How to resize columns in QTreeWidget to the minimum space required

Question

I am a student programmer and I am using Qt to build a GUI interface for work. I have a QTreeWidget that has a total of 8 Columns. The input that needs to be en

Answer 1

This minimal example works for me:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QVBoxLayout *layout = new QVBoxLayout(centralWidget());
    QTreeWidget *tree = new QTreeWidget(this);
    layout->addWidget(tree);

    tree->setColumnCount(3);

    QStringList first, second, third;
    first  << "xxxxxxxxx"      << "xxxxxxxxxxxxx"     << "xxxxxxxx";
    second << "xxxxx"          << "xxxxxxxxxxxxxxxxx" << "xxxxx";
    third  << "xxxxxxxxxxxxxx" << "xxxxxxxxxx"        << "xxxxxxxx";

    tree->insertTopLevelItem(0, new QTreeWidgetItem(first));
    tree->insertTopLevelItem(0, new QTreeWidgetItem(second));
    tree->insertTopLevelItem(0, new QTreeWidgetItem(third));

    for(int i = 0; i < 3; i++)
        tree->resizeColumnToContents(i);
}

All you need to do is call the resizeColumnToContents() method once for every column after you populate the view. Let me know if the problem persists.

Answer 2

The problem for me was that StretchLastSection was set to true and if this value is set to true, this property will override the resize mode set on the last section in the header.

Solution:

_treeWidget = new UIWidgetSceneTree();
_treeWidget->header()->setStretchLastSection(false);
_treeWidget->header()->setSectionResizeMode(QHeaderView::ResizeToContents);