QListWidget、QMenu、Action、customContextMenuRequested

QListWidget的初始化、清空、Append添加、Insert添加、删除item

QListWidget的事件的使用

QToolBox的使用，每个Page可以添加其他控件

QToolBar使用代码添加QMenu,QMenu添加3个Action

QToolButton绑定Action

布局

其中 QSplitter比较特殊，允许在水平或垂直方向上分割窗口中的多个子部件或控件。

添加方法，选中ToolBox和groupbox两个控件后，右键布局→在水平方向上分割

.h

cpp 复制代码

#ifndef LISTWIDGETEXAMPLE_H
#define LISTWIDGETEXAMPLE_H

#include <QMainWindow>
#include <QListWidgetItem>

namespace Ui {
class ListWidgetExample;
}

class ListWidgetExample : public QMainWindow
{
    Q_OBJECT

private:
    void setActionsForButton();//为工具button关联到action
    void createSelectionMenu();//创建下拉菜单
    void setItem(QListWidgetItem *item, bool editEnable);//设置一个item
    QIcon getIcon();

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

private slots:
    void on_actListClear_triggered();

    void on_actListIni_triggered();

    void on_chkBoxListEditable_clicked(bool checked);

    void on_actListAppend_triggered();

    void on_actListDelete_triggered();

    void on_actListInsert_triggered();

    void on_actSelectAll_triggered();

    void on_actSelectNone_triggered();

    void on_actSelectInvert_triggered();

    void on_btnAsc_clicked();

    void on_btnDec_clicked();

    void on_chkAllowSort_clicked(bool checked);

    void on_listWidget_currentRowChanged(int currentRow);

    void on_listWidget_currentTextChanged(const QString &currentText);

    void on_listWidget_itemChanged(QListWidgetItem *item);

    void on_listWidget_itemEntered(QListWidgetItem *item);

    void on_listWidget_itemPressed(QListWidgetItem *item);

    void on_listWidget_itemDoubleClicked(QListWidgetItem *item);

    void on_btnClearText_clicked();

    void on_btnAddEmptyRow_clicked();

    void on_listWidget_currentItemChanged(QListWidgetItem *current, QListWidgetItem *previous);

    void on_listWidget_customContextMenuRequested(const QPoint &pos);

private:
    Ui::ListWidgetExample *ui;
};

#endif // LISTWIDGETEXAMPLE_H

.cpp

cpp 复制代码

#include "listwidgetexample.h"
#include "ui_listwidgetexample.h"



//将 toolButton 关联到 相应的action
void ListWidgetExample::setActionsForButton()
{
    ui->tBtnListIni->setDefaultAction(ui->actListIni);
    ui->tBtnListClear->setDefaultAction(ui->actListClear);
    ui->tBtnListAppend->setDefaultAction(ui->actListAppend);
    ui->tBtnListInsert->setDefaultAction(ui->actListInsert);
    ui->tBtnListDelete->setDefaultAction(ui->actListDelete);

    ui->tBtnSelAll->setDefaultAction(ui->actSelectAll);
    ui->tBtnSelNone->setDefaultAction(ui->actSelectNone);
    ui->tBtnSelnvert->setDefaultAction(ui->actSelectInvert);
}
//在toolBar中创建一个下拉菜单
void ListWidgetExample::createSelectionMenu()
{
    //创建下拉菜单 加入全选、空选、反选
    QMenu *menuSelection = new QMenu(this);
    menuSelection->addAction(ui->actSelectAll);
    menuSelection->addAction(ui->actSelectNone);
    menuSelection->addAction(ui->actSelectInvert);

    //在listWidget的tBtnSelection 关联menu 关联action
    ui->tBtnSelectItem->setPopupMode(QToolButton::MenuButtonPopup);
    // ui->tBtnSelectItem->setToolButtonStyle(Qt::ToolButtonTextBesideIcon);
    ui->tBtnSelectItem->setDefaultAction(ui->actSelPopMenu);
    ui->tBtnSelectItem->setMenu(menuSelection);

