Simple use of qlistview of QT (including source code + comments)

One 、QTreeView Operation example diagram

1. Example of adding and deleting nodes

The following figure shows an example of adding and deleting nodes ; The source code is in the third section of this article （ The source code contains detailed comments ）.

2. Get and modify the value of the node

The following figure shows the operation of nodes on node values , This includes getting values 、 Set values, etc ; The source code is in the third section of this article （ The source code contains detailed comments ）.

Tips ： Can't use Qt Designer design interface partners click here

Two 、QListView（ Personal understanding ）

Similarly, we will QListView and QTableView、QTreeView comparing

1. All three are similar MVC（Model View Controller） Pattern , It all includes Delegate, Please check out Qt The realization of agent （ Button chapter ）、Qt The realization of agent （ General controls ）;
2. QListView With the other two View Different data models are used ,QListView It uses QStringListModel Storing data ;
3. QListView There is also an inheritance QListWidget Subclasses of ;
4. QListView Because the data model used is different, it can not be like the other two View It can be obtained separately Item Set it up （ To set the value, you need to use setData Function to set ）;
5. QListView Compared with the other two View Views have fewer manipulation functions ;
6. QListView It seems that the second column cannot be set for my personal use .

3、 ... and 、 Source code

CMainWindow.h

#ifndef CMAINWINDOW_H
#define CMAINWINDOW_H

#include <QMainWindow>
#include <QStringListModel> // Data model class 

namespace Ui {
    
class CMainWindow;
}

class CMainWindow : public QMainWindow
{
    
    Q_OBJECT

public:
    explicit CMainWindow(QWidget *parent = nullptr);
    ~CMainWindow();

private slots:
    /** * @brief on_removeNodeBtn_clicked  Delete button slot function  */
    void on_removeNodeBtn_clicked();

    /** * @brief on_addNodeBtn_clicked  Add button slot function  */
    void on_addNodeBtn_clicked();

    /** * @brief on_getNodeValBtn_clicked  Get value button slot function  */
    void on_getNodeValBtn_clicked();

    /** * @brief on_setNodeValBtn_clicked  Set value button slot function  */
    void on_setNodeValBtn_clicked();

private:
    Ui::CMainWindow     *ui;

    QStringListModel  *m_pModel;      // Data model object pointer 
};

#endif // CMAINWINDOW_H

CMainWindow.cpp

#include "CMainWindow.h"
#include "ui_CMainWindow.h"

CMainWindow::CMainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::CMainWindow)
{
    
    ui->setupUi(this);
    // Set the window title 
    this->setWindowTitle("QListView Simple use ");

    //=============== Data model （QStandardItemModel）===============
    // Create a string list model object space and specify the parent object 
    m_pModel = new QStringListModel(ui->listView);

    // Set the string list model to the tree view 
    ui->listView->setModel(m_pModel);
    // Add default 
    m_pModel->setStringList(QStringList()
                            << " first line "
                            << " The second line "
                            << " The third line ");

}

CMainWindow::~CMainWindow()
{
    
    //!  Destructor :
    //!  Some of my friends will find that I don't destruct model object ,
    //!  That's because I specified the parent object when I got the object space ,
    //!  When its parent object is destructed , The object whose child object is a pointer will be destructed first .
    delete ui;
}

void CMainWindow::on_removeNodeBtn_clicked()
{
    
    // Through the... Of the current position index Get the current line 
    int row = ui->listView->currentIndex().row();

    // If current behavior -1 There is no selection , Then return 
    if( -1 == row)
    {
    
        return;
    }

    // Remove current row directly 
    m_pModel->removeRow(row);
}

void CMainWindow::on_addNodeBtn_clicked()
{
    
    // Get the text to be set for the new node 
    QString str = ui->nodeValEdit->text();

    // If the node value is empty, you cannot add a direct return 
    if(str.isEmpty())
    {
    
        return;
    }

    //!  Use insert Insert row 
    //! （ Because no append function , So get it separately index Set the value ）

    // Position of the added row 
    int row = m_pModel->rowCount();
    // Insert row 
    m_pModel->insertRow(row);
    // Get the... Of the row just inserted index
    QModelIndex index = m_pModel->index(row);
    // adopt setData function 
    m_pModel->setData(index, str);

    // Set the newly added row as the current row 
    ui->listView->setCurrentIndex(index);
}

void CMainWindow::on_getNodeValBtn_clicked()
{
    
    // Get current index
    QModelIndex index = ui->listView->currentIndex();
    // If current behavior -1 There is no selection , Then return 
    if( -1 == index.row())
    {
    
        return;
    }

    //!  Set the value in the current position to the edit box 
    //! data The default value of the parameter of the function is Qt::DisplayRole, When an individual obtains the display value, it is not necessary to transfer parameters 
    ui->nodeValEdit->setText(index.data(Qt::DisplayRole).toString());
}

void CMainWindow::on_setNodeValBtn_clicked()
{
    
    // Get current index
    QModelIndex index = ui->listView->currentIndex();

    // Get the text to be set by the node 
    QString str = ui->nodeValEdit->text();

    // If current behavior -1 Or if the set string is empty, it returns 
    if( -1 == index.row() || str.isEmpty())
    {
    
        return;
    }
	
	// Set the obtained value to the current index position 
    m_pModel->setData(index, str);
}

summary

QListView At present, there are few in my practical application , So the other two are used View Sudden use QListView I'm not used to it , The main reason is QListView And the other two View The reasons for using different data model objects , That's all I have to ask now .
That's it , Good night …

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notes ： This paper summarizes the problems encountered by the author in the process of programming , The content is for reference only , If there are any mistakes, please point out .
notes ： If there is any infringement , Please contact the author for deletion