MVC模型要求为true

有没有一种方法可以通过数据注释将布尔属性设置为true？

public class MyAwesomeObj{
    public bool ThisMustBeTrue{get;set;}
}

您可以创建自己的验证器：

public class IsTrueAttribute : ValidationAttribute
{
    #region Overrides of ValidationAttribute

    /// <summary>
    /// Determines whether the specified value of the object is valid. 
    /// </summary>
    /// <returns>
    /// true if the specified value is valid; otherwise, false. 
    /// </returns>
    /// <param name="value">The value of the specified validation object on which the <see cref="T:System.ComponentModel.DataAnnotations.ValidationAttribute"/> is declared.
    ///                 </param>
    public override bool IsValid(object value)
    {
        if (value == null) return false;
        if (value.GetType() != typeof(bool)) throw new InvalidOperationException("can only be used on boolean properties.");

        return (bool) value;
    }

    #endregion
}

我将为服务器端和客户端都创建一个验证器。使用MVC和不打扰的表单验证，只需执行以下操作即可实现：

首先，在您的项目中创建一个类，以执行服务器端验证，如下所示：

public class EnforceTrueAttribute : ValidationAttribute, IClientValidatable
{
    public override bool IsValid(object value)
    {
        if (value == null) return false;
        if (value.GetType() != typeof(bool)) throw new InvalidOperationException("can only be used on boolean properties.");
        return (bool)value == true;
    }

    public override string FormatErrorMessage(string name)
    {
        return "The " + name + " field must be checked in order to continue.";
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        yield return new ModelClientValidationRule
        {
            ErrorMessage = String.IsNullOrEmpty(ErrorMessage) ? FormatErrorMessage(metadata.DisplayName) : ErrorMessage,
            ValidationType = "enforcetrue"
        };
    }
}

然后，在模型中注释适当的属性：

[EnforceTrue(ErrorMessage=@"Error Message")]
public bool ThisMustBeTrue{ get; set; }

最后，通过将以下脚本添加到视图中来启用客户端验证：

<script type="text/javascript">
    jQuery.validator.addMethod("enforcetrue", function (value, element, param) {
        return element.checked;
    });
    jQuery.validator.unobtrusive.adapters.addBool("enforcetrue");
</script>

注意：我们已经创建了一种方法GetClientValidationRules，可以将注释从模型推入视图。

如果使用资源文件来提供国际化错误消息，请删除该FormatErrorMessage调用（或仅调用基数）并按如下所示调整GetClientValidationRules方法：

public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
    string errorMessage = String.Empty;
    if(String.IsNullOrWhiteSpace(ErrorMessage))
    {
        // Check if they supplied an error message resource
        if(ErrorMessageResourceType != null && !String.IsNullOrWhiteSpace(ErrorMessageResourceName))
        {
            var resMan = new ResourceManager(ErrorMessageResourceType.FullName, ErrorMessageResourceType.Assembly);
            errorMessage = resMan.GetString(ErrorMessageResourceName);
        }
    }
    else
    {
        errorMessage = ErrorMessage;
    }

    yield return new ModelClientValidationRule
    {
        ErrorMessage = errorMessage,
        ValidationType = "enforcetrue"
    };
}

我知道这是一篇较旧的文章，但想分享一种简单的服务器端方法来做到这一点。您创建一个设置为true的公共属性，然后将布尔值与该属性进行比较。如果您的布尔值未选中（默认为false），则该表单将无法通过验证。

public bool isTrue
{ get { return true; } }

[Required]
[Display(Name = "I agree to the terms and conditions")]
[Compare("isTrue", ErrorMessage = "Please agree to Terms and Conditions")]
public bool AgreeTerms { get; set; }

剃刀代码

@Html.CheckBoxFor(m => Model.AgreeTerms, new { id = "AgreeTerms", @checked = "checked" })
<label asp-for="AgreeTerms" class="control-label"></label>
<a target="_blank" href="/Terms">Read</a>
<br />
@Html.ValidationMessageFor(model => model.AgreeTerms, "", new { @class = "text-danger" })
@Html.HiddenFor(x => Model.isTrue)

我尝试了几种解决方案，但没有一种对我完全有效，无法同时获得客户端和服务器端验证。因此，我在MVC 5应用程序中所做的就是使其正常工作：

在您的ViewModel中（用于服务器端验证）：

public bool IsTrue => true;

[Required]
[Display(Name = "I agree to the terms and conditions")]
[Compare(nameof(IsTrue), ErrorMessage = "Please agree to Terms and Conditions")]
public bool HasAcceptedTermsAndConditions { get; set; }

