code = code;
this.msg = msg ?? code.GetDescription();
this.data = data;
}
}
这么使用new Result<Store>(code, msg, data)使用起来还是不够简化
继续封装
public class Result<T> where T : class
{
public ResultCode code { get; set; }
public string msg { get; set; }
public T data { get; set; }
public Result(T data)
{
code = ResultCode.Ok;
msg = ResultCode.Ok.GetDescription();
this.data = data;
}
public Result(ResultCode code, string msg, T data)
{
this.code = code;
this.msg = msg ?? code.GetDescription();
this.data = data;
}
public static Result<T> FromCode(ResultCode code, string msg = null, T data = default)
{
if (data == null)
data = (T) new Object();
return new Result<T>(code, msg, data);
}
public static Result<T> Ok(T data)
{
return new Result<T>(data);
}
public static Result<T> FromError(ResultCode code = ResultCode.Fail, string msg = null, T data = default)
{
return new Result<T>(code, msg, data);
}
}
[HttpGet]
public Result<Store> Get()
{
return Result<Store>.Ok(new Store());
}
这样就稍微好点了
全局处理响应数据
虽然控制器返回值可以统一了，但是异常处理并没有统一，这时候就需要建个中间件/异常过滤器进行处理异常
app.UseMiddleware<GlobalExceptionHandlerMiddleware>();
public class GlobalExceptionHandlerMiddleware
{
private readonly RequestDelegate _next;
public GlobalExceptionHandlerMiddleware(RequestDelegate next)
{
_next = next;
}
public async Task Invoke(HttpContext context)
{
try
{
await _next(context);
}
catch (System.Exception ex)
{
context.Response.StatusCode = 500;
context.Response.ContentType = "text/json;charset=utf-8;";
if (ex is ResultException == false)
{
var logger = context.RequestServices.GetRequiredService<ILoggerFactory>().CreateLogger<GlobalExceptionHandlerMiddleware>();
logger.LogError(1, ex, ex.Message);
}
var json = Result<object>.FromCode(ResultCode.Fail, ex.Message);
var error = JsonSerializer.Serialize(json);
await context.Response.WriteAsync(error);
}
}
}
有些异常是不需要记录的，这时候可以自定义ResultException进行判断
public class ResultException : Exception
{
public ResultException(string message) : base(message)
{
}
public ResultException(string message, Exception e) : base(message, e)
{
}
}
if (ex is ResultException == false)
{
var logger = context.RequestServices.GetRequiredService<ILoggerFactory>().CreateLogger<GlobalExceptionHandlerMiddleware>();
logger.LogError(1, ex, ex.Message);
}
参数校验处理
一个接口一般对参数（请求数据）都会进行安全校验，按照之前的格式返回验证异常。
public class ModelActionFilter : ActionFilterAttribute, IActionFilter
{
public override void OnActionExecuting(ActionExecutingContext context)
{
if (!context.ModelState.IsValid)
{
var errorResults = new List<ErrorResultDto>();
foreach (var item in context.ModelState)
{
var result = new ErrorResultDto
{
Field = item.Key,
Msg = "",
};
foreach (var error in item.Value.Errors)
{
if (!string.IsNullOrEmpty(result.Msg))
{
result.Msg += '|';
}
result.Msg += error.ErrorMessage;
}
errorResults.Add(result);
}
context.Result = new JsonResult(Result<List<ErrorResultDto>>.FromCode(ResultCode.InvalidData, data: errorResults));
}
}
}
public class ErrorResultDto
{
/// <summary>
/// 参数领域
/// </summary>
public string Field { get; set; }
/// <summary>
/// 错误信息
/// </summary>
public string Msg { get; set; }
}
Startup.cs
services.AddControllers(options =>
{
options.Filters.Add(new ModelActionFilter());
options.MaxModelValidationErrors = 50;
options.ModelBindingMessageProvider.SetValueMustNotBeNullAccessor(
_ => "该字段不可为空。");
})
.ConfigureApiBehaviorOptions(options =>
{
options.SuppressModelStateInvalidFilter = true;
})