Qt 自定义分页控件的实现

#include <QWidget>

namespace Ui {
class ZPageWidget;
}

class  ZPageWidget : public QWidget
{
    Q_OBJECT

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

    /**
     * @brief setPageCount 设置总页数
     * @param count 总页数
     */
    void setPageCount(int count);
    int pageCount() const { return m_pageCount; }

    /**
     * @brief setCurrentPage 设置当前页
     * @param page 当前页码
     */
    void setCurrentPage(int page);
    int currentPage() const{ return m_currentPage; }

    /**
     * @brief setDataCount 设置数据总量
     * @param cnt 数据总量
     */
    void setDataCount(int cnt);
    int dataCount() const  { return m_dataCount; }

    /**
     * @brief setPerpageDataCount 设置每页数据量
     * @param cnt 每页数据量
     */
    void setPerpageDataCount(int cnt);
    int perpageDataCount() const  { return m_perpageDataCount; }

signals:
    /**
     * @brief sign_pageChanged 页码变化信号
     * @param page 当前页码
     */
    void sign_pageChanged(int page);

private:
    /**
     * @brief pageChanged 切换页码
     */
    void pageChanged();

private slots:
    /**
     * @brief slot_previousPageBtnClicked 前一页按钮槽函数
     */
    void slot_previousPageBtnClicked();

    /**
     * @brief slot_nextPageBtnClicked 后一页按钮槽函数
     */
    void slot_nextPageBtnClicked();
    /**
     * @brief slot_firstPageBtnClicked 首页按钮槽函数
     */
    void slot_firstPageBtnClicked();
    /**
     * @brief slot_lastPageBtnClicked 尾页按钮槽函数
     */
    void slot_lastPageBtnClicked();

    /**
     * @brief slot_skipPageBtnClicked 跳转页码按钮槽函数
     */
    void slot_skipPageBtnClicked();

private:
    Ui::ZPageWidget *ui;

    int m_pageCount;
    int m_currentPage;
    int m_dataCount;
    int m_perpageDataCount;
};

ZPageWidget::ZPageWidget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::ZPageWidget)
    , m_pageCount(1)
    , m_currentPage(1)
{
    ui->setupUi(this);

    ui->lineEdit->setValidator(new QRegExpValidator(QRegExp("[0-9]+$")));

    connect(ui->btn_previous, SIGNAL(clicked()), this, SLOT(slot_previousPageBtnClicked()));
    connect(ui->btn_next, SIGNAL(clicked()), this, SLOT(slot_nextPageBtnClicked()));
    connect(ui->btn_first, SIGNAL(clicked()), this, SLOT(slot_firstPageBtnClicked()));
    connect(ui->btn_last, SIGNAL(clicked()), this, SLOT(slot_lastPageBtnClicked()));
    connect(ui->btn_skip, SIGNAL(clicked()), this, SLOT(slot_skipPageBtnClicked()));
}

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

void ZPageWidget::setPageCount(int count)
{
    m_pageCount = count;
    m_pageCount = m_pageCount > 0 ? m_pageCount : 1;
    if(m_currentPage > m_pageCount)
    {
        m_currentPage = m_pageCount;
    }

    pageChanged();
}

void ZPageWidget::setCurrentPage(int page)
{
    m_currentPage = page;
}

void ZPageWidget::setDataCount(int cnt)
{
    m_dataCount = cnt;
    ui->lb_totalData->setText(QString("%1:%2").arg(QString::fromLocal8Bit("总数")).arg(cnt));
}

void ZPageWidget::setPerpageDataCount(int cnt)
{
    m_perpageDataCount = cnt;
    ui->lb_perPageData->setText(QString("%1:%2").arg(QString::fromLocal8Bit("每页")).arg(cnt));
}

void ZPageWidget::pageChanged()
{
    emit sign_pageChanged(m_currentPage);
    ui->lb_pageInfo->setText(QString("%1/%2").arg(m_currentPage).arg(m_pageCount));
}

void ZPageWidget::slot_previousPageBtnClicked()
{
    if(m_currentPage > 1)
    {
        m_currentPage--;
        pageChanged();
    }
}

void ZPageWidget::slot_nextPageBtnClicked()
{
    if(m_currentPage < m_pageCount)
    {
        m_currentPage++;
        pageChanged();
    }
}

void ZPageWidget::slot_firstPageBtnClicked()
{
    if(m_currentPage != 1)
    {
        m_currentPage = 1;
        pageChanged();
    }
}

void ZPageWidget::slot_lastPageBtnClicked()
{
    if(m_pageCount != m_currentPage)
    {
        m_currentPage = m_pageCount;
        pageChanged();
    }
}

void ZPageWidget::slot_skipPageBtnClicked()
{
    int page = ui->lineEdit->text().toInt();
    ui->lineEdit->clear();
    if(page > 0 && page <= m_pageCount)
    {
        m_currentPage = page;
        pageChanged();
    }
}

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

    m_dataList << QString::fromLocal8Bit("1") << QString::fromLocal8Bit("2") << QString::fromLocal8Bit("3")
               << QString::fromLocal8Bit("4") << QString::fromLocal8Bit("5") << QString::fromLocal8Bit("6")
               << QString::fromLocal8Bit("7") << QString::fromLocal8Bit("8") << QString::fromLocal8Bit("9")
               << QString::fromLocal8Bit("10") << QString::fromLocal8Bit("11") << QString::fromLocal8Bit("12")
               << QString::fromLocal8Bit("13");

    int perpageCnt = 10;
    ui->pageWidget->setPerpageDataCount(perpageCnt);
    ui->pageWidget->setDataCount(m_dataList.size());

    connect(ui->pageWidget, SIGNAL(sign_pageChanged(int)), this, SLOT(slot_pageChanged(int)));
    int pageCount = ceil(m_dataList.size() / (double)perpageCnt);
    ui->pageWidget->setPageCount(pageCount);

}

void PageControlTest::loadData()
{
    int offset = ui->pageWidget->perpageDataCount() * (ui->pageWidget->currentPage() - 1);
    QStringList currPageDataList = m_dataList.mid(offset, ui->pageWidget->perpageDataCount());

    ui->listWidget->clear();
    for (int var = 0; var < currPageDataList.size(); ++var)
    {
        ui->listWidget->addItem(currPageDataList[var]);
    }
}

void PageControlTest::slot_pageChanged(int page)
{
    loadData();
}