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Ramco Ramco

5yAsked May 29, 2021, 11:28 AM613.NET

Hi

I have 2 fields Id , Description . I want when user Lostfocus on field Id it should check without Post Back whether Id field exists or not.

Thanks

1 Reply

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Sachin Singh5y ago
if by Id exists or not, you mean that it must not be empty then
$("#txtId").focusout(function(){
if($(this).val()==""){
$('this').css('border-color', 'red');
}

});
If you mean whether the id field exists in the database or not? then follow below approach
public class IdCheck:ValidationAttribute
{
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var ids= yourContext.Locations.select(x=>x.Id);
Location location= (Location)validationContext.ObjectInstance;
        bool istrue = ids.Any(x => x == location.Id);
        if (istrue)
{
            return new ValidationResult("Id is in use");
}
        return ValidationResult.Success;
}
}
public class Location
{
[Required(ErrorMessage="can not be empty")]
[IdCheck]
    public string Id{ get; set; }
.... other props...
}
Now in the view use
@Html.TextBoxFor(x=>x.Id)
@Html.ValidationMessageFor(x=>x.Id)
Note:- Give the reference of Jquery.Validate and Jquery.Unobtrusive.Validate
Now on focus lost, you will get an appropriate error message.
+1