从Swift发送POST时，在php文件中获取参数

Question

当我从SWIFT（登录文件）发帖时，我试图在我的php文件中获取参数

这是我的php文件：

<? 
 $json = array();
 $json['username'] = $_POST['username'];
 $json['password'] = $_POST['password'];
 $json['result'] = "false";
 $json['id_familia'] = 148;
 $json['id_centre'] = 2;
 $json['web'] = "www.cec-escolalolivar.cat";
 echo json_encode($json); 
?> 

这是快速代码（当然我已尝试过不同的选项，同步，不同步，......）

    let url : NSURL = NSURL(string: "http://www.cec-info.cat/app/config.inc.main_families_json.php")!
    let request:NSMutableURLRequest = NSMutableURLRequest(url: url as URL)
    let bodyData="data=xgubianas@gmail.com"
    request.httpMethod = "POST"
    request.httpBody = bodyData.data(using: String.Encoding.utf8)
    NSURLConnection.sendAsynchronousRequest(request as URLRequest, queue: OperationQueue.main)
    {
        (response,data,error) in
        print (response as Any)

        if let data = data{
            do {
                let json = try JSONSerialization.jsonObject(with: data, options: [])
                print (json)
            }
            catch
            {
                print (error)
            }
        }
    }