Qt学习: QListWidget程序示例

学习了上一条博客的关于QListWidget的成员函数的用法，下面就有一个相关的简单小程序来练下手:
程序完成如下图:

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第一步，我们先通过ui设计师拖拽出我们想要的布局:

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下面是”c.cpp”下的代码:我将逐句讲解:

#include "c.h"c::c(QWidget *parent)    : QMainWindow(parent){    //应用ui设计师布局.    ui.setupUi(this);    //把两个按钮设置为选中.    ui.listButton->setChecked(true);    ui.upButton->setChecked(true);    //列表部件采用排序.默认采用AAA-ZZZ排序.    ui.listWidget->setSortingEnabled(true);    //往列表部件中加入项组.一共3个.    ui.listWidget->addItems(QStringList()<<QString::fromLocal8Bit("北京")<<QString::fromLocal8Bit("上海")<<QString::fromLocal8Bit("杭州"));    //设置标题为"QListWidget".    this->setWindowTitle(QString::fromLocal8Bit("QListWidget"));    //对于前面的三个项设置图标.可根据实际情况使用.    ui.listWidget->item(0)->setIcon(QIcon("Icons/1.jpg"));    ui.listWidget->item(1)->setIcon(QIcon("Icons/2.jpg"));     ui.listWidget->item(2)->setIcon(QIcon("Icons/3.png"));    //设置项的选择情况.    ui.listWidget->setSelectionMode(QAbstractItemView::ExtendedSelection);    //连接信号与槽.    connect(ui.addButton, SIGNAL(clicked()), this, SLOT(addItemSlot()));    connect(ui.delButton, SIGNAL(clicked()), this, SLOT(delItemSlot()));    connect(ui.delAllButton, SIGNAL(clicked()), this, SLOT(delAllItemSlot()));    //QLineEdit的信号:void returnPressed()的意思是:当焦点在lineEdit内时，敲击enter键，发出信号.    connect(ui.lineEdit, SIGNAL(returnPressed()), this, SLOT(addItemSlot()));    connect(ui.listButton, SIGNAL(clicked()), this, SLOT(changeListWidgetViewModeSlot()));    connect(ui.iconButton, SIGNAL(clicked()), this, SLOT(changeListWidgetViewModeSlot()));    connect(ui.upButton, SIGNAL(clicked()), this, SLOT(changeSortModeSlot()));    connect(ui.downButton, SIGNAL(clicked()), this, SLOT(changeSortModeSlot()));}c::~c(){}void c::addItemSlot(){    //创建一个QListWidget的项.    QListWidgetItem *ite = new QListWidgetItem;    //从lineEdit行编辑框中获取输入的文字.    QString iteText = ui.lineEdit->text();    //一定要检查是否空，否则也会输入进去!!!    if (iteText.isEmpty())        return;    //然后设置项的文本.    ite->setText(iteText);    //最后把这个项加入到列表部件中去.    ui.listWidget->addItem(ite);    //清空行编辑器，坐下善后工作.    ui.lineEdit->clear();}void c::delItemSlot(){    //直接使用QListWidget部件的删除函数，通过currentItem()成员函数来获取当前的选择项.    ui.listWidget->removeItemWidget(ui.listWidget->currentItem());}void c::delAllItemSlot(){    /*//通过循环一个个删除QListWidget内的项.    int count = ui.listWidget->count();    for (int i = count - 1; i >= 0; --i)    {        QListWidgetItem* ite = ui.listWidget->takeItem(i);        if (ite != 0)            delete ite;    }*/    //也可以直接:    ui.listWidget->clear();}void c::changeListWidgetViewModeSlot(){    //判断对于列表显示模式的选择情况.如果选择了列表模式，则设置列表模式.    if (ui.listButton->isChecked())    {        ui.listWidget->setViewMode(QListView::ListMode);    }    //否则选择图标模式.    else    {        ui.listWidget->setViewMode(QListView::IconMode);    }}void c::changeSortModeSlot(){    //判断循环模式的选择情况.    if (ui.upButton->isChecked())    {        ui.listWidget->sortItems(Qt::AscendingOrder);    }    else    {        ui.listWidget->sortItems(Qt::DescendingOrder);    }}

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最后贴下”c.h”下的代码:

#ifndef C_H#define C_H#include <QtWidgets/QMainWindow>#include "ui_c.h"#include <QListWidget>#include <QListWidgetItem>#include <QMessageBox>class c : public QMainWindow{    Q_OBJECTpublic:    c(QWidget *parent = 0);    ~c();private slots:    void addItemSlot();    void delItemSlot();    void delAllItemSlot();    void changeListWidgetViewModeSlot();    void changeSortModeSlot();private:    Ui::cClass ui;};#endif // C_H

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main.cpp下的代码:

#include "c.h"#include <QtWidgets/QApplication>int main(int argc, char *argv[]){    QApplication a(argc, argv);    c w;    w.show();    return a.exec();}