    //工具栏 toolBar新建一个ToolBatton 然后关联menu 关联action
    QToolButton *btn = new QToolButton(this);
    btn->setPopupMode(QToolButton::InstantPopup);
    btn->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    btn->setMenu(menuSelection);
    btn->setText("选择");
    QIcon icon;
    icon.addFile("://images/icon.bmp");
    btn->setIcon(icon);
    ui->toolBar->addWidget(btn);

    //最后在工具栏toolBar增加一个分隔符，然后加入退出
    ui->toolBar->addSeparator();
    ui->toolBar->addAction(ui->actQuit);

}

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

    setCentralWidget(ui->splitter); //设置中心组件
    ui->listWidget->setContextMenuPolicy(Qt::CustomContextMenu);//不设置这句，无法弹出自定义菜单
    this->setActionsForButton();
    this->createSelectionMenu();
}

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

void ListWidgetExample::on_actListClear_triggered()
{
    ui->listWidget->clear();
}
//设置item的flag属性
void ListWidgetExample::setItem(QListWidgetItem *item, bool editEnable)
{
    if(editEnable)
        item->setFlags(Qt::ItemIsSelectable
                       |Qt::ItemIsEnabled
                       |Qt::ItemIsUserCheckable
                       |Qt::ItemIsEditable);
    else
        item->setFlags(Qt::ItemIsSelectable
                       |Qt::ItemIsEnabled
                       |Qt::ItemIsUserCheckable);
}


//初始化列表数据
void ListWidgetExample::on_actListIni_triggered()
{
    ui->listWidget->clear();
    bool chk= ui->chkBoxListEditable->isChecked();
    QIcon icon;
    icon.addFile(":/toolbar/toolbarimages/724.bmp");

    QListWidgetItem *item ;
    for(int i=0;i<10;i++)
    {
        QString str=QString("Item %1").arg(i);
        item= new QListWidgetItem();
        item->setText(str);
        item->setIcon(icon);
        item->setCheckState(Qt::Checked);
        this->setItem(item,chk);

        ui->listWidget->addItem(item);
    }
}


//点击勾选框，遍历listWidget里面的item，设置 是否可编辑。
void ListWidgetExample::on_chkBoxListEditable_clicked(bool checked)
{
    int count = ui->listWidget->count();
    QListWidgetItem *item;
    for(int i=0;i<count;i++)
    {
        item = ui->listWidget->item(i);
        this->setItem(item,checked);
    }
}

QIcon ListWidgetExample::getIcon()
{
    QIcon icon;
    icon.addFile(":/toolbar/toolbarimages/724.bmp");
    return icon;
}


void ListWidgetExample::on_actListAppend_triggered()
{
    QListWidgetItem *item = new QListWidgetItem("Added Item");
    item->setIcon(this->getIcon());
    item->setCheckState(Qt::Checked);
    this->setItem(item,ui->chkBoxListEditable->isChecked());
    ui->listWidget->addItem(item);
}

void ListWidgetExample::on_actListInsert_triggered()
{
    QListWidgetItem *item = new QListWidgetItem("Inserted Item");
    item->setIcon(this->getIcon());
    item->setCheckState(Qt::Checked);
    this->setItem(item,ui->chkBoxListEditable->isChecked());
    ui->listWidget->insertItem(ui->listWidget->currentRow(),item);
}


void ListWidgetExample::on_actListDelete_triggered()
{
    int row = ui->listWidget->currentRow();
    QListWidgetItem *item = ui->listWidget->takeItem(row);
    delete item;//需要手工删除对象
}







void ListWidgetExample::on_actSelectAll_triggered()
{
    for(int i=0;i<ui->listWidget->count();i++)
    {
        QListWidgetItem *item = ui->listWidget->item(i);
        item->setCheckState(Qt::Checked);//设置为选中
    }
}


void ListWidgetExample::on_actSelectNone_triggered()
{
    for(int i=0;i<ui->listWidget->count();i++)
    {
        QListWidgetItem *item = ui->listWidget->item(i);
        item->setCheckState(Qt::Unchecked);//设置为不选中
    }
}


