how to delete dynamically created widget, when "clear" button pressed?

[Spitfire]

Show/Hide approach won't work when number of widgets to show is unknown/changing.
It's a common approach in this case to create new elements rather than show part of predefined set.

you could connect the clear() signal (e.g. clicked() from the clear button) to deleteLater() on each of the created UI elements

Imho that's perfectly fine and that's how I would do it. Only thing to remember here is NOT to keep any pointers to those objects.

[aurora]

Guys....would u mind to tell what i need to do now please ? i'm confused.....
without pointer means...i think its impossible...

[Spitfire]

Try something like that:

mainwindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QtGui/QMainWindow>
 
class QVBoxLayout;
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public slots:
    void addRow( void );
 
public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
private:
    QVBoxLayout* m_layout;
};
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtGui/QMainWindow>

class QVBoxLayout;

class MainWindow : public QMainWindow
{
    Q_OBJECT

public slots:
    void addRow( void );

public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    QVBoxLayout* m_layout;
};

#endif // MAINWINDOW_H

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mainwindow.cpp

#include "mainwindow.h"
 
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QPushButton>
#include <QLineEdit>
 
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent),
    m_layout( new QVBoxLayout() )
{
    QPushButton* add = new QPushButton("Add");
    connect(add, SIGNAL(clicked()), this, SLOT(addRow()));
 
    m_layout->addWidget(add);
    m_layout->setAlignment(Qt::AlignTop);
 
    QWidget* w = new QWidget();
    w->setLayout(m_layout);
 
    this->setCentralWidget(w);
}
 
MainWindow::~MainWindow()
{
 
}
 
void MainWindow::addRow( void )
{
    QLineEdit* line = new QLineEdit();
    QPushButton* clear = new QPushButton("Clear");
    QPushButton* remove = new QPushButton("Remove");
 
    QHBoxLayout* layout = new QHBoxLayout();
    layout->setMargin(0);
    layout->addWidget(line);
    layout->addWidget(clear);
    layout->addWidget(remove);
 
    QWidget* w = new QWidget();
    w->setLayout(layout);
 
    connect(clear, SIGNAL(clicked()), line, SLOT(clear()));
    connect(remove, SIGNAL(clicked()), w, SLOT(deleteLater()));
 
    m_layout->addWidget(w);
}

#include "mainwindow.h"

#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QPushButton>
#include <QLineEdit>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent),
    m_layout( new QVBoxLayout() )
{
    QPushButton* add = new QPushButton("Add");
    connect(add, SIGNAL(clicked()), this, SLOT(addRow()));

    m_layout->addWidget(add);
    m_layout->setAlignment(Qt::AlignTop);

    QWidget* w = new QWidget();
    w->setLayout(m_layout);

    this->setCentralWidget(w);
}

MainWindow::~MainWindow()
{

}

void MainWindow::addRow( void )
{
    QLineEdit* line = new QLineEdit();
    QPushButton* clear = new QPushButton("Clear");
    QPushButton* remove = new QPushButton("Remove");

    QHBoxLayout* layout = new QHBoxLayout();
    layout->setMargin(0);
    layout->addWidget(line);
    layout->addWidget(clear);
    layout->addWidget(remove);

    QWidget* w = new QWidget();
    w->setLayout(layout);

    connect(clear, SIGNAL(clicked()), line, SLOT(clear()));
    connect(remove, SIGNAL(clicked()), w, SLOT(deleteLater()));

    m_layout->addWidget(w);
}

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It should work exacly as you want it.

[aurora]

thank u so much.....but i wanted to include that form inside another form which is designed using "FORM DESIGNER".....
SO I changed it as follows.....but i'm getting error!!! please help me to know wher i'm going wrong...

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent),
  ui(new Ui::MainWindow),
m_layout( new QVBoxLayout() )
{
    ui->setupUi(this);
QPushButton* add = new QPushButton("Add");
connect(add, SIGNAL(clicked()), this, SLOT(addRow()));
 
m_layout->addWidget(add);
.............
.............

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent),
  ui(new Ui::MainWindow),
m_layout( new QVBoxLayout() )
{
    ui->setupUi(this);
QPushButton* add = new QPushButton("Add");
connect(add, SIGNAL(clicked()), this, SLOT(addRow()));

m_layout->addWidget(add);
.............
.............

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After compiling, i got error......All errors are respect to my declaration..."MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent),
ui(new Ui::MainWindow),"

error: class 'MainWindow' does not have any field named 'ui'
error: invalid use of incomplete type 'struct Ui::MainWindow'
error: forward declaration of 'struct Ui::MainWindow'
error: 'ui' was not declared in this scope

[Spitfire]

You're probably missing

#include "ui_mainwindow.h"

#include "ui_mainwindow.h"

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