在您的Razor页面中（用于客户端验证）：

<div class="form-group">
   @Html.CheckBoxFor(m => m.HasAcceptedTermsAndConditions)
   @Html.LabelFor(m => m.HasAcceptedTermsAndConditions)
   @Html.ValidationMessageFor(m => m.HasAcceptedTermsAndConditions)

   @Html.Hidden(nameof(Model.IsTrue), "true")
</div>

我只想将人们引向以下小提琴：https : //dotnetfiddle.net/JbPh0X

用户添加 [Range(typeof(bool), "true", "true", ErrorMessage = "You gotta tick the box!")]到其boolean属性中，该属性使服务器端验证起作用。

为了也可以进行客户端验证，他们添加了以下脚本：

// extend jquery range validator to work for required checkboxes
var defaultRangeValidator = $.validator.methods.range;
$.validator.methods.range = function(value, element, param) {
    if(element.type === 'checkbox') {
        // if it's a checkbox return true if it is checked
        return element.checked;
    } else {
        // otherwise run the default validation function
        return defaultRangeValidator.call(this, value, element, param);
    }
}

只需检查其字符串表示形式是否等于True：

[RegularExpression("True")]
public bool TermsAndConditions { get; set; }

您可以创建自己的属性，也可以使用CustomValidationAttribute。

这是使用CustomValidationAttribute的方式：

[CustomValidation(typeof(BoolValidation), "ValidateBool")]

其中BoolValidation定义为：

public class BoolValidation
{
  public static ValidationResult ValidateBool(bool boolToBeTrue)
  {
    if (boolToBeTrue)
    {
      return ValidationResult.Success;
    }
    else
    {
      return new ValidationResult(
          "Bool must be true.");
    }
  }

[Required]属性代表要求任何值-可以为true或false。您必须为此使用另一个验证。

跟随ta.speot.is的帖子以及Jerad Rose的评论：

给定的帖子将不会在客户端进行不打扰的验证。这在两个阵营（客户端和服务器）中都应该起作用：

[RegularExpression("(True|true)")]
public bool TermsAndConditions { get; set; }

.NET Core MVC-带有数据注释的必需复选框

public class MyModel
{
    [Display(Name = "Confirmation")]
    [Range(typeof(bool), "true", "true", ErrorMessage = "Please check the Confirmation checkbox.")]
    public bool IsConfirmed { get; set; }   
}

<div class="custom-control custom-checkbox col-10">
    <input type="checkbox" asp-for="IsConfirmed" class="custom-control-input" />
    <label class="custom-control-label" for="IsConfirmed">
        "By clicking 'submit', I confirm."
    </label>
    <span asp-validation-for="IsConfirmed" class="text-danger"></span>
</div>

<script src="~/lib/jquery-validation/dist/jquery.validate.js"></script>
<script src="~/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.js"></script>

<script type="text/javascript">
    $(document).ready(function () {
        // extend range validator method to treat checkboxes differently
        var defaultRangeValidator = $.validator.methods.range;
        $.validator.methods.range = function (value, element, param) {
            if (element.type === 'checkbox') {
                // if it's a checkbox return true if it is checked
                return element.checked;
            } else {
                // otherwise run the default validation function
                return defaultRangeValidator.call(this, value, element, param);
            }
        }
    });
</script>

我不知道通过DataAnnotations的方法，但是这很容易在您的控制器中完成。

public ActionResult Add(Domain.Something model)
{

    if (!model.MyCheckBox)
        ModelState.AddModelError("MyCheckBox", "You forgot to click accept");

    if (ModelState.IsValid) {
        //'# do your stuff
    }

}

唯一的其他选择是为服务器端构建自定义验证器，为客户端构建远程验证器（远程验证仅在MVC3 +中可用）

您是否在web.config中设置了适当的项目？

这可能导致验证无效。

您还可以尝试创建自定义验证属性（因为[Required]仅关心该属性是否存在，并且您关心该值）：

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, AllowMultiple = false)]
sealed public class RequiredTrueAttribute : ValidationAttribute
{
    // Internal field to hold the mask value.
    readonly bool accepted;

    public bool Accepted
    {
        get { return accepted; }
    }

    public RequiredTrueAttribute(bool accepted)
    {
        this.accepted = accepted;
    }

    public override bool IsValid(object value)
    {
        bool isAccepted = (bool)value;
        return (isAccepted == true);
    }

    public override string FormatErrorMessage(string name)
    {
        return String.Format(CultureInfo.CurrentCulture,
          ErrorMessageString, name, this.Accepted);
    }
}

