POST /formapagamento

  curl -X POST "https://bling.com.br/Api/v2/formapagamento/json/"

        -d "apikey={apikey}"

        -d "xml={xml_da_forma_pagamento}"

$url = 'https://bling.com.br/Api/v2/formapagamento/json/';
$xml = '<?xml version="1.0" encoding="UTF-8"?><formapagamento>...</formapagamento>';
$posts = array (
   "apikey" => "{apikey}",
   "xml" => rawurlencode($xml)
);
$retorno = executeSendPayment($url, $posts);
echo $retorno;
function executeSendPayment($url, $data){
   $curl_handle = curl_init();
   curl_setopt($curl_handle, CURLOPT_URL, $url);
   curl_setopt($curl_handle, CURLOPT_POST, count($data));
   curl_setopt($curl_handle, CURLOPT_POSTFIELDS, $data);
   curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, TRUE);
   $response = curl_exec($curl_handle);
   curl_close($curl_handle);
   return $response;
}

public static void ExecuteSendPayment() {
   HttpWebRequest request =
      (HttpWebRequest)WebRequest.Create("https://bling.com.br/Api/v2/formapagamento/");
   ASCIIEncoding encoding = new ASCIIEncoding();
   string postData = "apikey={apiKey}&xml={xml_da_forma_pagamento}";
   byte[] data = encoding.GetBytes(postData);
   request.Method = "POST";
   request.ContentType = "application/x-www-form-urlencoded";
   request.ContentLength = data.Length;
   using (Stream stream = request.GetRequestStream())
        stream.Write(data,0,data.Length);
   HttpWebResponse response = (HttpWebResponse)request.GetResponse();
   string responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
   Console.Out.WriteLine("Response Body: \r\n {0}", responseString);
}