（14）本源代码定义于头文件 qtablewidget . h 头文件 ：

#ifndef QTABLEWIDGET_H
#define QTABLEWIDGET_H#include <QtWidgets/qtableview.h>
#include <QtWidgets/qtwidgetsglobal.h>
#include <QtCore/qlist.h>
#include <QtCore/qvariant.h>QT_REQUIRE_CONFIG(tablewidget);QT_BEGIN_NAMESPACEclass QTableWidgetSelectionRange
{
public:QTableWidgetSelectionRange() = default;QTableWidgetSelectionRange(int top, int left, int bottom, int right): m_top(top), m_left(left), m_bottom(bottom), m_right(right){}inline int topRow() const { return m_top; }inline int bottomRow() const { return m_bottom; }inline int leftColumn() const { return m_left; }inline int rightColumn() const { return m_right; }inline int rowCount() const { return m_bottom - m_top + 1; }inline int columnCount() const { return m_right - m_left + 1; }
private:int m_top = -1, m_left = -1, m_bottom = -2, m_right = -2;
};class QTableWidget;
class QTableModel;
class QWidgetItemData;
class QTableWidgetItemPrivate;/*
The QTableWidgetItem class provides an item for use with the QTableWidget class.Detailed Description ：
表格项用于存储表格小部件的信息。项目通常包含文本、图标或复选框。
QTableWidgetltem类是一个方便的类，它在Qt 3中替换了QTableWidgetltem类。
它提供了一个可以与QTableWidgetltem类一起使用的项目。
顶级项目在没有父项的情况下构建，然后根据行号和列号指定的位置插入:QTableWidgetItem * newItem = new QTableWidgetItem(tr("%1").arg(pow(row, column+1)));tableWidget->setItem(row, column, newItem);每个项目都可以有自己的背景画笔，这通过`setBackground()、函数来设置。
当前的背景画笔可以通过background ()、函数来获取。
每个项目的文本标签可以使用其特定的字体和画笔来呈现，这通过`setFont ()'和setForeground)函数进行指定，
并通过`font()`和`foreground()'函数来读取。默认情况下，项是启用的，可编辑的，可选择的，可检查的，并且既可以作为拖放操作的源，也可以作为落点目标。
每个项的标记可以通过调用setFlags()函数并传入相应的值(见Qt:ItemFlags)来更改。
可检查的项可以通过setCheckState()函数进行检查和取消检查。
对应的checkState()函数则指示该项当前是否被检查过。Subclassing :
当子类化 QTableWidgetltem 以提供自定义项时，可以为它们定义新类型，以便它们可以与标准项区分开来.
需要此功能的子类的构造函数需要使用等于或大于 UserType 的新类型值调用基类构造函数。*/class Q_WIDGETS_EXPORT QTableWidgetItem
{friend class QTableWidget;friend class QTableModel;
private:QTableModel * tableModel() const;private: //可见，表格里的条目还有丰富的数据成员，以描述条目里的数据与属性int                       rtti     ;QList<QWidgetItemData>    values   ; //包含了条目里的数据QTableWidget            * view     ; //本条目属于哪个表格窗体。QTableWidgetItemPrivate * d        ;Qt::ItemFlags             itemFlags; //本条目的编辑属性。public:enum ItemType { Type = 0, UserType = 1000 };//Constructs a table item of the specified type that does not belong to any table.//形参 type会赋值给本类的私有数据成员 rtti，以保存本条目的类型。explicit   QTableWidgetItem(int type = Type); //默认类型是 0inline int type() const { return rtti; }//Returns the type passed to the QTableWidgetItem constructor.//Constructs a table item with the given text.explicit   QTableWidgetItem(const QString & text, int type = Type); //有参构造函数explicit   QTableWidgetItem(const QIcon   & icon,const QString & text, int type = Type);QTableWidgetItem(const QTableWidgetItem & other); //copy构造函数QTableWidgetItem & operator=(const QTableWidgetItem & other);//copy赋值运算符函数virtual ~QTableWidgetItem(); //析构函数virtual bool operator< (const QTableWidgetItem & other) const; //无注释virtual QTableWidgetItem * clone() const; //Creates a copy of the item.//Returns the table widget that contains the item.inline  QTableWidget     * tableWidget() const { return view; }inline int row   () const{   return (view ? view->row(this)    : -1); }inline int column() const{   return (view ? view->column(this) : -1); }//Returns the row of the item in the table.//If the item is not in a table, this function will return -1.virtual void read (QDataStream & in )      ; //Reads  the item from stream in .virtual void write(QDataStream & out) const; //Writes the item to   stream out.