Fluent Validation 将 CustomAsync 更改为 MustAsync

有人可以帮我解决这个问题吗？我正在努力改变CustomAsync 到 MustAsync，但我无法让事情发挥作用。下面是我的自定义方法

RuleFor(o => o).MustAsync(o => {
            return  CheckIdNumberAlreadyExist(o)
          });

      private static async Task<ValidationFailure> CheckIdNumberAlreadyExist(SaveProxyCommand command)
      {
          if (command.Id > 0)
              return null;

          using (IDbConnection connection = new SqlConnection(ConnectionSettings.LicensingConnectionString))
          {
              var param = new DynamicParameters();
              param.Add("@idnumber", command.IdNumber);

              var vehicle = await connection.QueryFirstOrDefaultAsync<dynamic>("new_checkDuplicateProxyIdNumber", param, commandType: CommandType.StoredProcedure);

              return vehicle != null
                  ? new ValidationFailure("IdNumber", "Id Number Already Exist")
                  : null;
          }
       }

为了使其与最新版本的 FluentValidation 一起使用，我必须使用如下代码。

RuleFor(ws => ws).MustAsync((x, cancellation) => UserHasAccess(x)).WithMessage("User doesn't have access to perform this action");

请注意这里的 lambda 表达式MustAsync((x, cancellation) => UserHasAccess(x))，如果没有这个我总是会收到错误cannot convert from 'method group' to 'Func<Worksheet, CancellationToken, Task<bool>>

下面是我的习惯UserHasAccess功能。

private async Task <bool> UserHasAccess(Worksheet worksheet) {
    var permissionObject = await _dataProviderService.GetItemAsync(worksheet.FileItemId);
    if (permissionObject is null) return false;
    if (EditAccess(permissionObject.Permission)) return true;
    return false;
}