WPF的CompareAttribute？

Question

Does anyone know of a CompareAttribute data annotation for WPF, or a way of achieving the same result in WPF?

For those that don't immediately know, CompareAttribute is a property data annotation for validating in WPF, it takes a string for a second property and returns true if the decorated property and the passed property match.

Basically I need to validate a password change form, to ensure the "retyped password" matches the new password, and do this with data annotations so that i can use the xaml validation template.

Answer 1

您可以通过创建此处描述的自己的CustomValidationAttribute来创建自己的自定义验证逻辑。

Answer 2

Try Custom Validator like this

    public class EqualsValidationAttribute : ValidationAttribute
{
    string propertyToCompare;
    public EqualsValidationAttribute(string propertyToCompare)
    {
        this.propertyToCompare = propertyToCompare;
    }

    public EqualsValidationAttribute(string propertyToCompare,string errorMessage):this(propertyToCompare)
    {
        this.ErrorMessage = propertyToCompare;
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        var propInfo=validationContext.ObjectInstance.GetType().GetProperty(propertyToCompare);
        if (propInfo != null)
        {
            var propValue=propInfo.GetValue(validationContext.ObjectInstance);
            if(value!=null && propValue!=null && !string.IsNullOrEmpty(value.ToString()) && !string.IsNullOrEmpty(propValue.ToString()) //if either one is empty dont Validate
                && (value.ToString() != propValue.ToString()))
                return new ValidationResult(ErrorMessage);
        } 
        else
            throw new NullReferenceException("propertyToCompare must be the name of property to compare");

        return ValidationResult.Success;
    } 
}

and use it in Entity like this

    [Required(ErrorMessage="Password Required")]
    public string Password {
        get { return password; }
        set { password = value; RaisePropertyChanged("Password"); }
    }

    [EqualsValidationAttribute("Password", ErrorMessage = "Confirm password must be same as password")]
    public string ConfirmPassword {
        get { return confirmedpassword; }
        set { confirmedpassword = value; RaisePropertyChanged("ConfirmPassword"); }
    }
}