QCombobox下拉選擇線寬

效果圖

代碼

h檔案
           

#ifndef CLINEWIDTH_H
#define CLINEWIDTH_H

#include <QObject>
#include <QLabel>
#include <QComboBox>
#include <QListWidget>
#include <QLineEdit>

enum EmLabelType{emItem = 0, emLineEdit};//label類型,0:下拉框的item，1:combobox的編輯框
class CLineWidthItem : public QLabel
{
    Q_OBJECT
public:
    CLineWidthItem( EmLabelType type = emItem,int width = 0,QWidget *parent = nullptr);
    ~CLineWidthItem() override;
    void setWidth(const int & width);
protected:
    void paintEvent(QPaintEvent *) override;
    void mousePressEvent(QMouseEvent *event) override;
private:
    int m_width;//線條寬度
    EmLabelType m_type;//label類型
signals:
    void click(const int & width);
    void sigMouseMove();
};
class QShowLineInEdit : public QLineEdit
{
Q_OBJECT
public:
    QShowLineInEdit(const int & width = 0,QWidget *parent = nullptr);
    ~QShowLineInEdit()override;
    void setWidth(const int & width);
private:
    CLineWidthItem * m_pLabel;
    int m_width;//線條寬度
};
class CLineWidthBox :public QComboBox
{
    Q_OBJECT
public:
    CLineWidthBox(QWidget *parent = Q_NULLPTR);
    ~CLineWidthBox()override;

    int GetCurrentIndex();
    void SetCurrentIndex(int idx);
private slots:
    void onClickPenWidget(const int& index);
public:
    void appendItem(const int& index);
private:
    QListWidget* m_pListWidget;
    int m_index;
    QShowLineInEdit *m_pShowLineInEdit;
};
#endif // CPENCSSEDITOR_H

           

cpp檔案
           

#include "clinewidth.h"
#include <QPainter>
#include <QHBoxLayout>

//-- class_1 下拉框中的item
CLineWidthItem::CLineWidthItem(EmLabelType type,int width,QWidget *parent)
    :QLabel(parent)
    , m_width(width)
    ,m_type(type)
{

}

CLineWidthItem::~CLineWidthItem()
{
}

void CLineWidthItem::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);

    QSize size = this->size();
    QPainter painter(this);
    QPen pen;
    pen.setColor(Qt::black);
    pen.setWidth(m_width+1);
    painter.setPen(pen);

    QPoint p1(0, size.height() / 2);
    QPoint p2(size.width(), size.height() / 2);
    QLine line(p1, p2);
    painter.drawLine(line);
}

void CLineWidthItem::mousePressEvent(QMouseEvent *event)
{
    if(m_type == emItem)
    {
        click(m_width);
    }
    QLabel::mousePressEvent(event);
}

void CLineWidthItem::setWidth(const int &width)
{
    m_width = width;
}

//-- class_2 combobox中的顯示的編輯框
QShowLineInEdit::QShowLineInEdit(const int & width,QWidget *parent)
    :QLineEdit(parent)
    ,m_width(width)
{
    m_pLabel = new CLineWidthItem(emLineEdit,width,this);

    QHBoxLayout* layout = new QHBoxLayout();
    layout->addWidget(m_pLabel);
    layout->setMargin(0);
    setLayout(layout);
    setReadOnly(true);
}


QShowLineInEdit::~QShowLineInEdit()
{

}

void QShowLineInEdit::setWidth(const int &width)
{
    m_pLabel->setWidth(width);
}

//-- class_3 能選擇線寬的combobox
CLineWidthBox::CLineWidthBox(QWidget *parent)
    :QComboBox(parent)
{
    m_index = 0;
    m_pListWidget = new QListWidget();
    //setContextMenuPolicy(Qt::NoContextMenu);//禁用菜單
    //m_pListWidget->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);//禁用垂直滾動條
    m_pListWidget->setStyleSheet("QListWidget::Item:hover{background-color:rgb(0,125,255);}");
    setModel(m_pListWidget->model());
    setView(m_pListWidget);

    m_pShowLineInEdit = new QShowLineInEdit(0,this);
    setLineEdit(m_pShowLineInEdit);
    SetCurrentIndex(0);
}

CLineWidthBox::~CLineWidthBox()
{

}

void CLineWidthBox::appendItem(const int& index)
{
    CLineWidthItem* pWid = new CLineWidthItem(emItem,index,this);
    connect(pWid, SIGNAL(click(const int&)), this, SLOT(onClickPenWidget(const int& )));
    QListWidgetItem* pItem = new QListWidgetItem(m_pListWidget);

    m_pListWidget->addItem(pItem);
    m_pListWidget->setItemWidget(pItem, pWid);

}

void CLineWidthBox::onClickPenWidget(const int& index)
{
    m_index = index;
    m_pShowLineInEdit->setWidth(index);
    setCurrentIndex(index-1);
    hidePopup();
}

int CLineWidthBox::GetCurrentIndex()
{
    return m_index;
}

void CLineWidthBox::SetCurrentIndex(int index)
{
    m_index = index;
}


           

應用
           

ui->comboBox_3->appendItem(0);//注意：comboBox_3必須提升為CLineWidthBox
ui->comboBox_3->appendItem(1);
ui->comboBox_3->appendItem(2);
ui->comboBox_3->appendItem(3);
ui->comboBox_3->appendItem(4);