Qt入门－QTreeWidget类

     QTreeWidget类是一个以树形显示数据的控件。

示例：

window.h

#ifndef __WINDOW_H__#define __WINDOW_H__#include <QMainWindow>#include <QLineEdit>#include <QLayout>#include <QLabel>#include <QTreeWidget>#include <QTreeWidgetItem>class Window : public QMainWindow{Q_OBJECTpublic:Window(QWidget *parent = NULL):QMainWindow(parent){tree = new QTreeWidget;tree->setColumnCount(1);tree->setHeaderLabel("Example");QTreeWidgetItem *note1 = new QTreeWidgetItem(QStringList("note1"));tree->addTopLevelItem(note1);QTreeWidgetItem *note2 = new QTreeWidgetItem(QStringList("note2"));tree->addTopLevelItem(note2);tree->expand(tree->model()->index(1, 0));QTreeWidgetItem *note3 = new QTreeWidgetItem(QStringList("note3"));tree->addTopLevelItem(note3);QTreeWidgetItem *childtree1 = new QTreeWidgetItem(QStringList("child1"));QTreeWidgetItem *childtree2 = new QTreeWidgetItem(QStringList("child2"));note2->addChild(childtree1);note2->addChild(childtree2);QHBoxLayout *leftLayout = new QHBoxLayout;leftLayout->addWidget(tree);QVBoxLayout *rightLayout = new QVBoxLayout;QLabel *lbl = new QLabel("select:");edt = new QLineEdit;rightLayout->addWidget(lbl);rightLayout->addWidget(edt);rightLayout->addStretch();QHBoxLayout *mainLayout = new QHBoxLayout;mainLayout->addLayout(leftLayout);mainLayout->addLayout(rightLayout);mainLayout->setStretch(0, 3);mainLayout->setStretch(1, 1);QWidget *mainWidget = new QWidget;mainWidget->setLayout(mainLayout);setCentralWidget(mainWidget);connect(tree, SIGNAL(clicked ( const QModelIndex &)), this, SLOT(clicked ( const QModelIndex &)));}private:QTreeWidget *tree;QLineEdit *edt;private slots:void clicked ( const QModelIndex & index ){edt->setText(tree->currentItem()->text(0));}};#endif

main.cpp

#include <QApplication>#include <QDialog>#include "Window.h"int main(int argc, char *argv[]){QApplication a(argc, argv);Window *mainWindow = new Window;mainWindow->resize(300, 160);mainWindow->setWindowTitle(QWidget::tr("Qt Test"));mainWindow->show();return a.exec();}

编译运行，界面如图：

代码说明：

(1)tree->setColumnCount(1); 设置树显示的列数。

(2)tree->setHeaderLabel("Example");设置树的每一列的显示标题。

(3)tree->addTopLevelItem(note1);追加一个顶层树节点。

(4)tree->expand(tree->model()->index(1, 0));展开第1行0列的节点。

(5)note2->addChild(childtree1);在节点note2下添加一个子节点childtree1。

(6)void clicked ( const QModelIndex & index );它是树单击事件。