如何创建自定义验证属性

本文关键字：自定义 验证 属性 创建 何创建 | 更新日期: 2023-09-27 18:04:19

我正在尝试创建一个自定义验证属性。

public class PhoneValidator : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        return new RegularExpressionAttribute(@"^[+0]'d+").IsValid(Convert.ToString(value).Trim());
    }
}

我用这个来使用

[PhoneValidator]
public string PhoneNumber { get; private set; }

我从一个网站上复制的，理论上这应该是可行的。

如何创建自定义验证属性

来自MSDN的示例:

PhoneMaskAttribute cs: 

using System;
using System.Globalization;
using System.ComponentModel.DataAnnotations;

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, AllowMultiple = false)]
sealed public class PhoneMaskAttribute : ValidationAttribute
{
    // Internal field to hold the mask value.
    readonly string _mask;
    public string Mask
    {
        get { return _mask; }
    }
    public PhoneMaskAttribute(string mask)
    {
        _mask = mask;
    }

    public override bool IsValid(object value)
    {
        var phoneNumber = (String)value;
        bool result = true;
        if (this.Mask != null)
        {
            result = MatchesMask(this.Mask, phoneNumber);
        }
        return result;
    }
    // Checks if the entered phone number matches the mask.
    internal bool MatchesMask(string mask, string phoneNumber)
    {
        if (mask.Length != phoneNumber.Trim().Length)
        {
            // Length mismatch.
            return false;
        }
        for (int i = 0; i < mask.Length; i++)
        {
            if (mask[i] == 'd' && char.IsDigit(phoneNumber[i]) == false)
            {
                // Digit expected at this position.
                return false;
            }
            if (mask[i] == '-' && phoneNumber[i] != '-')
            {
                // Spacing character expected at this position.
                return false;
            }
        }
        return true;
    }
    public override string FormatErrorMessage(string name)
    {
        return String.Format(CultureInfo.CurrentCulture,
          ErrorMessageString, name, this.Mask);
    }
}

用法:

CustomerMetadata.cs: 

using System.Web.DynamicData;
using System.ComponentModel.DataAnnotations;
[MetadataType(typeof(CustomerMetadata))]
public partial class Customer
{
}
public class CustomerMetadata
{
    [PhoneMask("999-999-9999",
        ErrorMessage = "{0} value does not match the mask {1}.")]
    public object Phone; 
}

链接:

如何使用自定义属性在数据模型中自定义数据字段验证

1-创建class 

    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
    public class MobileValidationAttribute : ValidationAttribute
    {
        public MobileValidationAttribute(string errorMessage)
        {
            ErrorMessage = errorMessage;
        }
        public override bool IsValid(object value)
        {
            if (value == null) return false;
            return value.ToString().Length == 13;
        }
    }

创建model 

    public class UserModel
    {
        [Display(Name ="Phone Number")]
        [MobileValidation("{0} is invalid")]
        [Required(AllowEmptyStrings =false,ErrorMessage ="{0} is required")]
        public string PhoneNumber { get; set; }
    }

在视图中使用此代码

@model TestAttribute.Models.UserModel
@{
    Layout = null;
}
<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>
    <div> 
        <form method="post" action="/Home/Index">
            @Html.LabelFor(a=>a.PhoneNumber)
            @Html.TextBoxFor(a=>a.PhoneNumber)
            @Html.ValidationMessageFor(a=>a.PhoneNumber)
            <br />
            <br />
            <button type="submit">Add</button>
        </form>
    </div>
</body>
</html>

4-和Controller 

public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View(new UserModel());
        }
        [HttpPost]
        public ActionResult Index(UserModel model)
        {
            if (ModelState.IsValid)
            {
                return Content("Ok");
            }
            return View(model);
        }
    }
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