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QSortFilterProxyModel Class

QSortFilterProxyModel class provides support for sorting and filtering data passed between another model and a view. 更多...

头： #include <QSortFilterProxyModel>
qmake: QT += core
Since: Qt 4.1
继承： QAbstractProxyModel

特性

公共函数

QSortFilterProxyModel (QObject * parent = Q_NULLPTR)
~QSortFilterProxyModel ()
bool dynamicSortFilter () const
Qt::CaseSensitivity filterCaseSensitivity () const
int filterKeyColumn () const
QRegExp filterRegExp () const
int filterRole () const
bool isSortLocaleAware () const
void setDynamicSortFilter (bool enable )
void setFilterCaseSensitivity (Qt::CaseSensitivity cs )
void setFilterKeyColumn (int column )
void setFilterRegExp (const QRegExp & regExp )
void setFilterRole (int role )
void setSortCaseSensitivity (Qt::CaseSensitivity cs )
void setSortLocaleAware (bool on )
void setSortRole (int role )
Qt::CaseSensitivity sortCaseSensitivity () const
int sortColumn () const
Qt::SortOrder sortOrder () const
int sortRole () const

重实现公共函数

virtual QModelIndex buddy (const QModelIndex & index ) const
virtual bool canFetchMore (const QModelIndex & parent ) const
virtual int columnCount (const QModelIndex & parent = QModelIndex()) const
virtual QVariant data (const QModelIndex & index , int role = Qt::DisplayRole) const
virtual bool dropMimeData (const QMimeData * data , Qt::DropAction action , int row , int column , const QModelIndex & parent )
virtual void fetchMore (const QModelIndex & parent )
virtual Qt::ItemFlags flags (const QModelIndex & index ) const
virtual bool hasChildren (const QModelIndex & parent = QModelIndex()) const
virtual QVariant headerData (int section , Qt::Orientation orientation , int role = Qt::DisplayRole) const
virtual QModelIndex index (int row , int column , const QModelIndex & parent = QModelIndex()) const
virtual bool insertColumns (int column , int count , const QModelIndex & parent = QModelIndex())
virtual bool insertRows (int row , int count , const QModelIndex & parent = QModelIndex())
virtual QModelIndex mapFromSource (const QModelIndex & sourceIndex ) const
virtual QItemSelection mapSelectionFromSource (const QItemSelection & sourceSelection ) const
virtual QItemSelection mapSelectionToSource (const QItemSelection & proxySelection ) const
virtual QModelIndex mapToSource (const QModelIndex & proxyIndex ) const
virtual QModelIndexList match (const QModelIndex & start , int role , const QVariant & value , int hits = 1, Qt::MatchFlags flags = Qt::MatchFlags( Qt::MatchStartsWith | Qt::MatchWrap )) const
virtual QMimeData * mimeData (const QModelIndexList & indexes ) const
virtual QStringList mimeTypes () const
virtual QModelIndex parent (const QModelIndex & child ) const
virtual bool removeColumns (int column , int count , const QModelIndex & parent = QModelIndex())
virtual bool removeRows (int row , int count , const QModelIndex & parent = QModelIndex())
virtual int rowCount (const QModelIndex & parent = QModelIndex()) const
virtual bool setData (const QModelIndex & index , const QVariant & value , int role = Qt::EditRole)
virtual bool setHeaderData (int section , Qt::Orientation orientation , const QVariant & value , int role = Qt::EditRole)
virtual void setSourceModel (QAbstractItemModel * sourceModel )
virtual QModelIndex sibling (int row , int column , const QModelIndex & idx ) const
virtual void sort (int column , Qt::SortOrder order = Qt::AscendingOrder)
virtual QSize span (const QModelIndex & index ) const
virtual Qt::DropActions supportedDropActions () const

公共槽

void invalidate ()
void setFilterFixedString (const QString & pattern )
void setFilterRegExp (const QString & pattern )
void setFilterWildcard (const QString & pattern )

保护函数

virtual bool filterAcceptsColumn (int source_column , const QModelIndex & source_parent ) const
virtual bool filterAcceptsRow (int source_row , const QModelIndex & source_parent ) const
void invalidateFilter ()
virtual bool lessThan (const QModelIndex & source_left , const QModelIndex & source_right ) const

额外继承成员

详细描述

QSortFilterProxyModel class provides support for sorting and filtering data passed between another model and a view.

