Question

我正在使用带有DataAnnotations的ASP.NET MVC。我创建了以下自定义ValidationAttribute，它可以正常工作。

public class StringRangeAttribute : ValidationAttribute
{
    public int MinLength { get; set; }
    public int MaxLength { get; set; }

    public StringRangeAttribute(int minLength, int maxLength)
    {   
        this.MinLength = (minLength < 0) ? 0 : minLength;
        this.MaxLength = (maxLength < 0) ? 0 : maxLength;
    }

    public override bool IsValid(object value)
    {            
        //null or empty is <em>not</em> invalid
        string str = (string)value;
        if (string.IsNullOrEmpty(str))
            return true;

        return (str.Length >= this.MinLength && str.Length <= this.MaxLength);
    }
}

但是，出现的错误消息是标准的“字段*无效”。我想将其更改为：“[DisplayName]必须介于[minlength]和[maxlength]之间”，但我无法弄清楚如何从此类中获取DisplayName甚至字段的名称。

有人知道吗？

Answer 1

略微修改了StringLengthAttribute：

public class StringRangeAttribute : ValidationAttribute
{
    // Methods
    public StringRangeAttribute(int minimumLength, int maximumLength)
        : base(() => "The {0} must be between {1} and {2} chars long.")
    {
        MaximumLength = maximumLength;
        MinimumLength = minimumLength;
    }

    public override string FormatErrorMessage(string name)
    {
        return string.Format(CultureInfo.CurrentCulture, ErrorMessageString, new object[] { name, MinimumLength ,MaximumLength });
    }

    public override bool IsValid(object value)
    {
        if (value != null)
        {
            return (((string)value).Length <= MaximumLength) && (((string)value).Length >= MinimumLength);
        }
        return true;
    }

    public int MaximumLength { get; set; }
    public int MinimumLength { get; set; }
}

ASP.NET MVC：添加将DisplayName合并到自定义ValidationAttribute的自定义ErrorMessage

1 个答案: