call the dialog inside the loop

[Blackzero]

How can I call a dialog inside a loop process, I tried this but when the dialog appears the application becomes "Not responding", how can I solve this?

void MainWindow::MyProcess()
{
    for (;;)
    {
        if (result)
        {
            // code process ....
        }
        else
        {
            // result failed
            CMessageBox dialog;
            dialog.setMessage(Critical, "Error", "Failed.", static_cast<Btn>(Ok));
            dialog.exec_();
            break;
        }
    }
}

[hskoglund]

Hi, you can try open() instead of exec() and connect to the finished() signal from the messagebox to get notified when the user pressed Ok.

[hskoglund]

Note: you'll have to create the messagebox somewhere outside the else clause, otherwise it will be destroyed when the break occurs.

[ChrisW67]

@Blackzero What is CMessageBox? The setMessage() and exec_() calls cast some doubt over whether it is a QMessageBox or similar sub-class.

[Blackzero]

@ChrisW67

#ifndef CMESSAGEBOX_H
#define CMESSAGEBOX_H

#include <QDialog>

namespace Ui {
class CMessageBox;
}

enum Mode {
   Information = 1,
   Warning = 2,
   Question = 3,
   Critical = 4
};

enum Btn {
   Yes = 0x01,
   No = 0x02,
   Ok = 0x04,
   Cancel = 0x08
};

class CMessageBox : public QDialog {
   Q_OBJECT

public:
   explicit CMessageBox(QWidget *parent = nullptr);
   ~CMessageBox();

   void setMessage(Mode modemsg, const QString &title, const QString &message, Btn modeBtn);
   void setIcon(const QString &iconPath);
   void addButton(const QString &text, Btn (CMessageBox::*handler)());

   Btn PushOk();
   Btn PushCancel();
   Btn PushYes();
   Btn PushNo();
   Btn exec_();

private:
   Ui::CMessageBox *ui;
   Btn result_value; 

};

#endif // CMESSAGEBOX_H

#include "cmessagebox.h"
#include "ui_cmessagebox.h"
#include <QFrame>

#include <QPushButton>


CMessageBox::CMessageBox(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::CMessageBox)
{
    ui->setupUi(this);
    setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);

    //this->setWindowFlags(Qt::Dialog | Qt::CustomizeWindowHint | Qt::WindowTitleHint | Qt::WindowCloseButtonHint);

    ui->frame->setFrameShape(QFrame::StyledPanel);
    ui->frame->setFrameShadow(QFrame::Raised);

}

CMessageBox::~CMessageBox()
{
    delete ui;
}

void CMessageBox::setMessage(Mode modemsg, const QString &title, const QString &message, Btn modeBtn)
{
    ui->msg->setText(message);
    this->setWindowTitle(title);

    ui->horizontalLayout_2->addItem(new QSpacerItem(40, 20, QSizePolicy::Expanding, QSizePolicy::Minimum));
    if (modeBtn & Yes) addButton("Yes", &CMessageBox::PushYes);
    if (modeBtn & Ok) addButton("OK", &CMessageBox::PushOk);
    if (modeBtn & No) addButton("No", &CMessageBox::PushNo);
    if (modeBtn & Cancel) addButton("Cancel", &CMessageBox::PushCancel);
    ui->horizontalLayout_2->addItem(new QSpacerItem(40, 20, QSizePolicy::Expanding, QSizePolicy::Minimum));
    int labelWidth = ui->msg->sizeHint().width();
    int labelHeight = ui->msg->sizeHint().height();

    setFixedWidth(labelWidth + 70);
    if (labelHeight > 39) {
        setFixedHeight(labelHeight + 64);
    } else {
        setFixedHeight(107);
    }

    switch (modemsg) {
    case Information:
        setIcon(":/img/messagebox-asterisk.png");
        break;
    case Warning:
        setIcon(":/img/messagebox-exclamation.png");
        break;
    case Question:
        setIcon(":/img/messagebox-question.png");
        break;
    case Critical:
        setIcon(":/img/cross.png");
        break;
    default:
        break;
    }
}

void CMessageBox::addButton(const QString &text, Btn (CMessageBox::*handler)())
{
    QPushButton *pushButton = new QPushButton(ui->frame);
    pushButton->setMinimumWidth(75);
    pushButton->setMaximumWidth(23);
    pushButton->setText(text);
    ui->horizontalLayout_2->addWidget(pushButton);
    connect(pushButton, &QPushButton::clicked, this, handler);
}

void CMessageBox::setIcon(const QString &iconPath)
{
    ui->icn->setStyleSheet("image: url(" + iconPath + ");");
    QApplication::beep();
}
Btn CMessageBox::PushOk() {
    result_value = Ok;
    accept();
    return result_value;
}
Btn CMessageBox::PushCancel() {
    result_value = Cancel;
    accept();
    return result_value;
}
Btn CMessageBox::PushYes() {
    result_value = Yes;
    accept();
    return result_value;
}
Btn CMessageBox::PushNo() {
    result_value = No;
    accept();
    return result_value;
}
Btn CMessageBox::exec_() {
    QDialog::exec();
    return result_value;
}

[jsulm]

@Blackzero said in call the dialog inside the loop:

but when the dialog appears the application becomes "Not responding"

But does the dialog work?
You're using exec() which means you're using the dialog as a modal dialog - the application is blocked until the dialog is closed.