//反选
void ListWidgetExample::on_actSelectInvert_triggered()
{
    for(int i=0;i<ui->listWidget->count();i++)
    {
        QListWidgetItem *item = ui->listWidget->item(i);
        if(item->checkState()!= Qt::Checked)
            item->setCheckState(Qt::Checked);
        else
            item->setCheckState(Qt::Unchecked);//设置为不选中
    }
}






void ListWidgetExample::on_btnAsc_clicked()
{
    ui->listWidget->sortItems(Qt::AscendingOrder);
}



void ListWidgetExample::on_btnDec_clicked()
{
    ui->listWidget->sortItems(Qt::DescendingOrder);
}



void ListWidgetExample::on_chkAllowSort_clicked(bool checked)
{
    ui->listWidget->setSortingEnabled(checked);
}


void ListWidgetExample::on_listWidget_currentRowChanged(int currentRow)
{
    ui->plainTextEdit->appendPlainText(
        QString("currentRowChanged,currentRow=%1").arg(currentRow)
        );
}




void ListWidgetExample::on_listWidget_currentTextChanged(const QString &currentText)
{
    ui->plainTextEdit->appendPlainText(
        QString("currentTextChanged,currentText=%1").arg(currentText)
        );
}

void ListWidgetExample::on_listWidget_itemChanged(QListWidgetItem *item)
{
    ui->plainTextEdit->appendPlainText(
        QString("itemChanged,itemText=%1").arg(item->text())
        );
}


void ListWidgetExample::on_listWidget_itemEntered(QListWidgetItem *item)
{
    ui->plainTextEdit->appendPlainText(
        QString("itemEntered,itemText=%1").arg(item->text())
        );
}


void ListWidgetExample::on_listWidget_itemPressed(QListWidgetItem *item)
{
    ui->plainTextEdit->appendPlainText(
        QString("itemPressed,itemText=%1").arg(item->text())
        );
}


void ListWidgetExample::on_listWidget_itemDoubleClicked(QListWidgetItem *item)
{
    ui->plainTextEdit->appendPlainText(
        QString("itemDoubleClicked,itemText=%1").arg(item->text())
        );
}


void ListWidgetExample::on_btnClearText_clicked()
{
    ui->plainTextEdit->clear();
}


void ListWidgetExample::on_btnAddEmptyRow_clicked()
{
    ui->plainTextEdit->appendPlainText("");
}


void ListWidgetExample::on_listWidget_currentItemChanged(QListWidgetItem *current, QListWidgetItem *previous)
{
    QString str;
    if(current!=NULL)
    {
        if(previous!=NULL)
        {
            str=QString("前项：%1 当前：%2").arg(previous->text()).arg(current->text());
        }
        else
            str=QString("当前：%2").arg(current->text());
        ui->editCutItemText->setText(str);
    }
    ui->plainTextEdit->appendPlainText(QString("currentItemChanged触发"));
}

//自定义右键
void ListWidgetExample::on_listWidget_customContextMenuRequested(const QPoint &pos)
{
    ui->plainTextEdit->appendPlainText("customContextMenuRequested---开始");
    Q_UNUSED(pos);
    QMenu *menu= new QMenu(this);

    menu->addAction(ui->actListIni);
    menu->addAction(ui->actListClear);
    menu->addAction(ui->actListAppend);
    menu->addAction(ui->actListDelete);
    menu->addAction(ui->actListInsert);

    menu->addSeparator();

    menu->addAction(ui->actSelectAll);
    menu->addAction(ui->actSelectNone);
    menu->addAction(ui->actSelectInvert);

    menu->exec(QCursor::pos());//在光标处显示快捷菜单
    delete menu;  //菜单显示完，需要删除对象
    ui->plainTextEdit->appendPlainText("customContextMenuRequested---结束");

}

效果

疑问

setSortingEnabled之后，仍然可以ui->listWidget->sortItems(Qt::AscendingOrder);

后面再看什么问题