ASP.NET Core 2, jQuery POST data null

Question

I use jQuery and send data with the POST method. But in the server method the values are not coming. What could be the error?

client

Answer 1

Use [FromBody] before the param. It's check and Get the Property value in body otherwise it's check the Url Querystring.

Example:

[HttpPost]
public JObject AddTag([FromBody] int parentid,[FromBody]string tagname)
{

}

[HttpPost]
public JObject AddTag([FromBody] {ModelName} parent)
{

}

Answer 2

Try extracting your params into a separate DTO class and do it like that:

public class ParentDTO 
{
 public int parentId{get; set;}
 public string tagName{ get; set;}
}

[HttpPost]
public JObject AddTag([FromBody] ParentDTO parent)
{

}

Answer 3

Change your ajax to this

$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "./AddTag?parentId="+42+"&tagName="+'isTagName',
dataType: "json",
success: function (response) {
    // ...
}

});