我有一个QTreeView
,在根节点下有三个分支
QTreeView treeView_4 = new QTreeView(tab_10);
QStandardItemModel standardModel = new QStandardItemModel ;
QStandardItem *rootNode = standardModel->invisibleRootItem();
QStandardItem Group1Item = new QStandardItem("Group 1");
QStandardItem Group2Item = new QStandardItem("Group 2");
QStandardItem Group3Item = new QStandardItem("Group 3");
rootNode->appendRow(Group1Item);
rootNode->appendRow(Group2Item);
rootNode->appendRow(Group3Item);
我想在创建Group1 / 2/3时列出一些对象。当Object的属性发生变化时,我想将它们从一个组移动到另一个组(就像某些状态更改一样)。对象有两个对QTreeView感兴趣的属性:QString IPaddress
和QString Name
。 (我想在QtreeView上显示其中任何一个)
这样做的最佳/正确方法是什么?
class Object : public QObject
{
Q_OBJECT
public:
//.... some properties, get and set functions, etc.
QStandardItem *NodeItemIP;
QStandardItem *NodeItemName;
private:
QString Name;
QString IPaddr;
///....
}
我将对象存储在QVector
:QVector<Object*> mObject
我为每个群组使用QMap
做了什么来跟踪
QMap<QString, QString> group1MapList;
QMap<QString, QString> group2MapList;
QMap<QString, QString> group3MapList;
当它们附加到insert
时,和Qmap
将它们传递给QStandardItem
group1MapList.insert(mObject[1]->getName(), mObject[1]->getIPaddr());
Group1Item.appendRow(mObject[1]->NodeItemIP);
或
int index = 0;
QMap<QString, QString>::Iterator it;
for (it=group1MapList.begin(); it != group1MapList.end(); it++){
if(it.value() == IPAddrToRemove){
group1MapList.remove(IPAddrToRemove);
Group1Item->removeRow(index);
break;
}
index++;
}
我注意到QMap
(以及QHash
)也没有按照添加顺序存储实体。
是否有任何特殊课程可以跟踪我需要的QStandardItems,还是应该使用 QVector 或其他任何内容?
由于我有两个属性:IPaddr
和Name
,我是否需要有两个QVector
来跟踪它们,或者某些内容可以处理它们?
注意:如果没有复制+粘贴/编辑错误,那么上面的代码片段&#39;语法应该没问题。
答案 0 :(得分:1)
如果您正在使用QTreeView
,则可能必须创建自定义数据结构以对数据树进行建模。像这样:
struct ModelItem
{
QString groupName;
QString name;
QString IPaddr;
ModelItem* parent;
std::vector< ModelItem* > childs;
ModelItem( const QString& a_name )
: name( a_name ),
parent( nullptr )
{ }
~ModelItem( )
{
for ( auto it = childs.begin( ); it != childs.end( ); ++it )
delete *it;
}
void AddChild( ModelItem* children )
{
childs.push_back( children );
children->parent = this;
}
};
当然,您需要继承QAbstractItemModel
:
class CustomModel : public QAbstractItemModel
{
Q_OBJECT
public:
CustomModel( QObject* parent = nullptr );
~CustomModel( );
int columnCount( const QModelIndex& parent ) const override;
int rowCount( const QModelIndex& parent ) const override;
QVariant data( const QModelIndex& index,
int role = Qt::DisplayRole ) const override;
QModelIndex index ( int row,
int column,
const QModelIndex& parent ) const override;
QModelIndex parent( const QModelIndex & index ) const override;
void SetGroup( const QString& groupName,
const std::vector< std::pair< QString, QString > >& items );
void ResetModel( );
private:
ModelItem rootNode;
};
columnCount和rowCount方法应返回模型的列数/行数:
int CustomModel::columnCount( const QModelIndex& /* parent */ ) const
{
return 1;
}
int CustomModel::rowCount( const QModelIndex& parent ) const
{
int to_return;
if ( parent.isValid( ) )
{
ModelItem* node = static_cast< ModelItem* >( parent.internalPointer( ) );
to_return = node->childs.size( );
}
else
to_return = rootNode.childs.size( );
return to_return;
}
数据方法应返回模型的内容:
QVariant CustomModel::data( const QModelIndex& index,
int role ) const
{
QVariant to_return;
if ( index.isValid( ) ) // if not valid, current index is root node
{
switch ( role )
{
case Qt::DisplayRole: // you can manage other roles to enrich the view
{
ModelItem* node = static_cast< ModelItem* >( index.internalPointer( ) );
to_return = node->name;
break;
}
}
}
return to_return;
}
索引将创建给定节点的适当QModelIndex
:
QModelIndex CustomModel::index ( int row,
int column,
const QModelIndex& parent ) const
{
QModelIndex to_return;
if ( ( row >= 0 && row < rowCount( parent ) )
&& ( column >= 0 && column <= columnCount( parent ) ) )
{
if ( parent.isValid( ) )
{
ModelItem* item = static_cast< ModelItem* >( parent.internalPointer( ) );
to_return = createIndex( row, column, item->childs.at( row ) );
}
else
{
to_return = createIndex( row, column, rootNode.childs.at( row ) );
}
}
return to_return;
}
父方法应返回给定节点的父级索引
QModelIndex CustomModel::parent( const QModelIndex & index ) const
{
QModelIndex to_return;
if ( index.isValid( ) )
{
ModelItem* node = static_cast< ModelItem* >( index.internalPointer( ) );
ModelItem* parent = node->parent;
ModelItem* parent2 = parent->parent;
if ( parent2 ) // node->parent can be root node
{
auto it = std::find_if( parent2->childs.begin( ), parent2->childs.end( ),
[&]( ModelItem* child ){ return child == parent; } );
if ( it != parent2->childs.end( ) )
{
int row = std::distance( parent2->childs.begin( ), it );
to_return = createIndex( row, 0, parent );
}
}
}
return to_return;
}
下一个方法:SetGroup。使用此方法,我们可以向模型添加数据:
void CustomModel::SetGroup( const QString& groupName,
const std::vector< std::pair< QString, QString > >& items )
{
// Notify to view that we will insert a new group
beginInsertRows( QModelIndex( ), rootNode.childs.size( ), rootNode.childs.size( ) );
ModelItem* groupNode = new ModelItem( groupName );
rootNode.AddChild( groupNode );
for ( auto it = items.begin( ); it != items.end( ); ++it )
{
ModelItem* node = new ModelItem( it->first );
node->name = it->first;
node->IPaddr = it->second;
groupNode->AddChild( node );
}
endInsertRows( );
}
ResetModel方法只需清理视图:
void CustomModel::ResetModel( )
{
beginResetModel( );
rootNode= ModelItem( "root" );
endResetModel( );
}
完成模型实施后,我们只需要将数据发送到模型和链接模型并查看:
QTreeView* treeView_4 = new QTreeView( tab_10 );
CustomModel* model = new CustomModel( this );
std::vector< std::pair< QString, QString > > data;
data.push_back( std::make_pair( "node1", "" ) );
data.push_back( std::make_pair( "node2", "" ) );
model->SetGroup( "Group 1", data );
data.push_back( std::make_pair( "node3", "" ) );
model->SetGroup( "Group 2", data );
treeView4->setModel( model );