added send and update of power state

mainwindow.h

@@ -23,15 +23,19 @@ protected:
 
 private slots:
     void on_btn_onoff_clicked();
-
+    void replyFinished();
     void on_txt_address_textEdited(const QString &arg1);
 
 private:
     Ui::MainWindow *ui;
-    QString sendCommand(QString cmd);
 
     QString mAddress;
-    QNetworkAccessManager *manager;
+    QNetworkReply *mReply;
+
+    bool mPowered = false;
+
+    void sendCommand(QString cmd);
+    void updateUi();
 };
 
 }