创建具有复选框的树型控件

本文章介绍如何创建具有复选框的树型控件。    描述：当选中group1节点时，它的子节点会全部选中；当取消选择group1节点时，它的子节点的选中状态会全部被取消；而选中子节点时，父节点显示部分选中状态。源码：widge.h

#ifndef WIDGET_H

#define WIDGET_H

#include <QWidget>

#include <QTreeWidgetItem>

#include <QGridLayout>

namespace Ui {

class Widget;

}

class Widget : public QWidget

{

Q_OBJECT

public:

explicit Widget(QWidget *parent = 0);

~Widget();

void init();

void updateParentItem(QTreeWidgetItem *item);

public slots:

void treeItemChanged(QTreeWidgetItem *item, int colum);

private:

Ui::Widget *ui;

QTreeWidget *treeWidget;

QGridLayout *gridLayout;

};

#endif // WIDGET_H

源码：widget.cpp

#include "widget.h"

#include "ui_widget.h"

#include <QTreeWidget>

#include <QDebug>

Widget::Widget(QWidget *parent) :

QWidget(parent),

ui(new Ui::Widget)

{

ui->setupUi(this);

treeWidget = new QTreeWidget(this);

treeWidget->setHeaderLabel(tr("全选|部分选中|未选"));

gridLayout = new QGridLayout(this);

gridLayout->addWidget(treeWidget);

init();

connect(treeWidget, &QTreeWidget::itemChanged, this, &Widget::treeItemChanged); // qt5

//    connect(treeWidget, SIGNAL(itemChanged(QTreeWidgetItem*, int)), this, SLOT(treeItemChanged(QTreeWidgetItem*, int))); // qt4

}

Widget::~Widget()

{

delete ui;

}

void Widget::init()

{

treeWidget->clear();

QTreeWidgetItem *group1 = new QTreeWidgetItem(treeWidget);

group1->setText(0, "group1");

group1->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

group1->setCheckState(0, Qt::Unchecked);

QTreeWidgetItem *subItem11 = new QTreeWidgetItem(group1);

subItem11->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

subItem11->setText(0, "subItem11");

subItem11->setCheckState(0, Qt::Unchecked);

QTreeWidgetItem *subItem12 = new QTreeWidgetItem(group1);

subItem12->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

subItem12->setText(0, "subItem12");

subItem12->setCheckState(0, Qt::Unchecked);

QTreeWidgetItem *subItem13 = new QTreeWidgetItem(group1);

subItem13->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

subItem13->setText(0, "subItem13");

subItem13->setCheckState(0, Qt::Unchecked);

QTreeWidgetItem *subItem14 = new QTreeWidgetItem(group1);

subItem14->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

subItem14->setText(0, "subItem14");

subItem14->setCheckState(0, Qt::Unchecked);

QTreeWidgetItem *group2 = new QTreeWidgetItem(treeWidget);

group2->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

group2->setText(0, "group2");

group2->setCheckState(0, Qt::Unchecked);

QTreeWidgetItem *subItem21 = new QTreeWidgetItem(group2);

subItem21->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

subItem21->setText(0, "subItem21");

subItem21->setCheckState(0, Qt::Unchecked);

QTreeWidgetItem *subItem22 = new QTreeWidgetItem(group2);

subItem22->setFlags(Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable);

subItem22->setText(0, "subItem22");

subItem22->setCheckState(0, Qt::Unchecked);

}

void Widget::treeItemChanged(QTreeWidgetItem *item, int colum)

{

QString itemText = item->text(0);

qDebug() << itemText;

// select

if(Qt::Checked == item->checkState(0)){

QTreeWidgetItem *parent = item->parent();

int count = item->childCount();

if(count > 0){

for(int i = 0; i < count; i++){

            // select subItem

item->child(i)->setCheckState(0, Qt::Checked);

}

}else{

// subItem

updateParentItem(item);

}

}else if(Qt::Unchecked == item->checkState(0)){

int count = item->childCount();

if(count > 0){

for(int i = 0; i < count; i++){

item->child(i)->setCheckState(0, Qt::Unchecked);

}

}else{

// subItem

updateParentItem(item);

}

}

}

void Widget::updateParentItem(QTreeWidgetItem *item)

{

QTreeWidgetItem *parent = item->parent();

if(parent == NULL){

return;

}

// select subItem count

int selectedCount = 0;

int childCount = parent->childCount();

for(int i = 0; i < childCount; i++){

QTreeWidgetItem *childItem = parent->child(i);

if(childItem->checkState(0) == Qt::Checked)

selectedCount++;

}

if(selectedCount <= 0)

parent->setCheckState(0, Qt::Unchecked);

else if(selectedCount > 0 && selectedCount < childCount)

parent->setCheckState(0, Qt::PartiallyChecked); // select some

else if(selectedCount == childCount)

parent->setCheckState(0, Qt::Checked);

}

效果如下：案例源码以上传到：http://download.csdn.net/detail/qq_33218979/9905506