如何在 QTreeView 的第二列中添加项目

Question

Code explain:

First I create the items, next I define the 1st column structure and finally I try to define the 2nd column structure.

For the first column structure I use appendRow() method to QStandardItems.

For the second column structure I use setItem() method to the QStandardItemModel.

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

    // QStandardItemModel
    treeModel = new QStandardItemModel(this);

    // Create Items
    QStandardItem *item_0 = new QStandardItem("Item 0");
    QStandardItem *item_0_0 = new QStandardItem("Item 0_0");
    QStandardItem *item_1 = new QStandardItem("Item 1");
    QStandardItem *item_1_0 = new QStandardItem("Item 1_0");
    QStandardItem *item_1_0_0 = new QStandardItem("Item 1_0_0");

    QStandardItem *item_2 = new QStandardItem("Item 2");
    QStandardItem *item_3 = new QStandardItem("Item 3");

    // Root Item
    QStandardItem * rootItem = treeModel->invisibleRootItem();

    //Define the tree structure
    rootItem->appendRow(item_0);
    rootItem->appendRow(item_1);

    item_0->appendRow(item_0_0);

    item_1->appendRow(item_1_0);
    item_1_0->appendRow(item_1_0_0);

    //Define 2nd column structure
    treeModel->setItem(0,1,item_2);
    treeModel->setItem(1,1,item_3);

    // QTreeView
    ui->treeView->setModel(treeModel); 

}   

This code result in the image below. But what I want is to have Item3 just below Item2.

Answer 1

There are many ways to achieve your desired behavior, but the following is maybe the one being most straightforward. I suggest, that you study carefully the Qt docs. A good idea is to take the QTreeView instead of the QTreeWidget , which is kind of less flexible.

It might take some time to fully grasp the MVC concept in Qt, but it is worth the effort. Here goes my solution.

#include <QApplication>
#include <QStandardItemModel>
#include <QTreeView>

int main(int argc, char** args) {
    QApplication app(argc, args);
    auto model=new QStandardItemModel;

    // Create Items
    QStandardItem *item_0 = new QStandardItem("Item 0");
    QStandardItem *item_0_0 = new QStandardItem("Item 0_0");
    QStandardItem *item_1 = new QStandardItem("Item 1");
    QStandardItem *item_1_0 = new QStandardItem("Item 1_0");
    QStandardItem *item_1_0_0 = new QStandardItem("Item 1_0_0");

    QStandardItem *item_2 = new QStandardItem("Item 2");
    QStandardItem *item_3 = new QStandardItem("Item 3");

    // Root Item
    QStandardItem * rootItem = model->invisibleRootItem();

    //Define the tree structure
    rootItem->appendRow(item_0);
    rootItem->appendRow(item_1);

    item_0->appendRow(QList<QStandardItem*>{item_0_0,item_2});
    item_1->appendRow(item_1_0);
    item_1_0->appendRow(item_1_0_0);
    model->setItem(1,1,item_3);

    auto view=new QTreeView;
    view->setModel(model);
    view->show();
    app.exec();
}