验证之 ValidationRule 简单Demo

验证用户是否年满18+

 public class AgeRule : ValidationRule
    {
        private Double limitAge = 18;
  
        public Double LimitAge
        {
            get { return limitAge; }
            set { limitAge = value; }
        }

        public override ValidationResult Validate(object value, CultureInfo cultureInfo)
        {
            Double age = (Double)value ;
            if (limitAge < age  )
            {
                return new ValidationResult(true, null);
            }
            else {
                return new ValidationResult(false,"年龄范围错误");
            }
        }
    }

　

页面使用：

  <StackPanel>
        <Slider x:Name="age" Minimum="0" Maximum="100" />
        <Label >
            <Label.Content>
                <Binding  ElementName="age" Path="Value" Mode="OneWay" UpdateSourceTrigger="PropertyChanged">
                    <Binding.ValidationRules>
                        <local:AgeRule  ValidatesOnTargetUpdated="True"/>
                    </Binding.ValidationRules>
                </Binding>
            </Label.Content>
        </Label>
</StackPanel>

效果一：

 

 效果二：