Stuck in this Error :::invalid use of incomplete type ‘class Ui::Dialog’ ui(new Ui::Dialog) ^~~~~~

[jsulm]

@sankarapandiyan This is not what we asked you to provide!
AGAIN: post the content of ui_dialog.h ! It is a normal C++ header file, so symply copy its text and post it here directly...

[sankarapandiyan]

@jsulm ```
code_text

#define DIALOG_H

#include <QDialog>
#include<QTimer>
#include<QProgressDialog>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = nullptr);
    ~Dialog();
public slots:
    void myfunction();
    void perform();
    void cancel();

private:
    Ui::Dialog *ui;
    int steps;
    QProgressDialog*pd;
    QTimer*timer;
};

#endif // DIALOG_H
This is the hedder file of dialog.h

[jsulm]

@sankarapandiyan Sorry I will stop here as I'm tired to explain that you simply need to copy text from ui_dialog.h and paste it here...

[sankarapandiyan]

@jsulm i didnt have a content of ui dialog . h , And i am having dialog.h file only is there thats why i have uploaded repeatedly

[J.Hilk]

@sankarapandiyan
it will not be inside QtCreator as it is a automatically created file.

But you will find in in your build directory, if you use a normal file explorer, the one that comes with your operating system

[sankarapandiyan]

This post is deleted!

[mrjj]

@sankarapandiyan
Nope thats the actual UI file
its
ui_dialog.h
we are after to see if its broken somehow.
Its auto generated file and lives in the build folder
not in project folder.

[sankarapandiyan]

Thanks a lot ... @mrjj ... Finally ,Here there is a code of ui.dialog.h file , @J-Hilk @jsulm

** Form generated from reading UI file 'dialog.ui'
**
** Created by: Qt User Interface Compiler version 5.10.1
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

#ifndef UI_DIALOG_H
#define UI_DIALOG_H

#include <QtCore/QVariant>
#include <QtWidgets/QAction>
#include <QtWidgets/QApplication>
#include <QtWidgets/QButtonGroup>
#include <QtWidgets/QDialog>
#include <QtWidgets/QGridLayout>
#include <QtWidgets/QHeaderView>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QSpacerItem>

QT_BEGIN_NAMESPACE

class Ui_Dialog
{
public:
    QGridLayout *gridLayout;
    QPushButton *pushButton;
    QPushButton *modelessButton;
    QPushButton *modalButton;
    QSpacerItem *verticalSpacer;

    void setupUi(QDialog *Dialog)
    {
        if (Dialog->objectName().isEmpty())
            Dialog->setObjectName(QStringLiteral("Dialog"));
        Dialog->resize(304, 95);
        gridLayout = new QGridLayout(Dialog);
        gridLayout->setSpacing(6);
        gridLayout->setContentsMargins(11, 11, 11, 11);
        gridLayout->setObjectName(QStringLiteral("gridLayout"));
        pushButton = new QPushButton(Dialog);
        pushButton->setObjectName(QStringLiteral("pushButton"));

        gridLayout->addWidget(pushButton, 2, 1, 1, 1);

        modelessButton = new QPushButton(Dialog);
        modelessButton->setObjectName(QStringLiteral("modelessButton"));

        gridLayout->addWidget(modelessButton, 0, 1, 1, 1);

        modalButton = new QPushButton(Dialog);
        modalButton->setObjectName(QStringLiteral("modalButton"));

        gridLayout->addWidget(modalButton, 0, 0, 1, 1);

        verticalSpacer = new QSpacerItem(20, 40, QSizePolicy::Minimum, QSizePolicy::Expanding);

        gridLayout->addItem(verticalSpacer, 1, 1, 1, 1);


        retranslateUi(Dialog);
        QObject::connect(pushButton, SIGNAL(clicked()), Dialog, SLOT(close()));

        QMetaObject::connectSlotsByName(Dialog);
    } // setupUi

    void retranslateUi(QDialog *Dialog)
    {
        Dialog->setWindowTitle(QApplication::translate("Dialog", "QProgressDialog Launcher", nullptr));
        pushButton->setText(QApplication::translate("Dialog", "Cancel", nullptr));
        modelessButton->setText(QApplication::translate("Dialog", "Modeless", nullptr));
        modalButton->setText(QApplication::translate("Dialog", "Modal", nullptr));
    } // retranslateUi

};

namespace Ui {
    class Dialog: public Ui_Dialog {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_DIALOG_H
code_text

[jsulm]

@sankarapandiyan OK, the file looks good.
Try to do a complete rebuild:

• Delete the content of the build directory
• Run qmake
• And build

[sankarapandiyan]

Yes it Run Thanks a Lot ..