//Returns true if the item is selected, otherwise returns false.bool  isSelected() const;void setSelected(bool select); //Sets the selected state of the item to select./*enum Qt::ItemFlag {NoItemFlags = 0,ItemIsSelectable = 1,ItemIsEditable = 2,ItemIsDragEnabled = 4,ItemIsDropEnabled = 8,ItemIsUserCheckable = 16,ItemIsEnabled = 32,ItemIsAutoTristate = 64,ItemNeverHasChildren = 128,ItemIsUserTristate = 256};Q_DECLARE_FLAGS(ItemFlags, ItemFlag)Q_DECLARE_OPERATORS_FOR_FLAGS(ItemFlags)*/inlineQt::ItemFlags        flags() const { return itemFlags; } //返回条目具有的属性void              setFlags(Qt::ItemFlags flags);virtual QVariant     data(int role) const;               //读写条目里具有的数据。virtual void      setData(int role, const QVariant &value);//以下依次是读写条目里各角色对应的数据。inline QString       text() const         //角色 0{   return data(Qt::DisplayRole).toString(); }inline void       setText(const QString & text){   setData(Qt::DisplayRole, text); }inline QIcon         icon() const         //角色 1{   return qvariant_cast<QIcon>(data(Qt::DecorationRole)); }inline void       setIcon(const QIcon & icon){   setData(Qt::DecorationRole, icon); }inline QString       toolTip() const      //角色 3{ return data(Qt::ToolTipRole).toString(); }inline void       setToolTip(const QString & toolTip){ setData(Qt::ToolTipRole, toolTip); }inline QString       statusTip() const    //角色 4{   return data(Qt::StatusTipRole).toString(); }inline void       setStatusTip(const QString &statusTip){   setData(Qt::StatusTipRole, statusTip); }inline QString       whatsThis() const    //角色 5{   return data(Qt::WhatsThisRole).toString(); }inline void       setWhatsThis(const QString & whatsThis){   setData(Qt::WhatsThisRole, whatsThis); }inline QFont         font() const         //角色 6{   return qvariant_cast<QFont>(data(Qt::FontRole)); }inline void       setFont(const QFont & font){   setData(Qt::FontRole, font); }inline int           textAlignment() const//角色 7{   return data(Qt::TextAlignmentRole).toInt(); }inline void       setTextAlignment(int alignment){   setData(Qt::TextAlignmentRole, alignment); }inline QBrush        background() const   //角色 8{   return qvariant_cast<QBrush>(data(Qt::BackgroundRole)); }inline void       setBackground(const QBrush & brush){   setData(Qt::BackgroundRole,brush.style() != Qt::NoBrush ? QVariant(brush) : QVariant()); }//QBrush(Qt::GlobalColor color, Qt::BrushStyle bs = Qt::SolidPattern);inline QBrush        foreground() const   //角色 9{   return qvariant_cast<QBrush>(data(Qt::ForegroundRole)); }inline void       setForeground(const QBrush &brush){   setData(Qt::ForegroundRole,brush.style() != Qt::NoBrush ? QVariant(brush) : QVariant()); }inline  //enum Qt::CheckState { Unchecked, PartiallyChecked, Checked };Qt::CheckState       checkState() const   //角色 10{   return static_cast<Qt::CheckState>(data(Qt::CheckStateRole).toInt()); }inlinevoid              setCheckState(Qt::CheckState state){   setData(Qt::CheckStateRole, state); }inline QSize         sizeHint() const     //角色 13{   return qvariant_cast<QSize>(data(Qt::SizeHintRole)); }inline void       setSizeHint(const QSize & size){   setData(Qt::SizeHintRole, size.isValid() ? QVariant(size) : QVariant()); }}; //完结 class QTableWidgetItem#ifndef QT_NO_DATASTREAMQ_WIDGETS_EXPORT QDataStream & operator>>(QDataStream &in , QTableWidgetItem       &item);
Q_WIDGETS_EXPORT QDataStream & operator<<(QDataStream &out, const QTableWidgetItem &item);#endifclass QTableWidgetPrivate;/*
