/// <summary>
/// 确定对象的指定值是否有效。
/// </summary>
/// <param name="value"></param>
/// <param name="validationContext"></param>
/// <returns></returns>
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
if (value == null)
{
return(base.IsValid(null, validationContext));
}
var encodedValue = EncoderHelper.HtmlEncode(value.ToString(), false);
if (EncodedStringAndValueAreDifferent(value, encodedValue))
{
SetupAllowedStringsDictionary();
foreach (var allowedString in allowedStringsDictionary)
{
encodedValue = encodedValue.Replace(allowedString.Value, allowedString.Key);
}
if (EncodedStringAndValueAreDifferent(value, encodedValue))
{
return(new ValidationResult(SetErrorMessage(validationContext)));
}
}
if (!string.IsNullOrWhiteSpace(disallowedStrings) &&
disallowedStrings.Split(',').Select(x => x.Trim()).Any(x => value.ToString().Contains(x)))
{
return(new ValidationResult(SetErrorMessage(validationContext)));
}
return(base.IsValid(value, validationContext));
}
private void SetupAllowedStringsDictionary()
{
if (string.IsNullOrWhiteSpace(allowedStrings))
{
return;
}
foreach (var allowedString in allowedStrings.Split(',').Select(x => x.Trim())
.Where(allowedString => !allowedStringsDictionary.ContainsKey(allowedString)))
{
allowedStringsDictionary.Add(allowedString,
EncoderHelper.HtmlEncode(allowedString, false));
}
}