Sending custom string with header HttpWebRequest

Question

I am making a web request to login to an api. To authenticate the requested user, the api uses a string contained in the request. However, I cannot work out how to write this data to the request. I have used HTTP Live headers on firefox to find the request string and it gave me the following:

http://x/api/login

POST /api/login HTTP/1.1
Host: x
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:30.0) Gecko/20100101 Firefox/30.0
Accept: */*
Accept-Language: en-gb,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Referer: http://x/
Content-Length: 36
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache
username=xxxxxx&password=xxxxxxx - HOW DO I SET THIS

I am wondering how to send a request with the bottom line included.

My current code is this:

apiReq.GetRequestStream().Write(Encoding.ASCII.GetBytes("username=" + username + "password=" + password), 0, Encoding.ASCII.GetBytes("username=" + username + "password=" + password).Length)

But it doesn't work...

Answer 1

Here's one way:

        Dim webRequest = System.Net.HttpWebRequest.Create(YourURLHere)

        webRequest.Method = "POST"

        'If you are using credentials
        webRequest.Credentials = New NetworkCredential("Username", "Password")

        'Or if you just need to pass it in the request string
        Dim postString as String = "username=Username&password=Password"
        webRequest.ContentLength = postString.Length
        webRequest.ContentType = "application/x-www-form-urlencoded"
        Dim requestWriter As StreamWriter = New StreamWriter(webRequest.GetRequestStream())
        requestWriter.Write(postString)
        requestWriter.Close()

        Dim responseReader As StreamReader = New StreamReader(webRequest.GetResponse().GetResponseStream())
        Dim responseData As String = responseReader.ReadToEnd()

        responseReader.Close()
        webRequest.GetResponse().Close()

        'responseData contains the response from the server