(400) Bad Request when trying to post simple value to an API

Question

I have this LoansController for a web api

[Route(\"api/[controller]\")]
[ApiController]
public class LoansController : ControllerBase
{
    // G         


        

Answer 1

First, try using ConvertTo-Json in the powershell command:

$postParams = @{ "value": "123"} | ConvertTo-Json
Invoke-WebRequest http://localhost:1113/api/loans -Body $postParams -Method Post -ContentType "application/json"

If it still doesn't work I suggest creating a model (data transfer object) and using model binding to bind your string value. Edit the controller Post method as below:

public class MyModelDto {
    public string Value { get; set; }
}

// POST api/loans
[HttpPost]
public void Post([FromBody] MyModelDto model)
{
    string value = model.Value;
}