Qt Grid Layout doesn't fit into Scroll Area [duplicate] - c++

Question

This question already has an answer here:
QScrollArea missing Scrollbar
(1 answer)
Closed 1 year ago.
I am trying to put a grid view that will contain some buttons into a scroll area but I don't know why the grid layout only fits into the initial size of the scroll area (it doesn't go downside so I could use the scroll bar to see all elements).
ui->scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
QGridLayout* lay=new QGridLayout(this);
QPushButton *name[100];
for(int i=0;i<10;i++){
QString str1="project"+QString::number(i);
QString str2="3/6task";
QString str3="ALEX";
name[i]=new QPushButton(str1);
name[i]->setObjectName("btn_1");
name[i]->setStyleSheet("QPushButton#btn_1{background:transparent;Text-align:left;font-family:century gothic;font-size:18px;color:red;}"
"QPushButton#btn_1:hover{color:yellow;Font-size:22px;}");
name[i]->setFixedSize(100,40);
lay->addWidget(name[i]);
}
ui->scrollArea->setLayout(lay);
The result is in the next photo:

Answer 1

I fixed it by this way:
ui->scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
QGridLayout *lay = new QGridLayout(ui->centralwidget);
lay->addWidget(ui->scrollArea, 0, 0, 1, 1);
auto gridLayout = new QGridLayout(ui->scrollAreaWidgetContents);
gridLayout->setObjectName(QString::fromUtf8("gridLayout"));
auto widget = new QWidget(ui->scrollAreaWidgetContents);
widget->setObjectName(QString::fromUtf8("widget"));
auto gridLayout_2 = new QGridLayout(widget);
gridLayout_2->setObjectName(QString::fromUtf8("gridLayout_2"));
gridLayout->addWidget(widget, 0, 0, 1, 1);
for (int i = 0; i < 10; i++)
{
QString str1 = "project" + QString::number(i);
QString str2 = "3/6task";
QString str3 = "ALEX";
QPushButton *btn = new QPushButton(str1);
btn->setObjectName(QString("btn_%1").arg(i));
btn->setStyleSheet("QPushButton#btn_1{background:transparent;Text-align:left;font-family:century gothic;font-size:18px;color:red;}"
"QPushButton#btn_1:hover{color:yellow;Font-size:22px;}");
btn->setFixedSize(100, 40);
widget->layout()->addWidget(btn);
}
}

Answer 2

You have to use the following code:
This code has been tested.
QScrollArea* scroll = new QScrollArea(this);
scroll->setGeometry(50,0,250,300);
scroll->setWidgetResizable(true);
QWidget *container = new QWidget;
scroll->setWidget(container);
QGridLayout* lay = new QGridLayout(container);
QPushButton *name[100];
for(int i = 0; i < 20; ++i) {
name[i]=new QPushButton(scroll);
lay->addWidget(name[i]);
}
Of cource you can modify the button and the scrollArea as well.
There is no problem of using ui->scrollArea

Answer 3

Your applying the QGridLayout to the QScollArea when you actually need to apply it to a QWidget managed by the scroll area using QScrollArea::setWidget...
#include <QApplication>
#include <QGridLayout>
#include <QPushButton>
#include <QScrollArea>
#include <QString>
#include <QWidget>
int main (int argc, char **argv)
{
QApplication app(argc, argv);
QScrollArea scroll_area;
scroll_area.setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
QWidget viewport;
QGridLayout layout(&viewport);
for (int i = 0; i < 10; ++i) {
QString str1 = "project" + QString::number(i);
QString str2 = "3/6task";
QString str3 = "ALEX";
auto *pb = new QPushButton(str1);
pb->setObjectName("btn_1");
pb->setStyleSheet("QPushButton#btn_1{background:transparent;Text-align:left;font-family:century gothic;font-size:18px;color:red;}"
"QPushButton#btn_1:hover{color:yellow;Font-size:22px;}");
pb->setFixedSize(100,40);
layout.addWidget(pb);
}
scroll_area.setWidget(&viewport);
scroll_area.show();
return app.exec();
}