Qt之模型/视图（自定义按钮）

简述

衍伸前面的章节，我们对QTableView实现了数据显示、自定义排序、显示复选框、进度条等功能的实现，本节主要针对自定义按钮进行讲解，这节过后，也希望大家对自定义有更深入的了解，在以后的功能开发过程中，相信无论遇到什么样式形式，我们都可以很好地实现。

简述

效果

QStyledItemDelegate
源码

衍伸

效果

QStyledItemDelegate

源码

.h

包含显示按钮需要用到的智能指针，按钮的宽度、高度、按钮之间的间距、鼠标的坐标等。

class TableViewDelegate: public QStyledItemDelegate
{
Q_OBJECT

public:
explicit TableViewDelegate(QWidget *parent = 0);
~TableViewDelegate();
void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const;
bool editorEvent(QEvent* event, QAbstractItemModel* model, const QStyleOptionViewItem& option, const QModelIndex& index);

signals:
void open(const QModelIndex &index);
void deleteData(const QModelIndex &index);

private:
QPoint m_mousePoint;  // 鼠标位置
QScopedPointer<QPushButton> m_pOpenButton;
QScopedPointer<QPushButton> m_pDeleteButton;
QStringList m_list;
int m_nSpacing;  // 按钮之间的间距
int m_nWidth;  // 按钮宽度
int m_nHeight;  // 按钮高度
int m_nType;  // 按钮状态-1：划过 2：按下
};

.cpp

主要设置按钮样式，实现鼠标划过、按下，响应鼠标事件等操作。

TableViewDelegate::TableViewDelegate(QWidget *parent)
: QStyledItemDelegate(parent),
m_pOpenButton(new QPushButton()),
m_pDeleteButton(new QPushButton()),
m_nSpacing(5),
m_nWidth(25),
m_nHeight(20)
{
// 设置按钮正常、划过、按下样式
m_pOpenButton->setStyleSheet("QPushButton {border: none; background-color: transparent; image:url(:/Images/open);} \
QPushButton:hover {image:url(:/Images/openHover);} \
QPushButton:pressed {image:url(:/Images/openPressed);}");

m_pDeleteButton->setStyleSheet("QPushButton {border: none; background-color: transparent; image:url(:/Images/delete);} \
QPushButton:hover {image:url(:/Images/deleteHover);} \
QPushButton:pressed {image:url(:/Images/deletePressed);}");
m_list << QStringLiteral("打开") << QStringLiteral("删除");
}

TableViewDelegate::~TableViewDelegate()
{

}

// 绘制按钮
void TableViewDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
QStyleOptionViewItem viewOption(option);
initStyleOption(&viewOption, index);
if (option.state.testFlag(QStyle::State_HasFocus))
viewOption.state = viewOption.state ^ QStyle::State_HasFocus;

QStyledItemDelegate::paint(painter, viewOption, index);

if (index.column() == FILE_OPERATE_COLUMN)
{
// 计算按钮显示区域
int nCount = m_list.count();
int nHalf = (option.rect.width() - m_nWidth * nCount - m_nSpacing * (nCount - 1)) / 2;
int nTop = (option.rect.height() - m_nHeight) / 2;

for (int i = 0; i < nCount; ++i)
{
// 绘制按钮
QStyleOptionButton button;
button.rect = QRect(option.rect.left() + nHalf + m_nWidth * i + m_nSpacing * i,
option.rect.top() + nTop,  m_nWidth, m_nHeight);
button.state |= QStyle::State_Enabled;
//button.iconSize = QSize(16, 16);
//button.icon = QIcon(QString(":/Images/%1").arg(m_list.at(i)));

if (button.rect.contains(m_mousePoint))
{
if (m_nType == 0)
{
button.state |= QStyle::State_MouseOver;
//button.icon = QIcon(QString(":/Images/%1Hover").arg(m_list.at(i)));
}
else if (m_nType == 1)
{
button.state |= QStyle::State_Sunken;
//button.icon = QIcon(QString(":/Images/%1Pressed").arg(m_list.at(i)));
}
}

QWidget *pWidget = (i == 0) ? m_pOpenButton.data() : m_pDeleteButton.data();
QApplication::style()->drawControl(QStyle::CE_PushButton, &button, painter, pWidget);
}
}
}

// 响应按钮事件 - 划过、按下
bool TableViewDelegate::editorEvent(QEvent* event, QAbstractItemModel* model, const QStyleOptionViewItem& option, const QModelIndex& index)
{
if (index.column() != FILE_OPERATE_COLUMN)
return false;

m_nType = -1;
bool bRepaint = false;
QMouseEvent *pEvent = static_cast<QMouseEvent *> (event);
m_mousePoint = pEvent->pos();

int nCount = m_list.count();
int nHalf = (option.rect.width() - m_nWidth * nCount - m_nSpacing * (nCount - 1)) / 2;
int nTop = (option.rect.height() - m_nHeight) / 2;

// 还原鼠标样式
QApplication::restoreOverrideCursor();

for (int i = 0; i < nCount; ++i)
{
QStyleOptionButton button;
button.rect = QRect(option.rect.left() + nHalf + m_nWidth * i + m_nSpacing * i,
option.rect.top() + nTop,  m_nWidth, m_nHeight);

// 鼠标位于按钮之上
if (!button.rect.contains(m_mousePoint))
continue;

bRepaint = true;
switch (event->type())
{
// 鼠标滑过
case QEvent::MouseMove:
{
// 设置鼠标样式为手型
QApplication::setOverrideCursor(Qt::PointingHandCursor);

m_nType = 0;
QToolTip::showText(pEvent->globalPos(), m_list.at(i));
break;
}
// 鼠标按下
case QEvent::MouseButtonPress:
{
m_nType = 1;
break;
}
// 鼠标释放
case QEvent::MouseButtonRelease:
{
if (i == 0)
{
emit open(index);
}
else
{
emit deleteData(index);
}
break;
}
default:
break;
}
}

return bRepaint;
}

衍伸

通过上面的实现，我们可以自定义按钮的样式、文本、显示区域、等，我们也可以通过QStyleOptionButton的icon和iconSize来设置按钮的图标与图标大小，通过响应按钮来实现我们自己的事件。