QSortFilterProxyModel can be used for sorting items, filtering out items, or both. The model transforms the structure of a source model by mapping the model indexes it supplies to new indexes, corresponding to different locations, for views to use. This approach allows a given source model to be restructured as far as views are concerned without requiring any transformations on the underlying data, and without duplicating the data in memory.

Let's assume that we want to sort and filter the items provided by a custom model. The code to set up the model and the view, without sorting and filtering, would look like this: 

        QTreeView *treeView = new QTreeView;
        MyItemModel *model = new MyItemModel(this);
        treeView->setModel(model);

To add sorting and filtering support to MyItemModel , we need to create a QSortFilterProxyModel ，调用 setSourceModel () 采用 MyItemModel as argument, and install the QSortFilterProxyModel on the view: 

        QTreeView *treeView = new QTreeView;
        MyItemModel *sourceModel = new MyItemModel(this);
        QSortFilterProxyModel *proxyModel = new QSortFilterProxyModel(this);
        proxyModel->setSourceModel(sourceModel);
        treeView->setModel(proxyModel);

At this point, neither sorting nor filtering is enabled; the original data is displayed in the view. Any changes made through the QSortFilterProxyModel are applied to the original model.

QSortFilterProxyModel acts as a wrapper for the original model. If you need to convert source QModelIndex es to sorted/filtered model indexes or vice versa, use mapToSource (), mapFromSource (), mapSelectionToSource ()，和 mapSelectionFromSource ().

注意： By default, the model dynamically re-sorts and re-filters data whenever the original model changes. This behavior can be changed by setting the dynamicSortFilter 特性。

Basic Sort/Filter Model and Custom Sort/Filter Model 范例阐明如何使用 QSortFilterProxyModel to perform basic sorting and filtering and how to subclass it to implement custom behavior.

排序

QTableView and QTreeView have a sortingEnabled property that controls whether the user can sort the view by clicking the view's horizontal header. For example: 

        treeView->setSortingEnabled(true);

When this feature is on (the default is off), clicking on a header section sorts the items according to that column. By clicking repeatedly, the user can alternate between ascending and descending order.

A sorted QTreeView

Behind the scene, the view calls the sort () virtual function on the model to reorder the data in the model. To make your data sortable, you can either implement sort () in your model, or use a QSortFilterProxyModel to wrap your model -- QSortFilterProxyModel provides a generic sort () reimplementation that operates on the sortRole () ( Qt::DisplayRole by default) of the items and that understands several data types, including int , QString ，和 QDateTime . For hierarchical models, sorting is applied recursively to all child items. String comparisons are case sensitive by default; this can be changed by setting the sortCaseSensitivity 特性。

Custom sorting behavior is achieved by subclassing QSortFilterProxyModel 和重实现 lessThan (), which is used to compare items. For example: 

bool MySortFilterProxyModel::lessThan(const QModelIndex &left,
                                      const QModelIndex &right) const
{
    QVariant leftData = sourceModel()->data(left);
    QVariant rightData = sourceModel()->data(right);
    if (leftData.type() == QVariant::DateTime) {
        return leftData.toDateTime() < rightData.toDateTime();
    } else {
        static QRegExp emailPattern("[\\w\\.]*@[\\w\\.]*)");
        QString leftString = leftData.toString();
        if(left.column() == 1 && emailPattern.indexIn(leftString) != -1)
            leftString = emailPattern.cap(1);
        QString rightString = rightData.toString();
        if(right.column() == 1 && emailPattern.indexIn(rightString) != -1)
            rightString = emailPattern.cap(1);
        return QString::localeAwareCompare(leftString, rightString) < 0;
    }
}

(This code snippet comes from the Custom Sort/Filter Model example.)