The QTableWidget class provides an item-based table view with a default model.Detailed Description :
表格小部件为应用程序提供标准的表格显示功能。QTableWidgetltem中的项目由 QTableWidgetltem 提供。如果你想使用自己的数据模型来创建表格，你应该使用QTableView而不是这个类。表格小部件可以使用所需数量的行和列进行构建:tableWidget = new QTableWidget(12, 3, this);Alternatively, tables can be constructed without a given size and resized later:tableWidget = new QTableWidget(this);tableWidget->setRowCount(10);tableWidget->setColumnCount(5);项目在表之外创建(没有父控件)并使用设置方法插入到表中。QTableWidgetItem * newItem = new QTableWidgetItem(tr("%1").arg((row+1)*(column+1)));tableWidget->setItem(row, column, newItem);如果您想在表格控件中启用排序功能，详细信息，请参阅setltem()方法.
请在填充内容后执行此操作，否则排序可能会影响插入顺序.表格可以同时拥有横向和纵向标题。创建标题的最简单方法是向`setHorizontalHeaderLabels()和
`setVerticalHeaderLabels('函数提供一系列字符串。
这些函数将为表格的列和行提供简单的文本标题。
更复杂的标题可以由现有的表格项生成，而这些表格项通常是在表格之外构建的。
例如，我们可以构建一个带有图标和对齐文本的表格项，并将其用作特定列的标题:QTableWidgetItem *cubesHeaderItem = new QTableWidgetItem(tr("Cubes"));cubesHeaderItem->setIcon(QIcon(QPixmap(":/Images/cubed.png")));cubesHeaderItem->setTextAlignment(Qt::AlignVCenter);The number of rows in the table can be found with rowCount(),
and the number of columns with columnCount().
The table can be cleared with the clear() function.
表格中的行数可以通过rowCount()找到，列数通过columncount()找到。
表格可以通过clear()函数清空。*/class Q_WIDGETS_EXPORT QTableWidget : public QTableView
{Q_OBJECT//This property holds the number of columns / rows in the table.//By default, for a table constructed without row and column counts,//  this property contains a value of 0.Q_PROPERTY(int    rowCount READ    rowCount WRITE    setRowCount)Q_PROPERTY(int columnCount READ columnCount WRITE setColumnCount)friend class QTableModel; //这是 Qt3 里的老类，已被模型视图架构替代了。注释文档里这么说的。private:void setModel(QAbstractItemModel * model) override; //私有，不再被调用了。Q_DECLARE_PRIVATE(QTableWidget)Q_DISABLE_COPY(QTableWidget)Q_PRIVATE_SLOT(d_func(), void _q_sort())Q_PRIVATE_SLOT(d_func(), void _q_emitItemEntered       (const QModelIndex & index))Q_PRIVATE_SLOT(d_func(), void _q_emitItemPressed       (const QModelIndex & index))Q_PRIVATE_SLOT(d_func(), void _q_emitItemClicked       (const QModelIndex & index))Q_PRIVATE_SLOT(d_func(), void _q_emitItemDoubleClicked (const QModelIndex & index))Q_PRIVATE_SLOT(d_func(), void _q_emitItemActivated     (const QModelIndex & index))Q_PRIVATE_SLOT(d_func(), void _q_emitItemChanged       (const QModelIndex & index))Q_PRIVATE_SLOT(d_func(), void _q_emitCurrentItemChanged(const QModelIndex & previous,const QModelIndex & current))Q_PRIVATE_SLOT(d_func(), void _q_dataChanged           (const QModelIndex & topLeft,const QModelIndex & bottomRight))public://Creates a new table view with the given parent.explicitQTableWidget(                       QWidget * parent = nullptr);  //有参构造函数QTableWidget(int rows, int columns, QWidget * parent = nullptr); //有参构造函数//Creates a new table view with the given rows and columns, and with the given parent.~QTableWidget();  //析构函数//Q_PROPERTY(int    rowCount    READ    rowCount    WRITE    setRowCount)int             rowCount() const;void         setRowCount(int rows);//Q_PROPERTY(int    columnCount READ    columnCount WRITE    setColumnCount)int             columnCount() const;void         setColumnCount(int columns);/*  这是表格窗体视图的基类表格视图里的构建表头的代码方法。
class QTableView : public QAbstractItemView
{
public :QHeaderView *     horizontalHeader() const;void           setHorizontalHeader(QHeaderView * header);QHeaderView *     verticalHeader  () const;void           setVerticalHeader  (QHeaderView * header);
