如何给QTreeView的节点显示图标

一 树形结构体定义 treeitemh

Cpp代码

/

@brief 通用树形结构类

/

class TreeItem

{

public:

TreeItem(const QList<QVariant> &data,TreeItem parent=0 );

~TreeItem();

void appendChild(TreeItem child);

TreeItem child(int row);

int childCount() const;

int columnCount() const;

QVariant data(int column) const;

int row() const;

TreeItem parent();

private:

TreeItem parentItem; // 父结点

QList<TreeItem> childItems; // 子结点列表

QList<QVariant> itemData; // 子节点对应数据

};

二 树形model实现

Cpp代码

#include <QAbstractItemModel>

#include "TreeItemh"

class TagTreeModel : public QAbstractItemModel

{

Q_OBJECT

public:

TagTreeModel(QObject parent = 0);

~TagTreeModel();

QVariant data(const QModelIndex &index, int role) const;

Qt::ItemFlags flags(const QModelIndex &index) const;

QVariant headerData(int section, Qt::Orientation orientation,

int role = Qt::DisplayRole) const;

QModelIndex index(int row, int column,

const QModelIndex &parent = QModelIndex()) const;

QModelIndex parent(const QModelIndex &index) const;

int rowCount(const QModelIndex &parent = QModelIndex()) const;

int columnCount(const QModelIndex &parent = QModelIndex()) const;

// 构建模型数据

void setupModelData(TreeItem parent);

// 更新模型数据

void updateData();

private:

TreeItem rootItem; // 最顶层顶根节点(一个无效的QModelIndex)

};

TagTreeModelcpp

Cpp代码

#include "TagTreeModelh"

#include <QtGui>

TagTreeModel::TagTreeModel(QObject parent):QAbstractItemModel(parent)

{

rootItem=NULL;

updateData();

}

TagTreeModel::~TagTreeModel()

{

delete rootItem;

}

void TagTreeModel::updateData()

{

// 废弃旧的模型数据

if(rootItem)

{

delete rootItem;

rootItem=NULL;

}

QList<QVariant> rootData;

rootData<<"Tag"<<"Type";

rootItem=new TreeItem(rootData);

setupModelData(rootItem);

// 刷新模型

reset();

}

QVariant TagTreeModel::data(const QModelIndex &index, int role) const

{

if (!indexisValid())

return QVariant();

// 添加图标

if(role==Qt::DecorationRole&&indexcolumn()==0)

return QIcon("images/foldpng");

// 显示节点数据值

if(role==Qt::DisplayRole)

{

TreeItem item=static_cast<TreeItem>(indexinternalPointer());

return item->data(indexcolumn());

}

return QVariant();

}

Qt::ItemFlags TagTreeModel::flags(const QModelIndex &index) const

{

if(!indexisValid())

return 0;

return Qt::ItemIsEnabled|Qt::ItemIsSelectable;

}

QVariant TagTreeModel::headerData(int section, Qt::Orientation orientation,int role) const

{

if(orientation==Qt::Horizontal&&role==Qt::DisplayRole)

return rootItem->data(section);

return QVariant();

}

QModelIndex TagTreeModel::index(int row, int column,const QModelIndex &parent) const

{

if(!hasIndex(row,column,parent))

return QModelIndex();

TreeItem parentItem;

if(!parentisValid())

{

parentItem=rootItem;

}else

{

parentItem=static_cast<TreeItem>(parentinternalPointer());

}

TreeItem childItem=parentItem->child(row);

if(childItem)

return createIndex(row,column,childItem); // 展开树形,为子节点建立索引

else

return QModelIndex();

}

QModelIndex TagTreeModel::parent(const QModelIndex &index) const

{

if(!indexisValid())

return QModelIndex();

TreeItem childItem=static_cast<TreeItem>(indexinternalPointer());

TreeItem parentItem=childItem->parent();

// 顶层节点,直接返回空索引

if(parentItem==rootItem)

return QModelIndex();

// 为父结点建立索引

return createIndex(parentItem->row(),0,parentItem);

}

int TagTreeModel::rowCount(const QModelIndex &parent) const

{

TreeItem parentItem;

if(!parentisValid())

parentItem=rootItem;

else

parentItem=static_cast<TreeItem>(parentinternalPointer());

return parentItem->childCount(); // 返回父结点下子结点数目

}

int TagTreeModel::columnCount(const QModelIndex &parent ) const

{

return rootItem->columnCount();

}

// 设置模型数据,构建包含10个根结点,每个根结点包含两个子节点的树形结构

void TagTreeModel::setupModelData(TreeItem parent)

{

for(int i=0;i<10;i++)

{

QList<QVariant> datas;

datas<<QString("设备-%1")arg(i+1)<<QString("类型-%1")arg(i+1);

// 主结点下挂两个子节点

TreeItem primary=new TreeItem(datas,parent);

parent->appendChild(primary);

for(int j=0;j<2;j++)

{

QList<QVariant> ds;

ds<<QString("子设备-%1")arg(j+1)<<QString("子类型-%1")arg(j+1);

primary->appendChild(new TreeItem(ds,primary));

}

}

}

void QAbstractItemView::setModel(QAbstractItemModel model)