An alternative approach to sorting is to disable sorting on the view and to impose a certain order to the user. This is done by explicitly calling sort () with the desired column and order as arguments on the QSortFilterProxyModel (or on the original model if it implements sort ()). For example: 

        proxyModel->sort(2, Qt::AscendingOrder);

QSortFilterProxyModel can be sorted by column -1, in which case it returns to the sort order of the underlying source model.

过滤

In addition to sorting, QSortFilterProxyModel can be used to hide items that do not match a certain filter. The filter is specified using a QRegExp object and is applied to the filterRole () ( Qt::DisplayRole by default) of each item, for a given column. The QRegExp object can be used to match a regular expression, a wildcard pattern, or a fixed string. For example: 

        proxyModel->setFilterRegExp(QRegExp(".png", Qt::CaseInsensitive,
                                            QRegExp::FixedString));
        proxyModel->setFilterKeyColumn(1);

For hierarchical models, the filter is applied recursively to all children. If a parent item doesn't match the filter, none of its children will be shown.

A common use case is to let the user specify the filter regexp, wildcard pattern, or fixed string in a QLineEdit and to connect the textChanged() signal to setFilterRegExp (), setFilterWildcard ()，或 setFilterFixedString () to reapply the filter.

Custom filtering behavior can be achieved by reimplementing the filterAcceptsRow () 和 filterAcceptsColumn () functions. For example (from the Custom Sort/Filter Model example), the following implementation ignores the filterKeyColumn property and performs filtering on columns 0, 1, and 2: 

bool MySortFilterProxyModel::filterAcceptsRow(int sourceRow,
        const QModelIndex &sourceParent) const
{
    QModelIndex index0 = sourceModel()->index(sourceRow, 0, sourceParent);
    QModelIndex index1 = sourceModel()->index(sourceRow, 1, sourceParent);
    QModelIndex index2 = sourceModel()->index(sourceRow, 2, sourceParent);
    return (sourceModel()->data(index0).toString().contains(filterRegExp())
            || sourceModel()->data(index1).toString().contains(filterRegExp()))
            && dateInRange(sourceModel()->data(index2).toDate());
}

(This code snippet comes from the Custom Sort/Filter Model example.)

If you are working with large amounts of filtering and have to invoke invalidateFilter () repeatedly, using reset() may be more efficient, depending on the implementation of your model. However, reset() returns the proxy model to its original state, losing selection information, and will cause the proxy model to be repopulated.

子类化

由于 QAbstractProxyModel and its subclasses are derived from QAbstractItemModel , much of the same advice about subclassing normal models also applies to proxy models. In addition, it is worth noting that many of the default implementations of functions in this class are written so that they call the equivalent functions in the relevant source model. This simple proxying mechanism may need to be overridden for source models with more complex behavior; for example, if the source model provides a custom hasChildren () implementation, you should also provide one in the proxy model.

注意： Some general guidelines for subclassing models are available in the 模型子类化参考 .

另请参阅 QAbstractProxyModel , QAbstractItemModel , 模型/视图编程 , 基本排序/过滤模型范例 , 自定义排序/过滤模型范例 ，和 QIdentityProxyModel .

特性文档编制

dynamicSortFilter : bool

This property holds whether the proxy model is dynamically sorted and filtered whenever the contents of the source model change

Note that you should not update the source model through the proxy model when dynamicSortFilter is true. For instance, if you set the proxy model on a QComboBox , then using functions that update the model, e.g., addItem() , will not work as expected. An alternative is to set dynamicSortFilter to false and call sort() after adding items to the QComboBox .

默认值为 true。

该特性在 Qt 4.2 引入。

访问函数：

bool dynamicSortFilter () const
void setDynamicSortFilter (bool enable )

filterCaseSensitivity : Qt::CaseSensitivity

This property holds the case sensitivity of the QRegExp pattern used to filter the contents of the source model

By default, the filter is case sensitive.

