Adding code example to QT C++ -

i'd add qt example code simple project. sample code here: https://wiki.qt.io/download_data_from_url

it consists of filedownloader.cpp , filedownloader.h -- code downloads graphic supplied url.

i've added these files project , clean compile. think understand code ok (i'm c coder, not c++) don't understand how can pass qurl created project filedownloader.cpp

the "project" simple main.cpp/mainwindow.cpp/mainwindow.ui offers button pressed. pressing button calls routine below:

void mainwindow::on_pushbutton_clicked() { // pass filedownloader process qurl fileloc("http://www.test.com/test.jpg"); } 

how feed qurl fileloc filedownload.cpp?

you have add new method filedownloader, accepts qurl , starts download.

filedownloader.h:

#ifndef filedownloader_h #define filedownloader_h  #include <qobject> #include <qbytearray> #include <qnetworkaccessmanager> #include <qnetworkrequest> #include <qnetworkreply>  class filedownloader : public qobject {  q_object  public:   explicit filedownloader(qurl imageurl, qobject *parent = 0);   virtual ~filedownloader();   qbytearray downloadeddata() const;   signals:   void downloaded();   public slots:   void download(qurl url);   // <------ here   private slots:   void filedownloaded(qnetworkreply* preply);   private:   qnetworkaccessmanager m_webctrl;   qbytearray m_downloadeddata; };  #endif // filedownloader_h 

filedownloader.cpp:

#include "filedownloader.h"  filedownloader::filedownloader(qobject *parent) :  qobject(parent) {  connect(   &m_webctrl, signal (finished(qnetworkreply*)),   this, slot (filedownloaded(qnetworkreply*))   );  // <------ notice, i've removed downloading code here }  filedownloader::~filedownloader() { }  void filedownloader::filedownloaded(qnetworkreply* preply) {  m_downloadeddata = preply->readall();  //emit signal  preply->deletelater();  emit downloaded(); }  void filedownloader::download(qurl url) { // <------ , definition  qnetworkrequest request(url);  m_webctrl.get(request); }  qbytearray filedownloader::downloadeddata() const {  return m_downloadeddata; } 

and on_pushbutton_clicked this:

void mainwindow::on_pushbutton_clicked() { // pass filedownloader process qurl fileloc("http://www.test.com/test.jpg"); m_filedownloader.download(fileloc); }