ASP.NET Core MVC controller receives null for input parameter from ajax call

Question

I have an ajax call:

...
$("#testBtn").click(function (e) {
    e.preventDefault();
    $.ajax({
        url: "/profile/GuestList",
        data: {"keytype": "1"},
        method: "POST",
        contentType: "application/json",
        success: function (data) {
           ...
        }
    });
});
...

and my controller method:

[HttpPost]
public async Task<IActionResult> GuestList([FromBody]string keytype)
{
    try
    {
        return Ok();
    }
    catch (Exception ex)
    {

    }
}

So, inititally I wanted to send an enum type, but that didnt work, so I wanted to send an int with value 1 and I kept getting only 0, then I added [FromBody] and it was the same, at last I switched to string just in case, and now Im getting a null value.

Where I went wrong in all this variations?

Serge · Accepted Answer · 2021-03-10 12:41:24Z

3

Create class

public class KeyTypeViewModel
{
    public string Keytype { get; set; }
}

Fix action by removing [FromBody]

[HttpPost]
public async Task<IActionResult> GuestList(KeyTypeViewModel viewModel)

And fix ajax by removing contentType: "application/json" :

$.ajax({
        url: "/profile/GuestList",
        data: {keytype: "1"},
        method: "POST",
       success: function (data) {
           ...
        }

answered Mar 10, 2021 at 12:41

Serge

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Comments

yo chauhan · Accepted Answer · 2021-03-10 12:37:30Z

2

You need to create a Dto that has property keytype.

public class SomeDto
{
    public string Keytype { get; set; }
}

[HttpPost]
public async Task<IActionResult> GuestList([FromBody]SomeDto dto)

answered Mar 10, 2021 at 12:37

yo chauhan

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2 Comments

lonelydev101 Over a year ago

but theres no really need to wrap one property into whole class?

yo chauhan Over a year ago

if you see in Post ajax call you are sending an object {"keytype": "1"}.

Balaji Kanagaraju · Accepted Answer · 2021-03-10 12:56:34Z

0

You have to update your data in your Ajax call to a string as you are using string as input parameter in your POST method.

...
$("#testBtn").click(function (e) {
    e.preventDefault();
    $.ajax({
        url: "/profile/GuestList",
        data:  "1",
        method: "POST",
        contentType: "application/json",
        success: function (data) {
           ...
        }
    });
});
...

answered Mar 10, 2021 at 12:56

Balaji Kanagaraju

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Comments

Ask · Accepted Answer · 2021-03-10 12:59:23Z

0

You must stringify your data.

Try the following:

$.ajax({
   url: "/profile/GuestList",
   data: JSON.stringify({"keytype": "1"}),
   method: "POST",
   contentType: "application/json",
   success: function (data) {
           ...
        }
    });

answered Mar 10, 2021 at 12:59

Ask

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