C＃无法使用自定义验证属性来验证属性

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我有一个验证类：

public sealed class ValidationSet : ValidationAttribute { private List<string> _set = new List<string>(); public ValidationSet(params string[] setOfValues) { _set = setOfValues.ToList(); } protected override ValidationResult IsValid(object value, ValidationContext validationContext) { if (!(_set.Select(s => s.ToLower()).Contains(value.ToString().ToLower()))) { throw new Exception("not in the set"); } return ValidationResult.Success; } }

这是我的用法：

public class Car { [ValidationSet("honda", "gm")] public string CarMake{ get; set; } }

当我通过以下方式实例化Car类时：

When I instantiate the Car class by:

... Car c = new Car(); c.CarMake = "ford"; ...

什么都不会发生，如果我打印c.CarMake，它会显示福特-验证没有发生。

Nothing will happen and if I print c.CarMake, it shows ford - the validation didn't happened.

我只是想知道我在这里想念什么。

I am just wondering what do I miss here.

谢谢！

推荐答案

仅实例化该类并分配该字段不会调用IsValid，您需要在检查Car的框架中使用该类，看看它是否具有ValidationAttribute

Just instantiating the class and assigning the field is not going to call IsValid, you need to use the class in a framework that examines Car, sees that it has ValidationAttribute on CarMake and will call IsValid.

在此示例中，asp：DynamicValidator正在执行此工作：

In this example asp:DynamicValidator is doing the work:

如何：自定义数据字段验证