asp.net-mvc-4 - 将自定义参数传递给ValidationAttribute

Question

我建立了一个自定义的ValidationAttribute，以便可以验证系统中的唯一电子邮件地址。但是，我想以某种方式传递自定义参数，以向验证添加更多逻辑。

public class UniqueEmailAttribute : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        //I need the original value here so I won't validate if it hasn't changed.
        return value != null && Validation.IsEmailUnique(value.ToString());
    }
}

Answer 1

像这样？

public class StringLengthValidatorNullable : ValidationAttribute
{
    public int MinStringLength { get; set; }
    public int MaxStringLength { get; set; }

    public override bool IsValid(object value)
    {
        if (value == null)
        {
            return false;
        }
        var length = value.ToString().Length;

        if (length < MinStringLength || length >= MaxStringLength)
        {
            return false;
        }
        return true;
    }
}

用：

[StringLengthValidatorNullable(MinStringLength = 1, MaxStringLength = 16)]
public string Name {get; set;}