Qt and QML interaction, and multithreading

To register an object to QML, implement the code:
Gamesub.h

#pragma once#include <QObject>#include <QVariant>#include <QQmlApplicationEngine>#include <QquickItem>class gamesub:p ublicQobject{Q_objectPublicgamesub(qobject* Parent=NULL); ~gamesub();Qqmlapplicationengine* M_MAINROOT;Qquickitem* M_PAGE;q_invokablevoid Setpage(qquickitem* page); void Setroot(qqmlapplicationengine* mainroot);q_invokablevoid Init();q_invokablevoid msg(qvariantvar)  ;q_invokable qvariantGetobj();};

Gamesub.cpp

#include "Gamesub.h"Gamesub::gamesub (qobject* Parent): Qobject (parent) {}gamesub::~gamesub () {}q_invokablevoidGamesub::setpage (qquickitem* page) {m_page = page; Outputdebugstringa (M_page->objectname (). tostdstring (). C_STR ());intcout =0;D Word thtest (LPVOID LP) {qquickitem* m_page = (qquickitem*) LP; Qvariant item;//blockingqueuedconnection is used in multiple threads, otherwise an error occurs    BOOLRet2 = Qmetaobject::invokemethod (M_page,"GetItem", Qt::connectiontype::blockingqueuedconnection, Q_return_arg (qvariant, item), Q_arg (Qvariant, cout));if(Ret2 = =false) {AfxMessageBox ("ERROR");    } qobject* obj; obj = Item.value<QObject*> ();///Item.typename () can be used to get the return value type, then convert using item.value< type > ()    int  var=0; while(true)    {var=var+1;if(Obj!=null && isbadwriteptr (obj,4)==false) {Qmetaobject::invokemethod (obj,"Test", Qt::connectiontype::queuedconnection, Q_arg (Qvariant, Qstring::number (var)));//can also be modified here to Qt::connectiontype::blockingqueuedconnection} Sleep ( +); }return  0;} Q_invokablevoidGamesub::init () { for(intI=0;i<5; i++) {qvariant s;        s = i; Qmetaobject::invokemethod (M_page,"Addmodel", Q_arg (Qvariant, s.tostring ()));    } qvariant ret; Qmetaobject::invokemethod (M_page,"Getlen", Q_return_arg (qvariant, ret));//afxmessagebox (Ret.typename ());AfxMessageBox (Ret.tostring (). tostdstring (). C_STR ()); Qvariant item;BOOLRet2 = Qmetaobject::invokemethod (M_page,"GetItem", Q_return_arg (Qvariant, item), Q_arg (Qvariant,0));if(Ret2 = =false) {AfxMessageBox ("ERROR");    } qobject* obj; obj = Item.value<QObject*> (); AfxMessageBox (Obj->objectname (). tostdstring (). C_STR ()); for(inti =0; I < Ret.toint ();        i++) {AfxBeginThread (Afx_threadproc (thtest), m_page); Sleep ( -);    cout++; }}voidGamesub::setroot (Qqmlapplicationengine * mainroot) {m_mainroot = Mainroot;} Q_invokablevoidGamesub::msg (qvariantvar) {AfxMessageBox (var. toString (). tostdstring (). C_STR ()); Q_invokable qvariant gamesub::getobj () {if(M_mainroot!=null) {Qobject *tmp = M_mainroot->findchild<qobject *> ("Mmodel");if(Tmp!=null) {Outputdebugstringa ("OK object"); }Else{Outputdebugstringa ("Null Object"); }    }return 0;}

Main.cpp:

//Register First for classQmlregistertype<Gamesub>("Game",1,0,"Game"); Qapplication*App=(qapplication*) qapplication:: Instance(); Outputdebugstringa ("Local File");    Qqmlapplicationengine engine (APP); Gamesub*Tmp= NewGamesub (); Tmp -M_mainroot= &Engine Engine.Rootcontext () -Setcontextproperty ("Game", (Qobject*) TMP); Engine.Load (qurl:: Fromlocalfile(Qstringliteral ("MAIN.QML")));

Click Run, C + + code dynamically add model, and in multi-threading, Refresh UI
QML file:
Main.qml

Import QtQuick2.6Import QtQuick. Window 2.2Import Material0.1As Materialimport Material. ListItems 0.1As Listitemsimport Material. Extras 0.1As Exmaterial. Applicationwindow{Property Item tmp:null visible:true title:"main Window"property var mytabs: ["Main"] theme{primarycolor:material. Palette. Colors["Blue"]["a"] Primarydarkcolor:material. Palette. Colors["Blue"][" the"] Accentcolor:material. Palette. Colors["Teal"]["a"] Tabhighlightcolor:"White"} initialpage:material. Page{id:mainpage title:"main Window"Tabs:mytabs onselectedtabchanged: {if (selectedtab==1) {Mainrun. Visible=false Loader. SOURCE=qt. Resolvedurl("RUN2.QML") Loader. Visible=true}else{Mainrun. Visible=true Loader. Visible=false}} loader{anchors. Fill: Parent Visible:false id:loader//SOURCE:QT. Resolvedurl("RUN2.QML")} Material. Button{Id:mainrun visible:true text:"Run"Elevation:1OnClicked: {mytabs[1]="In Progress"MainPage. Tabs=mytabs mainpage. Selectedtab=1text="Runing"}}} droparea{anchors. Fill: Parent ondropped: {for (Var i=0; i<drop.urls.length;i++){Title=title+drop. Text+","}            }        }}

RUN2.QML:

Import QtQuick2.6Import QtQuick. Window 2.2Import Material0.1As Materialimport Material. ListItems 0.1As Listitemsimport Material. Extras 0.1As Exmaterial. View{ID:PageObjectName: "Mmodel"Component. Ondestruction: {Console. Log("Ondestruction")} flow{spacing:5Anchors. Fill: Parent repeater{Id:rey Model:mmodel delegate:componet } Component. oncompleted: {Game. Setpage(page);Game. Init();}} listmodel{Id:mmodel listelement{txt:"Test"} listelement{txt:"Test2"} listelement{txt:"Test3"}} component{id:componet Material. View{Id:m_view ObjectName:"Index"Elevation:3Width -Height -Anchors. Margins:5column{width:parent. WidthMaterial. Button{ID:BTN Elevation:1Width:parent. WidthText:txt;} repeater{Model:mmodel2 Delegate:listitems. Standard{Valuetext:index Itemlabel. Font. Pixelsize: -Elevation:1Id:labels Text:shows}}} listmodel{Id:mmodel2 listelement{shows:"Test"}} function test (TXT) {if (Mmodel2. Count>5) {Mmodel2. Clear() Mmodel2. Sync()} Mmodel2. Append({shows:txt})} }} function GetItem (index) {var i= rey. Itemat(index) Console. Log("Index:"+index+":"+i) return I;} function Addmodel (argtxt) {Mmodel. Append({txt:argtxt})} function Getlen () {return Mmodel. Count;}}

Qt and QML interaction, and multithreading