unable to send json data in c#

Question

I am sending my JSON string to this url http://myipaddress/WindowsApp/Registration?data=

I am using the following code which is as follows :

internal static async Task<String> getHttpResponse(HttpWebRequest request,string postData)
{
 String received = null;
 byte[] requestBody = Encoding.UTF8.GetBytes(postData);
 using(var postStream=await request.GetRequestStreamAsync())
 {
 await postStream.WriteAsync(requestBody, 0, requestBody.Length);
 }
 try
 {
 var response = (HttpWebResponse)await request.GetResponseAsync();
 if(response != null)
 {
 var reader = new StreamReader(response.GetResponseStream());
 received = await reader.ReadToEndAsync();
 }
 }
 catch(WebException ae)
 {
 var reader = new StreamReader(ae.Response.GetResponseStream());
 string responseString = reader.ToString();
 Debug.WriteLine("################ EXCEPTIONAL RESPONSE STRING ################");
 Debug.WriteLine(responseString);
 return responseString;
 }
 return received;
}

and I am calling this method when I click on one of my buttons in XAML as follows :

 HttpWebRequest request = HttpWebRequest.Create(Classes.Constants.SERVER_URL) as HttpWebRequest;
request.Method = "POST";
request.ContentType = "application/json";
postData = JsonConvert.SerializeObject(user); 
string receivedString = await getHttpResponse(request, postData);
Debug.WriteLine("############# RECEIVED STRING #############");
Debug.WriteLine(receivedString);

So, the problem I am facing is that I am unable to get the string on the server.

Note : I am able to get the json string when my server implements its method with a url : http://myipaddress/WindowsApp/Registration (without parameter "?data=") and also sends me response string. But fails when the term "?data=" is implemented and used in the server url.

So what am I going wrong in my code? Please help.

• TehBoyan: do you expect a parameter to be in the query string? Is that why you have data= in there?
• Random Dev: usually after ?data= you have to put your parameter/argument-value like ?data=42
• Random Dev: btw: have you tried using the debugger / some logging on your server-site to see if you get an valid request and how your server responses? What if you try 3rd party tools like Postman?
• Vinod Kulkarni: Yes. I am able to hit the server but my server gets null value. And my response string in c# code receives nothing. So what is the procedure of sending the json string with this parameter
• Random Dev: well you did not give the parameter so yeah null or an empty string is expected here ....

Answer 1

So, from what I see in the code you posted, from client side perspective(since we don't see the server side code)you are sending a request to the server in the body of the request.

There are two ways to POST: one way in the body of the request, the other one in the query string.

Seems to me that you are mixing the two.

When you do a POST request to your server to the address without the ?data= then you send the request in the body.

Solutions:

• If you want to POST in the body of the request, POST to the address without the ?data= parameter in the query string

• If you want to send it trough the query string, you need to add the value after the ?data=

something like:

http://myipaddress/WindowsApp/Registration?data=MyValue

• Vinod Kulkarni: ok but will you please show me a demo code for this? Because I guess I am lacking enough in this concept.
• Random Dev: you said yourself, that it works if you don't add the ?data= ... why do you want to add this anyway?
• Vinod Kulkarni: Because actually in future my server is gonna use this type of implementation where it will be having multiple parameters.
• TehBoyan: Exactly @CarstenKönig is right, but it might also be just a workaround. It seems that you need to study the server side in a little more detail, and what it expects. You might get by to POST your Json to it, but it might expect some sort of ?data= parameter as well, that you might need to pass in as a query string. I don't know since I don't know the server side specs.
• Random Dev: if it is in "the future" it makes no sense to add an incomplete query right now (don't you agree) - most likely your web-framework will first look at the query-strings and therefore assume your data to be null (also since it's JSON you can always add your desired parameters there instead)

Answer 2

If I have understood everything correctly, you are trying to send a POST request to the server and to get a response from the server?

The POST request methods documentation says, that POST request must be used to submit data, not to get a response.

Note that query strings (name/value pairs) is sent in the HTTP message body of a POST request like this:

POST /test/demo_form.asp HTTP/1.1
Host: w3schools.com
name1=value1&name2=value2

• Alexandre Ostapenko: But the answer should be 200/OK, she server should not send back anything esle. There is a difference between you can and you should :D

Answer 3

Your Url should be http://myipaddress/WindowsApp/Registration since you are posting your data in the payload.