访问函数：

Qt::CaseSensitivity filterCaseSensitivity () const
void setFilterCaseSensitivity (Qt::CaseSensitivity cs )

另请参阅 filterRegExp and sortCaseSensitivity .

filterKeyColumn : int

This property holds the column where the key used to filter the contents of the source model is read from.

The default value is 0. If the value is -1, the keys will be read from all columns.

访问函数：

int filterKeyColumn () const
void setFilterKeyColumn (int column )

filterRegExp : QRegExp

此特性保持 QRegExp used to filter the contents of the source model

Setting this property overwrites the current filterCaseSensitivity . By default, the QRegExp is an empty string matching all contents.

若无 QRegExp or an empty string is set, everything in the source model will be accepted.

访问函数：

QRegExp filterRegExp () const
void setFilterRegExp (const QRegExp & regExp )
void setFilterRegExp (const QString & pattern )

另请参阅 filterCaseSensitivity , setFilterWildcard ()，和 setFilterFixedString ().

filterRole : int

This property holds the item role that is used to query the source model's data when filtering items

默认值为 Qt::DisplayRole .

该特性在 Qt 4.2 引入。

访问函数：

int filterRole () const
void setFilterRole (int role )

另请参阅 filterAcceptsRow ().

isSortLocaleAware : bool

This property holds the local aware setting used for comparing strings when sorting

By default, sorting is not local aware.

该特性在 Qt 4.3 引入。

访问函数：

bool isSortLocaleAware () const
void setSortLocaleAware (bool on )

另请参阅 sortCaseSensitivity and lessThan ().

sortCaseSensitivity : Qt::CaseSensitivity

This property holds the case sensitivity setting used for comparing strings when sorting

By default, sorting is case sensitive.

该特性在 Qt 4.2 引入。

访问函数：

Qt::CaseSensitivity sortCaseSensitivity () const
void setSortCaseSensitivity (Qt::CaseSensitivity cs )

另请参阅 filterCaseSensitivity and lessThan ().

sortRole : int

This property holds the item role that is used to query the source model's data when sorting items

默认值为 Qt::DisplayRole .

该特性在 Qt 4.2 引入。

访问函数：

int sortRole () const
void setSortRole (int role )

另请参阅 lessThan ().

成员函数文档编制

QSortFilterProxyModel:: QSortFilterProxyModel ( QObject * parent = Q_NULLPTR)

Constructs a sorting filter model with the given parent .

QSortFilterProxyModel:: ~QSortFilterProxyModel ()

Destroys this sorting filter model.

[virtual] QModelIndex QSortFilterProxyModel:: buddy (const QModelIndex & index ) const

重实现自 QAbstractItemModel::buddy ().

[virtual] bool QSortFilterProxyModel:: canFetchMore (const QModelIndex & parent ) const

重实现自 QAbstractItemModel::canFetchMore ().

[virtual] int QSortFilterProxyModel:: columnCount (const QModelIndex & parent = QModelIndex()) const

重实现自 QAbstractItemModel::columnCount ().

[virtual] QVariant QSortFilterProxyModel:: data (const QModelIndex & index , int role = Qt::DisplayRole) const

重实现自 QAbstractItemModel::data ().

另请参阅 setData ().

[virtual] bool QSortFilterProxyModel:: dropMimeData (const QMimeData * data , Qt::DropAction action , int row , int column , const QModelIndex & parent )

重实现自 QAbstractItemModel::dropMimeData ().

[virtual] void QSortFilterProxyModel:: fetchMore (const QModelIndex & parent )

重实现自 QAbstractItemModel::fetchMore ().

[virtual protected] bool QSortFilterProxyModel:: filterAcceptsColumn ( int source_column , const QModelIndex & source_parent ) const

返回 true if the item in the column indicated by the given source_column and source_parent should be included in the model; otherwise returns false .

默认实现返回 true if the value held by the relevant item matches the filter string, wildcard string or regular expression.

