Question

在代码重复的许多操作中，基于模型状态验证属性时，我必须抛出自定义异常。

如何重构？

当前代码示例

[HttpGet("{jobId}/employeeLog")]
public async Task<IActionResult> GetFileLog(Guid jobId,
    [FromQuery] Guid employeeId,
    [SkipAndTopFromQuery] int? skip,
    [SkipAndTopFromQuery] int? top,
    [FromHeader(Name = "X-Correlation-ID")] string correlationId)
{
    var employeeIdToValidate = ModelState["employeeId"];
    var jobIdToValidate = ModelState["jobId"];
    if (employeeIdToValidate == null || employeeIdToValidate != null && employeeIdToValidate.Errors.Any())
        throw new InvalidFileIdException();
    if (jobIdToValidate == null || jobIdToValidate != null && jobIdToValidate.Errors.Any())
        throw new InvalidApplicationIdException();
    if (!ModelState.IsValid)
        return StatusCode((int)HttpStatusCode.BadRequest);

    ....
}

Answer 1

如果您想简化 if 语句，可以使用Null Propagation Operator in C#

public async Task<IActionResult> GetFileLog(Guid jobId,
    [FromQuery] Guid employeeId,
    [SkipAndTopFromQuery] int? skip,
    [SkipAndTopFromQuery] int? top,
    [FromHeader(Name = "X-Correlation-ID")] string correlationId)
{
    var employeeIdToValidate = ModelState["employeeId"];
    var jobIdToValidate = ModelState["jobId"];

    if (employeeIdToValidate?.Errors?.Any() ?? true)
        throw new InvalidFileIdException();

    if (jobIdToValidate?.Errors?.Any() ?? true)
        throw new InvalidApplicationIdException();

    if (!ModelState.IsValid)
        return StatusCode((int)HttpStatusCode.BadRequest);

    ....
}

此外，如果您的ModelState返回相同的对象或具有公共接口的对象，您可以将检查移动到某种方法。

顺便说一句，您可以通过创建某种类（如 validator ）来从您的方法中拆分验证：

class GetFileLogValidatior: ValidatorBase {

    public override void Validate(GetFileLogValidatiorContext context) {

        var employeeIdToValidate = context.EmployeeIdToValidate;
        var jobIdToValidate = context.JobIdToValidate;

        if (employeeIdToValidate?.Errors?.Any() ?? true)
            throw new InvalidFileIdException();

        if (jobIdToValidate?.Errors?.Any() ?? true)
            throw new InvalidApplicationIdException();
    }

}

验证特定操作参数时抛出自定义异常

1 个答案: