How can i stop a thread running in my Dialog Class from my mainWindow
-
My mainwindow looks like this
it is a qlistwidget with some Job items, whenever any job item is clicked , it shows up the QDialogbox which looks like this.
The QDialog has a listwidget and a show button, whenever the show button is clicked , a list of 10000 possible employees will show up in the Qlistwidget and these employees are calculated by this function which is in a thread3.
```void KeyComd::Print_Descendants_key(IUIAutomation* pUIAutomation, IUIAutomationElement* pParent, int indent)
{
///Function which appends 1000 list-items in a QListWidget called "elements_listwidget" in my QDialog.
}The usual flow is: 1) i click an item(Carwash job) in Mainwindow 2) the QDialog box shows-up,i press showbutton and list of 10000 possible employees show up 3) i select an employee jack in QDialog and click okay. 4) the Mainwindow item gets changed to "Car washing job assigned to: Jack, height 5'10, weight 86" My question is that in step-3 , even when entire 10000 elements are not loaded yet and i find my preferred employee in first 500 list items, i select it and click 'ok' on dialog box , the item in mainwindow still doesnt change until the thread3 finishes running, can i force stop or terminate thread3 ?? such that when i click okay thread3 stops, and the item in main window changes. This is my Dialog cpp file named Keycomd.cpp#include "KeyComd.h"
#include "ui_KeyComd.h"
#include <QtCore>
#include <QtGui>
#include <vector>
#include<QDebug>
#include "ExecutionContext.h"
#include "XMLParser.h"
#include "Logger.h"
#include "BlockCommand.h"
#include "UIAElementUtils.h"ExecutionContext exc;
QStringList refreshed_elements;KeyComd::KeyComd(QWidget *parent)
: QDialog(parent)
{
ui.setupUi(this);
HRESULT hr = exc.init();
}KeyComd::~KeyComd()
{
}
void KeyComd::on_showbutton_clicked()
{
ui.elements_listwidget->clear();
desktop_elements.clear();std::thread thread3(&KeyComd::Print_step, this); // Here it calls a thread, because of this thread ,the execution of "Print_Descendants_key" function happens in a separate thread from main thread thread3.detach();}
void KeyComd::Print_step()
{
Print_Descendants_key(exc.pUIAutomation, nullptr, 0);
}void KeyComd::Print_Descendants_key(IUIAutomation* pUIAutomation, IUIAutomationElement* pParent, int indent)
{
///Function which appends 10000 list-items in a QListWidget called "elements_listwidget" in my QDialog.
}my mainwindow.cpp code is#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "XMLParser.h"
#include "ExecutionContext.h"
#include "Logger.h"
#include "BlockCommand.h"
#include "UIAElementUtils.h"
#include <thread>
#include <iostream>
#include <QtWidgets/qapplication.h>
#include <QtCore>
#include <QtGui>
#include <sstream>
#include <QtWidgets/qmessagebox.h>
#include <QtWidgets/qlistwidget.h>
#include <string>
#include <string.h>
#include <cstring>
#include <chrono>
#include <QCloseEvent>
#include "Header.h"
#include <map>
#include <QtWidgets/qinputdialog.h>
#include <vector>
#include "dragsupport.h"
#include "KeyComd.h"ExecutionContext exContext;
using namespace std;
MainWindow::MainWindow(QWidget* parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
populatemaps();
ui->setupUi(this);HRESULT hr = CoInitializeEx(NULL, NULL); ExecutionContext exContext; hr = exContext.init();}
MainWindow::~MainWindow()
{
delete ui;
}void MainWindow::on_xml_scripts_textbox_itemDoubleClicked(QListWidgetItem* item)
{
KeyComd keyComd;
keyComd.exec();if (keyComd.result() == QDialog::Accepted) //when i click okay,the code inside this block gets executed { // Here when okay is clicked, i want to check if thread3 is still running and if it is then stop/terminate the thread3 which is in KeyComd.cpp file ui->qlistwidget->additem("Car washing Job assigned to: Jack , height 5'10, weight 86, age 21"); }}
-
Signals and slots, Mrs. Langdon, signals and slots.
www.classicmoviehub.com - John Wayne quote
And no, you shouldn't force-terminate a thread. You should build in preemption points that check for an exit flag and exit the thread function gracefully if the flag is set.
-
@learnist Why does your dialog start a thread in the first place? Also, you are detaching from the thread: how do you want to check then whether it is running and stop it if it does? Do not detach and make the thread object member variable.
-
@jsulm Thanks sounds like that would would work. i changed it slightly but getting some errors
is this what u are saying ??
code for mainwindow.cpp#include <QThread> #include "mainwindow.h" #include "ui_mainwindow.h" #include "XMLParser.h" #include "ExecutionContext.h" #include "Logger.h" #include "BlockCommand.h" #include "UIAElementUtils.h" #include <thread> #include <iostream> #include <QtWidgets/qapplication.h> #include <QtCore> #include <QtGui> #include <sstream> #include <QtWidgets/qmessagebox.h> #include <QtWidgets/qlistwidget.h> #include <string> #include <string.h> #include <cstring> #include <chrono> #include <QCloseEvent> #include "Header.h" #include <map> #include <QtWidgets/qinputdialog.h> #include <vector> #include "dragsupport.h" #include "KeyComd.h" ExecutionContext exContext; using namespace std; MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { populatemaps(); ui->setupUi(this); HRESULT hr = CoInitializeEx(NULL, NULL); ExecutionContext exContext; hr = exContext.init(); QThread dialog_thread; } MainWindow::~MainWindow() { delete ui; } void MainWindow::on_xml_scripts_textbox_itemDoubleClicked(QListWidgetItem* item) { KeyComd keyComd; keyComd.moveToThread(&dialog_thread); connect(&keyComd, &QDialog::Accepted, &dialog_thread, &QThread::quit); dialog_thread.start(); keyComd.exec(); if (keyComd.result() == QDialog::Accepted) //when i click okay,the code inside this block gets executed { // Here when okay is clicked, i want to check if thread3 is still running and if it is then stop/terminate the thread3 which is in KeyComd.cpp file ui->qlistwidget->additem("Car washing Job assigned to: Jack , height 5'10, weight 86, age 21"); emit keyComd.accepted(); } }code for dialogbox
#include "KeyComd.h" #include "ui_KeyComd.h" #include <QtCore> #include <QtGui> #include <vector> #include<QDebug> #include "ExecutionContext.h" #include "XMLParser.h" #include "Logger.h" #include "BlockCommand.h" #include "UIAElementUtils.h" ExecutionContext exc; QStringList refreshed_elements; KeyComd::KeyComd(QWidget *parent) : QDialog(parent) { ui.setupUi(this); HRESULT hr = exc.init(); } KeyComd::~KeyComd() { } void KeyComd::on_showbutton_clicked() { ui.elements_listwidget->clear(); desktop_elements.clear(); this->Print_Descendants_key(); } void KeyComd::Print_step() { Print_Descendants_key(exc.pUIAutomation, nullptr, 0); } void KeyComd::Print_Descendants_key(IUIAutomation* pUIAutomation, IUIAutomationElement* pParent, int indent) { ///Function which appends 10000 list-items in a QListWidget called "elements_listwidget" in my QDialog. }but i am getting an error in this line keyComd.moveToThread(&dialog_thread); saying identifier dialog_thread is undefined. in the mainwindow class.
-
@learnist said in How can i stop a thread running in my Dialog Class from my mainWindow:
QThread dialog_thread;
? This is a local variable in the constructor! Make it MEMBER variable...
"saying identifier dialog_thread is undefined. in the mainwindow class" - of course it's undefined as you do not have such a member variable only a local variable in the constructor...
-
@jsulm Thanks for correcting me ,i tried making the thread member function, still it shows this error "Here its showing an error "call of an object of a class type without appropriate operator() or conversion functions to pointer-to-function type"
for reference this is my.cpp file
#include "KeyComd.h" #include "ui_KeyComd.h" #include <QtCore> #include <QtGui> #include <vector> #include<QDebug> #include "ExecutionContext.h" #include "XMLParser.h" #include "Logger.h" #include "BlockCommand.h" #include "UIAElementUtils.h" ExecutionContext exc; QStringList refreshed_elements; KeyComd::KeyComd(QWidget *parent) : QDialog(parent) { ui.setupUi(this); HRESULT hr = exc.init(); } KeyComd::~KeyComd() { } void KeyComd::on_showbutton_clicked() { ui.elements_listwidget->clear(); desktop_elements.clear(); thread3(&KeyComd::Print_step, this); // Here its showing an error "call of an object of a class type without appropriate operator() or conversion functions to pointer-to-function type" thread3.detach(); //should i not detach here ??? } void KeyComd::Print_step() { Print_Descendants_key(exc.pUIAutomation, nullptr, 0); } void KeyComd::Print_Descendants_key(IUIAutomation* pUIAutomation, IUIAutomationElement* pParent, int indent) { ///Function which appends 1000 list-items in a QListWidget called "elements_listwidget" in my QDialog. } void KeyComd::closeEvent(QCloseEvent* event) { std::terminate(); } void KeyComd::accepted() { std::terminate(); }This is my .h file
#pragma once #include<QtWidgets/qdialog.h> #include "ui_KeyComd.h" #include <thread> #include "ExecutionContext.h" #include "XMLParser.h" #include "Logger.h" #include "BlockCommand.h" #include "UIAElementUtils.h" class KeyComd : public QDialog, public Ui::KeyComd { Q_OBJECT public: KeyComd(QWidget *parent = Q_NULLPTR); ~KeyComd(); std::thread thread3; //Here i am creating it as a member variable. std::thread *thread3; //have even tried this, still it shows an error. void Print_step(); void closeEvent(QCloseEvent* event); void accepted(); void Print_Descendants_key(IUIAutomation* pUIAutomation, IUIAutomationElement* pParent, int indent = 0); QString PrintElement_Info_key(IUIAutomationElement* pElement); private slots: void on_showbutton_clicked(); void on_buttonBox_accepted(); private: QStringList desktop_elements; Ui::KeyComd ui; }; -
@learnist said in How can i stop a thread running in my Dialog Class from my mainWindow:
thread3(&KeyComd::Print_step, this);
What is this line supposed to do? This is not valid C++ code as std::thread does not have an operator() operator.
Initialisation is done in constructors:KeyComd::KeyComd(QWidget *parent) : QDialog(parent), thread3(&KeyComd::Print_step, this) { ui.setupUi(this); HRESULT hr = exc.init(); }"//should i not detach here ???" - why?
-
@learnist please don't double post.