注意： 默认情况下， Qt::DisplayRole is used to determine if the column should be accepted or not. This can be changed by setting the filterRole 特性。

另请参阅 filterAcceptsRow (), setFilterFixedString (), setFilterRegExp ()，和 setFilterWildcard ().

[virtual protected] bool QSortFilterProxyModel:: filterAcceptsRow ( int source_row , const QModelIndex & source_parent ) const

返回 true if the item in the row indicated by the given source_row and source_parent should be included in the model; otherwise returns false.

默认实现返回 true if the value held by the relevant item matches the filter string, wildcard string or regular expression.

注意： 默认情况下， Qt::DisplayRole is used to determine if the row should be accepted or not. This can be changed by setting the filterRole 特性。

另请参阅 filterAcceptsColumn (), setFilterFixedString (), setFilterRegExp ()，和 setFilterWildcard ().

[virtual] Qt::ItemFlags QSortFilterProxyModel:: flags (const QModelIndex & index ) const

重实现自 QAbstractItemModel::flags ().

[virtual] bool QSortFilterProxyModel:: hasChildren (const QModelIndex & parent = QModelIndex()) const

重实现自 QAbstractItemModel::hasChildren ().

[virtual] QVariant QSortFilterProxyModel:: headerData ( int section , Qt::Orientation orientation , int role = Qt::DisplayRole) const

重实现自 QAbstractItemModel::headerData ().

另请参阅 setHeaderData ().

[virtual] QModelIndex QSortFilterProxyModel:: index ( int row , int column , const QModelIndex & parent = QModelIndex()) const

重实现自 QAbstractItemModel::index ().

[virtual] bool QSortFilterProxyModel:: insertColumns ( int column , int count , const QModelIndex & parent = QModelIndex())

重实现自 QAbstractItemModel::insertColumns ().

[virtual] bool QSortFilterProxyModel:: insertRows ( int row , int count , const QModelIndex & parent = QModelIndex())

重实现自 QAbstractItemModel::insertRows ().

[slot] void QSortFilterProxyModel:: invalidate ()

Invalidates the current sorting and filtering.

该函数在 Qt 4.3 引入。

另请参阅 invalidateFilter ().

[protected] void QSortFilterProxyModel:: invalidateFilter ()

Invalidates the current filtering.

This function should be called if you are implementing custom filtering (e.g. filterAcceptsRow ()), and your filter parameters have changed.

该函数在 Qt 4.3 引入。

另请参阅 invalidate ().

[virtual protected] bool QSortFilterProxyModel:: lessThan (const QModelIndex & source_left , const QModelIndex & source_right ) const

返回 true if the value of the item referred to by the given index source_left is less than the value of the item referred to by the given index source_right ，否则返回 false .

This function is used as the < operator when sorting, and handles the following QVariant types:

Any other type will be converted to a QString 使用 QVariant::toString ().

Comparison of QString s is case sensitive by default; this can be changed using the sortCaseSensitivity 特性。

默认情况下， Qt::DisplayRole associated with the QModelIndex es is used for comparisons. This can be changed by setting the sortRole 特性。

注意： The indices passed in correspond to the source model.

另请参阅 sortRole , sortCaseSensitivity ，和 dynamicSortFilter .

[virtual] QModelIndex QSortFilterProxyModel:: mapFromSource (const QModelIndex & sourceIndex ) const

重实现自 QAbstractProxyModel::mapFromSource ().

Returns the model index in the QSortFilterProxyModel given the sourceIndex from the source model.

另请参阅 mapToSource ().

[virtual] QItemSelection QSortFilterProxyModel:: mapSelectionFromSource (const QItemSelection & sourceSelection ) const

重实现自 QAbstractProxyModel::mapSelectionFromSource ().

[virtual] QItemSelection QSortFilterProxyModel:: mapSelectionToSource (const QItemSelection & proxySelection ) const

重实现自 QAbstractProxyModel::mapSelectionToSource ().

[virtual] QModelIndex QSortFilterProxyModel:: mapToSource (const QModelIndex & proxyIndex ) const

重实现自 QAbstractProxyModel::mapToSource ().