{

    Q_D(QAbstractItemView);

    if (model == d->model)

        return;

    if (d->model && d->model != QAbstractItemModelPrivate::staticEmptyModel()) {

        disconnect(d->model, SIGNAL(destroyed()),

                   this, SLOT(_q_modelDestroyed()));

        disconnect(d->model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),

                   this, SLOT(dataChanged(QModelIndex,QModelIndex)));

        disconnect(d->model, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),

                   this, SLOT(_q_headerDataChanged()));

        disconnect(d->model, SIGNAL(rowsInserted(QModelIndex,int,int)),

                   this, SLOT(rowsInserted(QModelIndex,int,int)));

        disconnect(d->model, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),

                   this, SLOT(rowsAboutToBeRemoved(QModelIndex,int,int)));

        disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),

                   this, SLOT(_q_rowsRemoved(QModelIndex,int,int)));

        disconnect(d->model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),

                   this, SLOT(_q_columnsAboutToBeRemoved(QModelIndex,int,int)));

        disconnect(d->model, SIGNAL(columnsRemoved(QModelIndex,int,int)),

                   this, SLOT(_q_columnsRemoved(QModelIndex,int,int)));

        disconnect(d->model, SIGNAL(columnsInserted(QModelIndex,int,int)),

                   this, SLOT(_q_columnsInserted(QModelIndex,int,int)));

        disconnect(d->model, SIGNAL(modelReset()), this, SLOT(reset()));

        disconnect(d->model, SIGNAL(layoutChanged()), this, SLOT(_q_layoutChanged()));

    }

    d->model = (model  model : QAbstractItemModelPrivate::staticEmptyModel());

    // These asserts do basic sanity checking of the model

    Q_ASSERT_X(d->model->index(0,0) == d->model->index(0,0),

               "QAbstractItemView::setModel",

               "A model should return the exact same index "

               "(including its internal id/pointer) when asked for it twice in a row");

    Q_ASSERT_X(d->model->index(0,0)parent() == QModelIndex(),

               "QAbstractItemView::setModel",

               "The parent of a top level index should be invalid");

    if (d->model != QAbstractItemModelPrivate::staticEmptyModel()) {

        connect(d->model, SIGNAL(destroyed()),

                this, SLOT(_q_modelDestroyed()));

        connect(d->model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),

                this, SLOT(dataChanged(QModelIndex,QModelIndex)));

        connect(d->model, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),

                this, SLOT(_q_headerDataChanged()));

        connect(d->model, SIGNAL(rowsInserted(QModelIndex,int,int)),

                this, SLOT(rowsInserted(QModelIndex,int,int)));

        connect(d->model, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),

                this, SLOT(rowsAboutToBeRemoved(QModelIndex,int,int)));

        connect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),

                this, SLOT(_q_rowsRemoved(QModelIndex,int,int)));

        connect(d->model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),

                this, SLOT(_q_columnsAboutToBeRemoved(QModelIndex,int,int)));

        connect(d->model, SIGNAL(columnsRemoved(QModelIndex,int,int)),

                this, SLOT(_q_columnsRemoved(QModelIndex,int,int)));

        connect(d->model, SIGNAL(columnsInserted(QModelIndex,int,int)),

                this, SLOT(_q_columnsInserted(QModelIndex,int,int)));

        connect(d->model, SIGNAL(modelReset()), this, SLOT(reset()));

        connect(d->model, SIGNAL(layoutChanged()), this, SLOT(_q_layoutChanged()));

    }

<span style="color: #FF0000;">

    QItemSelectionModel selection_model = new QItemSelectionModel(d->model, this);

</span>

//这个TMD 怎么控制啊，大爷的，每次set 都来一个，我还没看到那边进行处理的。

//但可以肯定的是不断的setModel 我感觉100% 内存泄露

    connect(d->model, SIGNAL(destroyed()), selection_model, SLOT(deleteLater()));

    setSelectionModel(selection_model);

    reset(); // kill editors, set new root and do layout

}

这个需要重写一些model的方法

当然你需要编辑也要实现自己的delegate

class MyTableDelgate : public QStyledItemDelegate

{

Q_OBJECT

public:

explicit MyTableDelgate(QObject parent = 0);

protected:

//basic function for a read-only delegate, you can draw anything with the painter

void paint(QPainter painter, const QStyleOptionViewItem &option, const QModelIndex &index) const;

QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const;

//edit 5 function

QWidget createEditor(QWidget parent, const QStyleOptionViewItem &option, const QModelIndex &index) const;

void setEditorData(QWidget editor, const QModelIndex &index) const;

void setModelData(QWidget editor, QAbstractItemModel model, const QModelIndex &index) const;

void updateEditorGeometry ( QWidget editor, const QStyleOptionViewItem & option, const QModelIndex & index ) const;

private:

QLineEdit m_LineEdit;

};

model

class MyTableDelgate : public QStyledItemDelegate

{

Q_OBJECT

public:

explicit MyTableDelgate(QObject parent = 0);

protected:

//basic function for a read-only delegate, you can draw anything with the painter

void paint(QPainter painter, const QStyleOptionViewItem &option, const QModelIndex &index) const;

QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const;

//edit 5 function

QWidget createEditor(QWidget parent, const QStyleOptionViewItem &option, const QModelIndex &index) const;

void setEditorData(QWidget editor, const QModelIndex &index) const;

void setModelData(QWidget editor, QAbstractItemModel model, const QModelIndex &index) const;

void updateEditorGeometry ( QWidget editor, const QStyleOptionViewItem & option, const QModelIndex & index ) const;

};

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