$.post always getting null values into server

Question

Ok, this might be simple, I'm having a simple $.post call to server sending string array as parameters..

 $.get('/home/ReadCalPacTagValue', data, function (data) {
            data = $.parseJSON(data);
            if (data.length != 0) {
                var ReadFromDb = data[0]["PushToDb"].replace('PushToDb','ReadFromDb');
                var DBAckno = ReadFromDb.replace('ReadFromDb', 'DataAck');
                var FIdTag = ReadFromDb.replace('ReadFromDb', 'FluidTypeId');
                var UserIdTag = ReadFromDb.replace('ReadFromDb', 'UserId');
                var UniqueIdTag = ReadFromDb.replace('ReadFromDb', 'UniqueRecordId');
                var dbconnTag = ReadFromDb.replace('ReadFromDb', 'DatabaseConnectionString');
                updateTags = [dbconnTag,FIdTag,ReadFromDb, UserIdTag,UniqueIdTag];
                actionvalue = ["", fluidtypeid, '1', userid, uniqueID];
                var data_Tags = { updateTags: updateTags, actionvalue: actionvalue }
                $.post('/home/WriteCalPacTagValue', data_Tags, function (response) {
                    //var Path = "Config/16_CalPac/" + FluidType + "/" + metername + "/" + FileName
                    //$.cookie('FileName', FileName, { expires: 7, path: '/' });
                    //$.cookie('FilePath', Path, { expires: 7, path: '/' });
                    //$.cookie('ModuleName', "CalPac", { expires: 7, path: '/' });
                    //window.open('../home/CalPac', '_blank');
                });
            } else {
                    swal("Error !", "Data operation tag not binded for this product", "warning");
            }
        })

my problem is, every time it makes $.post call, server is getting null values int prarameters..

 public void WriteCalPacTagValue(string[] updateTags, string[] actionValue)
        {
            string[] writetags = { };
            DanpacUIRepository objNewTag = new DanpacUIRepository();

            if (updateTags.Count() > 0)
            {
                actionValue[0] = ConfigurationManager.AppSettings["DBString"].ToString();
                for (int i = 0; i < updateTags.Count(); i++)
                {

                    writetags = updateTags[i].Replace("&lt;", "").Replace("&gt;", ">").Split('>');
                    objNewTag.WriteTag(writetags, actionValue[i]);
                }

            }
        }

I'm not getting what I've done wrong here.. whereas same function is working from another JS file with some difference string into array updateTags.

any help?

Your sending arrays of data so you need to use the `$.ajax()` method so that you can set `contentType: 'application/json',` and use stringify the data - `data: JSON.stringify(data_Tags),` . Alternatively you must send individual collection items - `{ updateTags[0]: dbconnTag, updateTags[1]:'FIdTag, .... }` — , Jun 16 '17 at 13:54
Try with `ajax` and `traditional: true` - https://stackoverflow.com/questions/11868051/jquery-post-with-serialize-and-array-of-data — Dan Dumitru, Jun 16 '17 at 13:58
Thanks This solved problem when I explicitly set ajaxsetting traditional:true.. — Abhinav, Jun 16 '17 at 14:15

Hossein Narimani Rad · Answer 1 · 2017-06-16T14:33:16.560

Having

public class DataTags
{
    public string[] UpdateTags { get; set; }
    public string[] ActionValue { get; set; }
}

At the server: Change the method to this

[HttpPost()]
public void WriteCalPacTagValue([FromBody]DataTags data_Tags)
{

}

At the client: call it

$.ajax({
    type: 'POST',
    url: '/home/WriteCalPacTagValue',
    data: data_Tags,
    success: function (response) { 
    //your code
    }
});

Also you can send the whole data as json string using data: JSON.stringify(data_Tags), in javascript code the change the WriteCalPacTagValue to accept a single string at the parameter and deserialize it in C# code at the server side.

EDIT if you cannot change the server side code, you may follow this as stated in the comments.

thanks for your solution Hossein, but I can't make changes at C# side. — Abhinav, Jun 16 '17 at 14:29

$.post always getting null values into server

1 Answers1