}
*///Returns the horizontal header item for column, column, if one has been set;//  otherwise returns nullptr.QTableWidgetItem *      horizontalHeaderItem(int column) const;void                 setHorizontalHeaderItem(int column, QTableWidgetItem * item);//Sets the horizontal header item for column column to item.//If necessary, the column count is increased to fit the item.//The previous header item (if there was one) is deleted.之前的旧标题元素会被删除。QTableWidgetItem *  takeHorizontalHeaderItem(int column);//Removes the horizontal header item at column from the header without deleting it.QTableWidgetItem *        verticalHeaderItem(int row) const;void                   setVerticalHeaderItem(int row, QTableWidgetItem * item);QTableWidgetItem *    takeVerticalHeaderItem(int row);//Sets the vertical header labels using labels.void                   setVerticalHeaderLabels(const QStringList & labels);void                 setHorizontalHeaderLabels(const QStringList & labels);//Returns the item for the given row and column if one has been set;//  otherwise returns nullptr.QTableWidgetItem *        item(int row, int column) const;void                   setItem(int row, int column, QTableWidgetItem * item);//Sets the item for the given row and column to item.//表格接管了该项的所有权。//请注意，如果已启用排序(参见`sortingEnabled`)，且列是当前排序列，//  则该行将被移动到由`item`确定的已排序位置。//如果您想设置某一行中的多个项(例如，通过循环调用setltem())，可能需要在操作前关闭排序功能，//然后在操作后重新开启;这样您就可以为同一行中的所有项使用相同的行参数(即，setltem()不会移动该行)。QTableWidgetItem *    takeItem(int row, int column);//Removes the item at row and column from the table without deleting it.//Returns a list of pointers to the items contained in the data object.//If the object was not created by a QTreeWidget in the same process, the list is empty.QList<QTableWidgetItem *> items(const QMimeData * data) const;//Returns the row / column for the item.int    row(const QTableWidgetItem * item) const;int column(const QTableWidgetItem * item) const;//Returns the QModelIndex associated with the given item.条目索引与指针之间的相互转换。QModelIndex      indexFromItem         (const QTableWidgetItem * item ) const;QTableWidgetItem *        itemFromIndex(const QModelIndex      & index) const;//Returns a pointer to the QTableWidgetItem associated with the given index.//Returns the row / Column of the current item.int                     currentRow   () const;int                     currentColumn() const;QTableWidgetItem *      currentItem  () const;void                 setCurrentItem(QTableWidgetItem * item); //以代码的方式选择条目。//Sets the current item to item.//Unless the selection mode is NoSelection, the item is also selected.void                 setCurrentItem(QTableWidgetItem * item,QItemSelectionModel::SelectionFlags command);void                 setCurrentCell(int row, int column);     //直接用行列下标设定条目void                 setCurrentCell(int row, int column,      //这样更好。QItemSelectionModel::SelectionFlags command);bool    isSortingEnabled() const;       //默认，表格排序是被禁止的。void   setSortingEnabled(bool enable);  //无注释void      sortItems(int column, Qt::SortOrder order = Qt::AscendingOrder);//Sorts all the rows in the table widget based on column and order.//按某列排序，影响的不仅仅本列，而是所有的行。整行都因为某列的排序而移动了。int visualRow   (int logicalRow   ) const; //返回逻辑索引与视觉索引的对应关系int visualColumn(int logicalColumn) const; //隐藏并不会改变视觉索引。//Returns the widget displayed in the cell in the given row and column.//Note: The table takes ownership of the widget.//测试说明，这个窗体组件，不属于表中元素，不是先天就存在的。未设置前，是 nullptr。