string IDataErrorInfo.this[string propertyName]
{
get
{
string error = string.Empty;
var dpDescriptor = DependencyPropertyDescriptor.FromName(propertyName, this.GetType(), this.GetType());
if (dpDescriptor != null)
{
var results = new List <ValidationResult>(1);
var result = Validator.TryValidateProperty(
value: this.GetValue(dpDescriptor.DependencyProperty),
validationContext: new ValidationContext(this)
{
MemberName = propertyName
},
validationResults: results);
if (!result)
{
var validationResult = results.First();
error = validationResult.ErrorMessage;
if (ValidationErrors.Contains(propertyName))
{
ValidationErrors[propertyName] = error;
}
else
{
ValidationErrors.Add(propertyName, error);
}
}
else
{
if (ValidationErrors.Contains(propertyName))
{
ValidationErrors.Remove(propertyName);
}
}
}
IsValid = ValidationErrors.Count > 0 ? false : true;
return(error);
}
}