然后，用法：

[RequiredTrue(ErrorMessage="{0} requires acceptance to continue.")]
public bool Agreement {get; set;}

从这里。

这对我有用。什么也没做。Mvc 5：

模型

public string True
{
  get
  {
    return "true";
  }
}

[Required]
[Compare("True", ErrorMessage = "Please agree to the Acknowlegement")]
public bool Acknowlegement { get; set; }

视图

  @Html.HiddenFor(m => m.True)
  @Html.EditorFor(model => model.Acknowlegement, new { htmlAttributes = Model.Attributes })
  @Html.ValidationMessageFor(model => model.Acknowlegement, "", new { @class = "text-danger" })

对于ASP.NET Core MVC，这是基于dazbradbury解决方案的客户端和服务器验证

public class EnforceTrueAttribute : ValidationAttribute, IClientModelValidator
{
    public override bool IsValid(object value)
    {
        if (value == null) return false;
        if (value.GetType() != typeof(bool)) throw new InvalidOperationException("can only be used on boolean properties.");
        return (bool)value;
    }

    public void AddValidation(ClientModelValidationContext context)
    {
        MergeAttribute(context.Attributes, "data-val", "true");
        var errorMessage = ErrorMessage ?? 
            $"The value for field {context.ModelMetadata.GetDisplayName()} must be true.";
        MergeAttribute(context.Attributes, "data-val-enforcetrue", errorMessage);
    }

    private void MergeAttribute(IDictionary<string, string> attributes,
        string key,
        string value)
    {
        if (attributes.ContainsKey(key))
        {
            return;
        }
        attributes.Add(key, value);
    }
}

然后在客户端上：

$.validator.addMethod("enforcetrue", function (value, element, param) {
    return element.checked;
});

$.validator.unobtrusive.adapters.addBool("enforcetrue");

然后用法是：

[EnforceTrue(ErrorMessage = "Please tick the checkbox")]
public bool IsAccepted { get; set; }

我尝试使用fields.cage的答案，但它对我而言并不奏效，但更简单的方法做了，而且我不确定为什么（不同的Razor版本？），但是我要做的就是：

[Required]
[Range(typeof(bool), "true", "true", ErrorMessage = "Agreement required.")]
[Display(Name = "By clicking here, I agree that my firstborn child will etc etc...")]
public bool Agreement1Checked { get; set; }

在.cshtml文件中：

@Html.CheckBoxFor(m => m.Agreement1Checked)
@Html.LabelFor(m => m.Agreement1Checked)
@Html.ValidationMessageFor(m => m.Agreement1Checked)

我认为处理此问题的最佳方法是，如果该框为true，则只需检查控制器，否则只需向模型添加错误并使其重新显示视图即可。

如前所述，所有[Required]都要做的是确保有一个值，并且在您的情况下，如果未选中，您仍然会得到false。

在此处查看万无一失的验证。您可以通过Nuget下载/安装它。

这是一个很棒的小型图书馆。

/// <summary> 
///  Summary : -CheckBox for or input type check required validation is not working the root cause and solution as follows
///
///  Problem :
///  The key to this problem lies in interpretation of jQuery validation 'required' rule. I digged a little and find a specific code inside a jquery.validate.unobtrusive.js file:
///  adapters.add("required", function (options) {
///  if (options.element.tagName.toUpperCase() !== "INPUT" || options.element.type.toUpperCase() !== "CHECKBOX") {
///    setValidationValues(options, "required", true);
///    }
///   });
///   
///  Fix: (Jquery script fix at page level added in to check box required area)
///  jQuery.validator.unobtrusive.adapters.add("brequired", function (options) {
///   if (options.element.tagName.toUpperCase() == "INPUT" && options.element.type.toUpperCase() == "CHECKBOX") {
///              options.rules["required"] = true;
///   if (options.message) {
///                   options.messages["required"] = options.message;
///                       }
///  Fix : (C# Code for MVC validation)
///  You can see it inherits from common RequiredAttribute. Moreover it implements IClientValidateable. This is to make assure that rule will be propagated to client side (jQuery validation) as well.
///  
///  Annotation example :
///   [BooleanRequired]
///   public bool iAgree { get; set' }
/// </summary>


public class BooleanRequired : RequiredAttribute, IClientValidatable
{

    public BooleanRequired()
    {
    }

    public override bool IsValid(object value)
    {
        return value != null && (bool)value == true;
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        return new ModelClientValidationRule[] { new ModelClientValidationRule() { ValidationType = "brequired", ErrorMessage = this.ErrorMessage } };
    }
}