QWidget *       cellWidget(int row, int column) const;void         setCellWidget(int row, int column, QWidget * widget);inline    //Removes the widget set on the cell indicated by row and column.void      removeCellWidget(int row, int column){   setCellWidget(row, column, nullptr); }QList<QTableWidgetItem *>         selectedItems () const; //处理多选用这个就够//Returns a list of all selected ranges.QList<QTableWidgetSelectionRange> selectedRanges() const;void setRangeSelected(const QTableWidgetSelectionRange & range, bool select);//Selects or deselects the range depending on select.//QModelIndex QAbstractItemView::indexAt(const QPoint & point)基类里还有这个成员函数//Returns a pointer to the item at the given point,//  or returns nullptr if point is not covered by an item in the table widget.QTableWidgetItem * itemAt(const QPoint & p) const;inlineQTableWidgetItem * itemAt(int x,     int y) const //采用了表格自己的坐标系。{   return itemAt(QPoint(x, y)); }//Returns the item at the position equivalent to QPoint(ax, ay) in the//  table widget's coordinate system,QList<QTableWidgetItem *> findItems(const QString & text, Qt::MatchFlags flags) const;//Finds items that matches the text using the given flags./*//This enum describes the type of matches that can be//  used when searching for items in a model.enum Qt::MatchFlag { //本枚举量用于组合框的条目搜索。本枚举量指定了搜索方式MatchExactly           = 0, //Performs QVariant-based matching.MatchContains          = 1, //The search term is contained in the item.MatchStartsWith        = 2, //The search term matches the start of the item.MatchEndsWith          = 3, //The search term matches the   end of the item.MatchRegularExpression = 4,MatchWildcard          = 5,MatchFixedString       = 8,MatchTypeMask      = 0x0F,MatchCaseSensitive = 16,    //The search is case sensitive.MatchWrap          = 32,MatchRecursive     = 64     //Searches the entire hierarchy.};Q_DECLARE_FLAGS(MatchFlags, MatchFlag)Q_DECLARE_OPERATORS_FOR_FLAGS(MatchFlags)*/const  //Returns the item prototype used by the table.QTableWidgetItem *    itemPrototype() const; //似乎在继承 QTableWidgetltem时才用得上void               setItemPrototype(const QTableWidgetItem *item);// Sets the item prototype for the table to the specified item.//该表格小部件在需要创建新的表格项时，将使用项原型克隆函数。//例如，当用户在空单元格中进行编辑时。这非常有用，//尤其是在您有 QTableWidgetltem 子类并且希望确保 QTableWidget 创建您的子类实例的情况下。//表格接管原型的所有权。//返回某个单元格的位置信息QRect visualItemRect(const QTableWidgetItem * item) const; //无注释using  QAbstractItemView::isPersistentEditorOpen;/*class QAbstractItemView {bool      isPersistentEditorOpen(const QModelIndex & index) const;void    openPersistentEditor    (const QModelIndex & index);void   closePersistentEditor    (const QModelIndex & index);}*///Returns whether a persistent editor is open for item item.bool    isPersistentEditorOpen(QTableWidgetItem * item) const; //函数重载，参数类型不一样//Starts editing the item if it is editable.void                editItem  (QTableWidgetItem * item); //打开的是普通易失编辑框void  openPersistentEditor    (QTableWidgetItem * item); //打开持久型编辑框//Opens an editor for the give item. The editor remains open after editing.void closePersistentEditor    (QTableWidgetItem * item); //只有调用本函数才可以关闭持久框//Closes the persistent editor for item.protected:bool     event(QEvent     * e    ) override;void dropEvent(QDropEvent * event) override;virtual QStringList        mimeTypes() const;virtual QMimeData   *      mimeData(const QList<QTableWidgetItem *> & items) const;virtual bool           dropMimeData(int row, int column,const QMimeData * data, Qt::DropAction action);virtual Qt::DropActions supportedDropActions() const;//Returns the drop actions supported by this view./*enum Qt::DropAction { //本枚举类用于描述模型视图里的拖动操作的语义：复制、剪切或超链接。