Can't able to send json data to C# api in winform

Suman Raj

Am unable to post json data to api using c# winform with parameter jsondata, the following steps i used to send data every time i tried same issue raising the code & errors are attached to this post.

URL & Datas as follows:

url: https:\\xxx.com\:jsondata

Step 1:

jsondata=

[{

"Name": "Raj",

"Mobile": "5546546556"

{

"Name": "Raj",

"Mobile": "5546546546"

}

]

Step 2:

jsondata=

{

"Name": "Raj",

"Mobile": "5546546526"

}

ERROR:

{"status":"FAILURE","Error":"A JSONObject text must begin with '{' at character 1 of &"}

Error Image:

Code in C#:

public static async Task CallInvoiceAPI(string jsondata, string url)
{
try
{
HttpClient client = new HttpClient();
var response = client.PostAsJsonAsync(url, jsondata).Result;
var content = response.Content;
var result = await content.ReadAsStringAsync();
if (result.Contains("SUCCESS"))
strStatus = "Success";
else
strStatus = "Failed";
}
catch (Exception ex)
{
strStatus = "Failed";
}
}

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Suman Raj5y ago
public static async Task CallIAPI(List stud, string url)
{
httpclient client=new httpclient();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var response = client.PostAsJsonAsync(url, stud).Result;
var content = response.Content;
var result = await content.ReadAsStringAsync();
if (result.Contains("SUCCESS"))
strStatus = "Success";
else
strStatus = "Failed";
}

i tried like this also
Kiran Mohanty
+1
Kiran Mohanty5y ago
Basically , Http client is complaining about JSON input (which is of string type, not JSON). The API is receiving JSON data in string format.
CallInvoiceAPI(string jsondata, string url)
Before you make a HTTP client call, parse the string input value to JSON format or make the input parameter as type of custom object.
+1
Suman Raj5y ago
Is url correct https:\\xxxx\api\:jsondata xxxx-denote url location which is hidden :jsondata for parameter

Same issue When i tried this method

THE URL ends with https:\\xxxx\api\:jsondata
+1
Sachin Singh5y ago
instead send a list and set media type to json , it will automatically convert into appropriate json
public class Customer
{
public string Name {get;set;}
public int Mobile {get;set;}
}


public static async Task CallInvoiceAPI(string jsondata, string url)
{

    try
    {

        HttpClient client = new HttpClient();

        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        List custs=new List(){
        new Customer(){
        "Name": "Raj",
        "Mobile": "5546546556"
        },
        new Customer(){
        "Name": "Raj",
        "Mobile": "5546546546"
        }

        };

        var response = client.PostAsJsonAsync(url, custs).Result;

        var content = response.Content;


        var result = await content.ReadAsStringAsync();


        if (result.Contains("SUCCESS"))

        strStatus = "Success";

        else

        strStatus = "Failed";


    }
    catch (Exception ex)
    {

        strStatus = "Failed";

    }

}
0