Returns the source model index corresponding to the given proxyIndex from the sorting filter model.

另请参阅 mapFromSource ().

[virtual] QModelIndexList QSortFilterProxyModel:: match (const QModelIndex & start , int role , const QVariant & value , int hits = 1, Qt::MatchFlags flags = Qt::MatchFlags( Qt::MatchStartsWith | Qt::MatchWrap )) const

重实现自 QAbstractItemModel::match ().

[virtual] QMimeData *QSortFilterProxyModel:: mimeData (const QModelIndexList & indexes ) const

重实现自 QAbstractItemModel::mimeData ().

[virtual] QStringList QSortFilterProxyModel:: mimeTypes () const

重实现自 QAbstractItemModel::mimeTypes ().

[virtual] QModelIndex QSortFilterProxyModel:: parent (const QModelIndex & child ) const

重实现自 QAbstractItemModel::parent ().

[virtual] bool QSortFilterProxyModel:: removeColumns ( int column , int count , const QModelIndex & parent = QModelIndex())

重实现自 QAbstractItemModel::removeColumns ().

[virtual] bool QSortFilterProxyModel:: removeRows ( int row , int count , const QModelIndex & parent = QModelIndex())

重实现自 QAbstractItemModel::removeRows ().

[virtual] int QSortFilterProxyModel:: rowCount (const QModelIndex & parent = QModelIndex()) const

重实现自 QAbstractItemModel::rowCount ().

[virtual] bool QSortFilterProxyModel:: setData (const QModelIndex & index , const QVariant & value , int role = Qt::EditRole)

重实现自 QAbstractItemModel::setData ().

另请参阅 data ().

[slot] void QSortFilterProxyModel:: setFilterFixedString (const QString & pattern )

Sets the fixed string used to filter the contents of the source model to the given pattern .

另请参阅 setFilterCaseSensitivity (), setFilterRegExp (), setFilterWildcard ()，和 filterRegExp ().

[slot] void QSortFilterProxyModel:: setFilterRegExp (const QString & pattern )

这是重载函数。

Sets the regular expression used to filter the contents of the source model to pattern .

注意： Setter 函数对于特性 filterRegExp .

另请参阅 setFilterCaseSensitivity (), setFilterWildcard (), setFilterFixedString ()，和 filterRegExp ().

[slot] void QSortFilterProxyModel:: setFilterWildcard (const QString & pattern )

Sets the wildcard expression used to filter the contents of the source model to the given pattern .

另请参阅 setFilterCaseSensitivity (), setFilterRegExp (), setFilterFixedString ()，和 filterRegExp ().

[virtual] bool QSortFilterProxyModel:: setHeaderData ( int section , Qt::Orientation orientation , const QVariant & value , int role = Qt::EditRole)

重实现自 QAbstractItemModel::setHeaderData ().

另请参阅 headerData ().

[virtual] void QSortFilterProxyModel:: setSourceModel ( QAbstractItemModel * sourceModel )

重实现自 QAbstractProxyModel::setSourceModel ().

[virtual] QModelIndex QSortFilterProxyModel:: sibling ( int row , int column , const QModelIndex & idx ) const

重实现自 QAbstractItemModel::sibling ().

[virtual] void QSortFilterProxyModel:: sort ( int column , Qt::SortOrder order = Qt::AscendingOrder)

重实现自 QAbstractItemModel::sort ().

int QSortFilterProxyModel:: sortColumn () const

the column currently used for sorting

This returns the most recently used sort column.

该函数在 Qt 4.5 引入。

Qt::SortOrder QSortFilterProxyModel:: sortOrder () const

the order currently used for sorting

This returns the most recently used sort order.

该函数在 Qt 4.5 引入。

[virtual] QSize QSortFilterProxyModel:: span (const QModelIndex & index ) const

重实现自 QAbstractItemModel::span ().

[virtual] Qt::DropActions QSortFilterProxyModel:: supportedDropActions () const

重实现自 QAbstractItemModel::supportedDropActions ().