CopyAction       = 0x   1, //Copy the data to the target.MoveAction       = 0x   2, //Move the data from the source to the target.LinkAction       = 0x   4, //Create a link from the source to the target.ActionMask       = 0x  ff,TargetMoveAction = 0x8002, //在 Windows上，当 D&D数据的所有权应被目标应用程序接管时，//即源应用程序不应删除这些数据时，会使用此值。//在X11上，此值用于执行移动操作。Mac上不使用TargetMoveAction。IgnoreAction     = 0x   0  //Ignore the action (do nothing with the data).};Q_DECLARE_FLAGS(DropActions, DropAction)Q_DECLARE_OPERATORS_FOR_FLAGS(DropActions)*/public Q_SLOTS://Scrolls the view if necessary to ensure that the item is visible.//The hint parameter specifies more precisely where the//  item should be located after the operation.void   scrollToItem(const QTableWidgetItem * item,QAbstractItemView::ScrollHint hint = EnsureVisible);/*enum QAbstractItemView::ScrollHint {EnsureVisible   , //Scroll to ensure that the item is visible.PositionAtTop   , //Scroll to position the item at the top    of the viewport.PositionAtBottom, //Scroll to position the item at the bottom of the viewport.PositionAtCenter  //Scroll to position the item at the center of the viewport.};Q_ENUM(ScrollHint)    //滚动屏幕到条目 index处，并指明了 index条目的新的位置virtual void QAbstractItemView::scrollTo(const QModelIndex & index,ScrollHint hint = EnsureVisible) = 0;*///Inserts an empty row into the table at row.void insertRow   (int row   ); //在行 row ，列 column处插入一行或一列。void insertColumn(int column);void removeRow(int row);void removeColumn(int column); //删除第 row行或第 column列。//Removes the column column and all its items from the table.//Removes all items in the view. This will also remove all selections and headers.//If you don't want to remove the headers, use QTableWidget::clearContents().//The table dimensions stay the same.void clear        (); //行列框架        还会保存，表头数据没有了，改成了123数字void clearContents(); //行列框架和表头数据都会保存，只清除表体中的数据，置为空。//Removes all items not in the headers from the view.//This will also remove all selections. The table dimensions stay the same.Q_SIGNALS:void itemEntered(QTableWidgetItem * item);void cellEntered(int row,     int column);void itemPressed(QTableWidgetItem * item);void cellPressed(int row,     int column);void itemClicked(QTableWidgetItem * item);void cellClicked(int row,     int column);//This signal is emitted when the specified item has been activatedvoid itemActivated(QTableWidgetItem * item);void cellActivated(int row,     int column);void itemDoubleClicked(QTableWidgetItem * item);void cellDoubleClicked(int row,     int column);//This signal is emitted whenever the data of item has changed.void itemChanged(QTableWidgetItem * item); //当条目里的数据改变时，触发本信号void cellChanged(int row,     int column);//This signal is emitted whenever the current item changes.//The previous item is the item that previously had the focus,//  current is the new current item.       //当焦点切换时触发本信号函数。// 经测试发现，本信号函数里的 previous 形参不要使用。否则程序会闪退。void currentItemChanged(QTableWidgetItem * current, QTableWidgetItem * previous);void currentCellChanged(int  currentRow, int  currentColumn,int previousRow, int previousColumn);void itemSelectionChanged(); //当焦点选择变化时触发本信号，但没有形参。//This signal is emitted whenever the selection changes.}; //完结 class QTableWidget : public QTableViewQT_END_NAMESPACE#endif // QTABLEWIDGET_H

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