Error while trying to read from a Json file in c#

Question

I'm trying to read this Json file (types.json):

{
  "types": [
    "serveur d'application",
    "serveur de donnees",
    "serveur de proxy"
  ]
}

with the following function in my controller:

[HttpGet("/types")]
public async Task<ActionResult<Types>> GetInstancesTypes()
{
    Types typesGet; 
    using (StreamReader r = new StreamReader("../types.json"))
    {
        string json = r.ReadToEnd();
        typesGet = JsonConvert.DeserializeObject<Types>(json);
    }

    return typesGet;
}

The class Types is:

public class Types
    {
        public IList<string> types { get; set; }
    }

When I go to the link where I should see the result it gives me this error:

{
    "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1",
    "title": "One or more validation errors occurred.",
    "status": 400,
    "traceId": "|b6dd40c-4159a247507490ac.",
    "errors": {
        "id": [
            "The value 'types' is not valid."
        ]
    }
}

Any help would be appreciated thank you :)

Side note: why do you use a StreamReader if you're calling `ReadToEnd`? Why not just use `File.ReadAllText()` and ditch the StreamReader? — gunr2171, Mar 13 '20 at 14:56
Tip: to figure out the exact error you're getting you'll want to turn on [Common Language Runtime Exceptions](https://stackoverflow.com/a/116913/1043380). — gunr2171, Mar 13 '20 at 14:59
Also, if anyone has an idea on how can I read data from a Json file and show it on the browser ? — Hasagiii, Mar 13 '20 at 15:44
Are you sure, that's the code that's executed? You posted an http response code 400. That happens when the request data is invalid but your action does not accept any data. What happens if you set a breakpoint in first line of action? Does it ever reach this point? — Christoph Lütjen, Mar 13 '20 at 16:00
Nop I tried it doesnt reach the function that's why m a little bit confused — Hasagiii, Mar 13 '20 at 16:08
It guess it's a routing issue and you're invoking a different action than you expect. Is there something that takes an argument "types"? — Christoph Lütjen, Mar 13 '20 at 16:20

Clint · Accepted Answer · 2020-03-13T16:36:54.333

Also, if anyone has an idea on how can I read data from a Json file and show it on the browser ?

I tried your json module and it works fine, as stated in one of the comment, its a routing problem

Controller

public async Task<ActionResult<Types>> Index()
{
var path = @"C:\Users\John\URLShortnet\CoreApp1\types.json";
Types typesGet;
using (StreamReader r = new StreamReader(path))
{
string json = r.ReadToEnd();
typesGet = JsonConvert.DeserializeObject<Types>(json);
}


// return typesGet;

return View(typesGet);
}

View (Index.cshtml)


@foreach (var item in Model.types)
{
<p>@item</p>
}

Error while trying to read from a Json file in c#

1 Answers1