How to Remove dynamically Added Button in QGridLayout

[Ramkumar Mohan]

This is my code ,

  #include "mainwindow.h"
  #include "ui_mainwindow.h"
  #include <QtSql/QSqlQuery>
  #include <QDebug>
  static QString array[100]={""};
  int val=0;
  int val2=0;
  int number=0;

  MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
 {
     ui->setupUi(this);
     QSqlDatabase mydb = QSqlDatabase::addDatabase("QSQLITE");
     mydb.setDatabaseName("E:/QT Offline/Qt5.12.12/GLIDelete/Bar_Data.db");
    if(!mydb.open())
  {
    qDebug() << "Can't Connect to DB !";
}
else
{
    qDebug() << "Connected Successfully to DB !";
}

}

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


 void MainWindow::on_pushButton_clicked()
 {

ui->stackedWidget->setCurrentIndex(1);
ui->gridLayout->update();
ui->tabWidget->setCurrentIndex(0);
ui->tabWidget->update();
QSqlQuery query;
query.prepare("SELECT name FROM test");
query.exec();
int count=0;
while(query.next())
{
    QString s=query.value(0).toString();
    array[count]=s;
    count++;
    //qDebug()<<s;
}
int count1=0;
const QSize btnSize = QSize(150, 50);
for (int i=0;i<15 ;i++ )
{
    for (int j=0;j<5 ;j++ )
    {
        if(count1==count)
            break;
        else
        {
            QPushButton *button = new QPushButton(array[count1]);
            button->setFixedSize(btnSize);
            button->setObjectName(array[count1]);
            connect(button, &QPushButton::clicked, this,&MainWindow::cald);
            ui->gridLayout->addWidget(button,i,j);
            count1++;

        

        }
    }
}
}

void MainWindow::cald()
{
QObject *senderObj = sender(); // This will give Sender object
QString senderObjName = senderObj->objectName();
ui->stackedWidget->setCurrentIndex(1);

}

 void MainWindow::on_pushButton_2_clicked()
 {
    ui->stackedWidget->setCurrentIndex(0);
 }


void MainWindow::on_pushButton_3_clicked()
{
ui->stackedWidget->setCurrentIndex(2);
ui->gridLayout->update();
ui->tabWidget->setCurrentIndex(0);
ui->tabWidget->update();
QSqlQuery query;
query.prepare("SELECT name FROM test");
query.exec();
int count=0;
while(query.next())
{
    QString s=query.value(0).toString();
    array[count]=s;
    count++;
}
int count1=0;
const QSize btnSize = QSize(150, 50);
for (int i=0;i<15 ;i++ )
{
    for (int j=0;j<5 ;j++ )
    {
        if(count1==count)
            break;
        else
        {
            QPushButton *button = new QPushButton(array[count1]);
            button->setFixedSize(btnSize);
            button->setObjectName(array[count1]);
            connect(button, &QPushButton::clicked, this,&MainWindow::cald2);
            ui->gridLayout_2->addWidget(button,i,j);
            val=i;
            val2=j;
            count1++;
        }
    }

}
 }


void MainWindow::cald2()
{
QObject *senderObj = sender(); // This will give Sender object
QString senderObjName = senderObj->objectName();
QLayoutItem* item = ui->gridLayout_2->itemAtPosition(val,val2);
QWidget * widget = item->widget();
int value =  ui->gridLayout_2->indexOf(widget);
QLayoutItem * it = ui->gridLayout_2->itemAt(value);
QWidget * widgets = it->widget();

while( ui->gridLayout_2->count() )
{
    qDebug()<<ui->gridLayout_2->count();
    if( widgets )
    {
        ui->gridLayout_2->removeWidget(widgets);
        delete widgets;
    }
}
QSqlQuery query;
query.prepare("Delete from test where name='"+senderObjName+"'");
if(query.exec())
{
    qDebug()<<"Deleted Test : "<<senderObjName;

}

ui->stackedWidget->setCurrentIndex(2);

 }

 void MainWindow::on_pushButton_4_clicked()
 {
   ui->stackedWidget->setCurrentIndex(0);

 }

UI Page : -

Ui->Stackedwidget->currentIndex(0);
.

Ui->Stackedwidget->currentIndex(1);

Ui->Stackedwidget->currentIndex(2);

Iam using two gridlayout in two different pages , Retrieves buttons name from database ,

query.prepare("SELECT name FROM test");

If i click on the delete button and delete it , it doesn't delete ,

how to delete it correctly,

[anil_arise]

@Ramkumar-Mohan said in How to Remove dynamically Added Button in QGridLayout:

QLayoutItem* item = ui->gridLayout_2->itemAtPosition(val,val2);

Correct way is :

QLayoutItem* item = ui->gridLayout_2->itemAtPosition(val,val2);
ui->gridLayout_2->removeItem(item);
QWidget *del_wid = item->widget();
if(del_wid)
{
delete del_wid;
}

Note : always first remove item then delete widget form any kind of layout.

[jsulm]

@Ramkumar-Mohan Just check documentation: https://doc.qt.io/qt-5/qlayout.html#takeAt