数组必须包含1元

本文介绍了数组必须包含1元的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有以下类：

public class CreateJob { [Required] public int JobTypeId { get; set; } public string RequestedBy { get; set; } public JobTask[] TaskDescriptions { get; set; } }

我想有上述 TaskDescriptions 数据标注，这样的阵列必须至少包含一个元素？就像 [必需] 。这可能吗？

I'd like to have a data annotation above TaskDescriptions so that the array must contain at least one element? Much like [Required]. Is this possible?

推荐答案

我见过之前用于此自定义验证属​​性，如：

I've seen a custom validation attribute used for this before, like this:

（我已经给定的样本与列表，但可以适用于数组或者你可以使用列表）

(I've given sample with a list but could be adapted for array or you could use list)

public class MustHaveOneElementAttribute : ValidationAttribute { public override bool IsValid(object value) { var list = value as IList; if (list != null) { return list.Count > 0; } return false; } } [MustHaveOneElementAttribute (ErrorMessage = "At least a task is required")] public List<Person> TaskDescriptions { get; private set; }