[QT]——Usage of QListWidget

Table of contents

1.QListWidget and QListWidgetItem

2. Appearance

2.1 List mode

2.2 Icon mode

3. Common interfaces

4.Example

Delete list item

Add list item

---

1.QListWidget and QListWidgetItem

QListWidget is a list box control in Qt. It is used to display multiple list items. The class corresponding to the list items is QListWidgetItem .

QListWidgetItem can contain only text

QListWidgetItem can contain both pictures and text .

2. Appearance

The list box control supports two display modes: list mode and icon mode.

2.1 List mode

setViewMode(QListView::ListMode);//设置QListWidget为列表模式

 

2.2 Icon mode

setViewMode(QListView::IconMode);//设置QListWidget为图标模式

 

3. Common interfaces

//添加列表项
void addItem(const QString &label)
void addItem(QListWidgetItem *item)
void addItems(const QStringList &labels)

//返回鼠标选中的列表项
QListWidgetItem *QListWidget::currentItem() const;
//删除窗口中的item的列表项
void QListWidget::removeItemWidget(QListWidgetItem *item)

//设置列表项中的图片大小
void QAbstractItemView::setIconSize(const QSize &size);
    
//设置列表项中的布局的大小
void QListView::setGridSize(const QSize &size)

Signal

//单击列表项
void itemClicked(QListWidgetItem *item)
//双击列表项
void itemDoubleClicked(QListWidgetItem *item)

Delete list item

Two ways to delete list items:

方式一:
QListWidgetItem* item=ui->lwprovice->currentItem();//获取当前的列表项
ui->lwprovice->removeItemWidget(item);//移除列表项
delete item;//删除列表项
方式二：
int row =ui->lwprovice->currentRow();//获取第一个列表项
QListWidgetItem* item=ui->lwprovice->takeItem(row);
delete item;

4.Example:

ui interface: 

Set "list mode" and "icon mode" transitions:

//将两个单选按钮存放到QGroupBox容器中
//保证一次只能选中一个按钮
m_checkBut=new QButtonGroup(this);
m_checkBut->addButton(ui->rbListMode,0);
m_checkBut->addButton(ui->rbiconmode,1);

connect(ui->rbListMode,&QCheckBox::clicked,this,&MainWindow::selectMode);
connect(ui->rbiconmode,&QCheckBox::clicked,this,&MainWindow::selectMode);

//槽函数
void MainWindow::selectMode()
{
  int checkedId=m_checkBut->checkedId();
  if(checkedId==0)
  {
      ui->lwprovice->setViewMode(QListView::ListMode);
  }else{
      ui->lwprovice->setViewMode(QListView::IconMode);
  }
}

 

Delete list item

    connect(ui->del_but,&QToolButton::clicked,this,[=](){
#if 0
        QListWidgetItem* item=ui->lwprovice->currentItem();
        ui->lwprovice->removeItemWidget(item);
        delete item;
#else
        int row =ui->lwprovice->currentRow();
        QListWidgetItem* item=ui->lwprovice->takeItem(row);
        delete item;
    });

Add list item

//图片的路径
QList<QString> paths={":/1",":/2",":/3"};


connect(ui->insert_but,&QToolButton::clicked,this,[=](){
        //获取随机值
        int pos=QRandomGenerator::global()->generate()%3;
        //获取图片的值
        QString name=ui->leInput->text();
        QIcon icon(paths[pos]);//设置图片
        QListWidgetItem* item=new QListWidgetItem(icon,name);
        int row =ui->lwprovice->currentRow();
        ui->lwprovice->insertItem(row+1,item);//将列表 设置 进当前鼠标的后面
 });

//将列表项添加到最后一个位置
   connect(ui->add_but,&QToolButton::clicked,this,[=](){
        qDebug()<<"插入item";
        //插入按钮
        int pos=QRandomGenerator::global()->generate()%3;

        QString name=ui->leInput->text();
        QIcon icon(paths[pos]);//设置图片
        QListWidgetItem* item=new QListWidgetItem(icon,name);
        ui->lwprovice->addItem(item);
    });

All code:

// .h文件
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include<QButtonGroup>
namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

public slots:
    void selectMode();

private:
    Ui::MainWindow *ui;
    QButtonGroup* m_checkBut;
};

#endif // MAINWINDOW_H








//  .pp文件
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QCheckBox>
#include<QList>
#include<QString>
#include<QRandomGenerator>
#include<QToolButton>
#include<QDebug>
QList<QString> paths={":/1",":/2",":/3"};

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

    m_checkBut=new QButtonGroup(this);
    m_checkBut->addButton(ui->rbListMode,0);
    m_checkBut->addButton(ui->rbiconmode,1);
    ui->rbListMode->setEnabled(true);
     ui->lwprovice->setViewMode(QListView::ListMode);

    connect(ui->rbListMode,&QCheckBox::clicked,this,&MainWindow::selectMode);
    connect(ui->rbiconmode,&QCheckBox::clicked,this,&MainWindow::selectMode);

    connect(ui->lwprovice,&QListWidget::itemClicked,this,[=](QListWidgetItem *item)
    {
        //单击列表项
        ui->lineEdit->setText(item->text());
    });

    connect(ui->add_but,&QToolButton::clicked,this,[=](){
        qDebug()<<"插入item";
        //插入按钮
        int pos=QRandomGenerator::global()->generate()%3;

        QString name=ui->leInput->text();
        QIcon icon(paths[pos]);//设置图片
        QListWidgetItem* item=new QListWidgetItem(icon,name);
        ui->lwprovice->addItem(item);
    });

    connect(ui->del_but,&QToolButton::clicked,this,[=](){
#if 0
        QListWidgetItem* item=ui->lwprovice->currentItem();
        ui->lwprovice->removeItemWidget(item);
        delete item;
#else
        int row =ui->lwprovice->currentRow();
        QListWidgetItem* item=ui->lwprovice->takeItem(row);
        delete item;
#endif
    });


    connect(ui->insert_but,&QToolButton::clicked,this,[=](){
        int pos=QRandomGenerator::global()->generate()%3;

        QString name=ui->leInput->text();
        QIcon icon(paths[pos]);//设置图片
        QListWidgetItem* item=new QListWidgetItem(icon,name);
         int row =ui->lwprovice->currentRow();
        ui->lwprovice->insertItem(row+1,item);
    });

}

void MainWindow::selectMode()
{
  int checkedId=m_checkBut->checkedId();
  if(checkedId==0)
  {
      ui->lwprovice->setViewMode(QListView::ListMode);
  }else{
      ui->lwprovice->setViewMode(QListView::IconMode);
  }
}

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