WPF TextBox 正则验证 大于等于0 小于等于1 的两位小数

正则：^(0\.\d+|[1-9][0-9]|1)$

textbox绑定正则验证

<textbox x:name="txb"   maxlength="6" margin="1 0 0 0"  width="40" >
    <textbox.text>
        <binding path="opacity" validatesonexceptions="true" validatesondataerrors="true" stringformat="f2"            
          mode="twoway" updatesourcetrigger="propertychanged"                              >
            <binding.validationrules>
                <shared1:inventoryvalidationrule  inventorypattern="^(0\.\d+|[1-9][0-9]|1)$"/>
            </binding.validationrules>
       </binding>
    </textbox.text>
</textbox>

用到的inventoryvalidationrule类：

 public class inventoryvalidationrule : validationrule
    {
        #region properties

        public string inventorypattern { get; set; }

        #endregion properties

        #region methods

        public override validationresult validate(
                  object value, cultureinfo cultureinfo)
        {
            if (inventorypattern == null)
                return validationresult.validresult;

            if (!(value is string))
                return new validationresult(false,
               "inventory should be a comma separated list of model numbers as a string");

            string[] pieces = value.tostring().split(',');
            regex m_regex = new regex(inventorypattern);

            foreach (string item in pieces)
            {
                match match = m_regex.match(item);
                if (match == null || match == match.empty)
                    return new validationresult(
                      false, "invalid input format");
            }

            return validationresult.validresult;
        }

        #endregion methods
    }