The input was not valid .Net Core Web API
Question
I am facing a weird issue and almost spent 4 hours with no luck.
I have a simple Web API which I am calling on form submit.
API-
// POST: api/Tool
[HttpPost]
public void Post([FromBody] Object value)
{
_toolService.CreateToolDetail(Convert.ToString(value));
}
HTML-
<!DOCTYPE html>
<html>
<body>
<h2>HTML Forms</h2>
<form name="value" action="https://localhost:44352/api/tool" method="post">
First name:<br>
<input type="text" id="PropertyA" name="PropertyA" value="Some value A">
<br>
Last name:<br>
<input type="text" id="PropertyB" name="PropertyB" value="Some value B">
<br><br>
<!--<input type="file" id="Files" name="Files" multiple="multiple"/>-->
<br><br>
<input type="submit" value="Submit">
</form>
</body>
</html>
When I hit the submit button I get below error-
{"":["The input was not valid."]}
Configurations in Startup class-
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
services.AddSingleton<IConfiguration>(Configuration);
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseMvc();
}
This only happens for POST request. GET request works fine. Same issue when testing in Postman REST client. Any help please? Please let me know if I can provide more details.
8 answers
solution1
37 ACCPTED 2018-07-06 14:00:27
Don't use FromBody . You're submitting as x-www-form-urlencoded (ie standard HTML form post). The FromBody attribute is for JSON/XML.
You cannot handle both standard form submits and JSON/XML request bodies from the same action. If you need to request the action both ways, you'll need two separate endpoints, one with the param decorated with FromBody and one without. There is no other way. The actual functionality of your action can be factored out into a private method that both actions can utilize, to reduce code duplication.
solution2
14 2018-07-31 22:29:32
I just worked through a similar situation here; I was able to use the [FromBody] without any issues:
public class MyController : Controller
{
[HttpPost]
public async Task<IActionResult> SomeEndpoint([FromBody]Payload inPayload)
{
...
}
}
public class Payload
{
public string SomeString { get; set; }
public int SomeInt { get; set; }
}
The challenge I figured out was the ensure that the requests were being made with the Content-Type header set as "application/json". Using Postman my original request was returned as "The input was not valid." Adding the Content-Type header fixed the issue for me.
solution3
11 2018-12-25 20:59:40
Just change [FromBody] to [FromForm] .
The FromForm attribute is for incoming data from a submitted form sent by the content type application/x-www-url-formencoded while the FromBody will parse the model the default way, which in most cases are sent by the content type application/json , from the request body.
Thanks to https://stackoverflow.com/a/50454145/5541434
solution4
2 2019-09-11 21:51:49
i have the same problem my solution was disable de attribute ApiController i dont know why you could read this [ https://docs.microsoft.com/en-us/aspnet/core/web-api/?view=aspnetcore-2.2#multipartform-data-request-inference] i dont understend what is the problem
[Produces("application/json")]
[Route("api/[controller]")]
//[ApiController]<<remove this
public class PagosController : ControllerBase
and you method
[HttpPost("UploadDescuento")]
public async Task<IActionResult> UploadDescuento(IEnumerable<IFormFile> files)
solution5
0 2018-07-06 13:43:09
Like mjwills and DavidG said, you should probably use a concrete class in your controller parameter implementation, something like:
public class MyClass
{
public string PropertyA { get; set; }
public string PropertyB { get; set; }
}
solution6
0 2018-07-06 13:43:35
If you inspect the network tab on your browser, you will notice that your form is sending the input values as parameters to your url, not sending itself . So naming it value won't send a property called "value" to your server.
Instead, the post method is expecting a property called value , which can be of any type (since it's an Object), and that parameter is never being fulfilled, as it is receiving these other parameters: PropertyA, PropertyB and Files.
Your full post url should probably look like this right now:
https://localhost:44352/api/tool?PropertyA=X&PropertyB=Y&Files=Z
Also notice that you did not specify an url to your Post method, so Im not sure how the client will reach /api/Tool . You probably need to specify that url on your controller, adding the Route attribute:
[Route("api/tool")]
The natural route, otherwise, is Hostname/Controller/Method or https://localhost:44352/api/post , if your controller is named Api. Otherwise it will replace "api" by the controller's name.
solution7
0 2019-07-29 14:09:17
将正文文本类型更改为所需的格式，例如从文本更改为 JSON（应用程序）。
solution8
0 2020-09-15 00:02:29
JavaScript and DotNet Core Web API implementation. Hope this helps someone out there.
//JavaScript
var dataList = [];
var dataObject = {};
dataObject["field1"] = "field1";
dataObject["field2"] = "field2";
dataList.push(dataObject);
$.ajax("https://localhost:1111/api/Sample",
{
type: "POST",
async: false,
contentType: "application/json",
dataType: 'json',
data: JSON.stringify(dataList),
success: function (responseObject) {
console.log(responseObject);
}
});
//DOT NET CORE WEB API
//Sample Request Model
public class RequestObject{
public string field1 { get; set; }
public string field2 { get; set; }
}
[Route("api/[controller]")]
[ApiController]
public class SampleController : ControllerBase
{
//Sample POST API
[HttpPost]
public string Post([FromBody] List<RequestObject> requestObjectList)
{
var youWelcome = requestObjectList;
return "JavaScript Post Successful.";
}
}
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