QT notes - qtablewidget table spanning tree, qtreewidget tree node generates table content

Purpose ： We generate a tree from the data in the table , Then click the branch of the tree to get the data saved by the node on the tree and display it on another table .

A spanning tree table and data

The contents of the spanning tree are ：

By clicking on the node of the tree , Display the contents of the tree node ：

1. We need to generate a tree according to the contents of the table
1.1 Find the target string in a column

QList<QTableWidgetItem*> qtreewidgetTest::findItem(const QString& target, int column)
{
    
	// Store the string that finds the column 
	QList<QTableWidgetItem *> list;
	QString str;
	int row = ui.tableWidget2->rowCount();
	int col = ui.tableWidget2->columnCount();
	// Traverse the list   Find the target string 
	for (int i = 0; i < row; i++)
	{
    
		for (int j = 0; j < col;j++)
		{
    
			// If it is not this column 
			if(j != column)
				continue;
			// The string of this column is compared with the target character 
			str = ui.tableWidget2->item(i, j)->text();
			if (target == str)
			{
    
				list.push_back(ui.tableWidget2->item(i, j));
			}
		}
	}

	return  list;
}

1.2 Recurse all children of this parent node

void qtreewidgetTest::departTree(int fatherRow, QTreeWidgetItem* item)
{
    
	// What came in was his father's node 
	// Find his child node through the parent node 
	QList <QTableWidgetItem*> list;
	// Of the parent node ID Number 
	QString id = ui.tableWidget2->item(fatherRow, colItem)->text();
	// Find all the children under the father node 
	list = findItem(id, colItem2);

	int sonRow;
	QString name;
	if (!list.isEmpty())
	{
    
		for (int i = 0 ; i < list.size(); i++)
		{
    
			// The number of rows of the child and get the name of the child 
			sonRow = list.at(i)->row();
			name = ui.tableWidget2->item(sonRow, colItem1)->text();
			QTreeWidgetItem* newItem = new QTreeWidgetItem(item, QStringList(name));
			// Add it to the incoming parent node 
			item->addChild(item);
			// Recurse whether each child of the parent node has children 
			departTree(sonRow, newItem);
		}
	}
}

1.3 Make trees

void qtreewidgetTest::initTree()
{
    
	QList<QTableWidgetItem*> list;
	// If the parent node is 1  This node is the root node 
	QString str = "1";
	list = findItem(str, colItem2);
	int row;
	QString name;
	// The root node 
	if (!list.isEmpty()) 
	{
    
		for (int i = 0; i < list.size(); ++i) 
		{
    
			row = list.at(i)->row();
			name = ui.tableWidget2->item(row, colItem1)->text();
			QTreeWidgetItem* item = new QTreeWidgetItem(ui.treeWidget, QStringList(name));
			// Set the top-level node （ Root node ）
			ui.treeWidget->addTopLevelItem(item);
			// Recurse all child nodes of the parent node 
			departTree(row, item);
		}
	}
	ui.treeWidget->expandAll();

}

2. We need to give the tree node content , Then click the tree node to display the content in the table

	// Traverse the tree list 
	QTreeWidgetItemIterator it(ui.treeWidget);
	while (*it) 
	{
    
		if ((*it)->text(0) == QStringLiteral(" sales 1 Ministry "))
		{
    
			QVariant varData;
			varData.setValue(createMap(*it, list));
			(*it)->setData(0, Qt::UserRole, QVariant::fromValue(varData));
		}		
		else if ((*it)->text(0) == QStringLiteral(" The personnel department "))
		{
    
			QVariant varData1;
			varData1.setValue(createMap(*it, list1));
			(*it)->setData(0, Qt::UserRole, QVariant::fromValue(varData1));
		}

		//(*it)->text(0);
		++it;
	}

Click the tree node ：

// Definition SLOTS
public slots:
	void si_itemClicked(QTreeWidgetItem* item, int column);
// Connect click tree node signal 
	connect(ui.treeWidget, SIGNAL(itemClicked(QTreeWidgetItem* ,int)), this, SLOT(si_itemClicked(QTreeWidgetItem*, int)));
// stay SLOT Add data to the table 

Complete code ：

#pragma once

#include <QtWidgets/QWidget>
#include "ui_qtreewidgetTest.h"
#include <QTreeWidgetItem>
#include <QTableWidget>
#include <QStringList>
#include <QDebug>
#include <QStandardItem>
struct Person
{
    
	QString name;
	int age;
	int score;
	QString className;
};
Q_DECLARE_METATYPE(Person)
class qtreewidgetTest : public QWidget
{
    
	Q_OBJECT
	enum tableColumn
	{
    
		colItem = 0,
		colItem1 ,
		colItem2,
	};
public:
	qtreewidgetTest(QWidget *parent = Q_NULLPTR);
	~qtreewidgetTest();
	QMap <QString, QList<Person>> createMap(QTreeWidgetItem* item, QList<Person> & list);	// The name of the node of the current tree   Number   data 
	void init_TableWidget2();																// Initialization list 
	QList<QTableWidgetItem*> findItem(const QString& target, int column);					// Find the child of the current goal item
	void departTree(int row, QTreeWidgetItem* item);										// Update tree 
	void initTree();


public slots:
	void si_itemClicked(QTreeWidgetItem* item, int column);
private:
	Ui::qtreewidgetTestClass ui;

};

#include "qtreewidgetTest.h"

qtreewidgetTest::qtreewidgetTest(QWidget *parent)
	: QWidget(parent)
{
    
	ui.setupUi(this);
	init_TableWidget2();
	ui.treeWidget->setHeaderHidden(true);
	initTree();
	
	// Set data source 
	Person p = {
     QStringLiteral(" Xiao Song "),20,60,QStringLiteral("2 class ") };
	Person p1 = {
     QStringLiteral(" Wang Wu "),26,90,QStringLiteral("2 class ") };
	Person p2 = {
     QStringLiteral(" Xiao Ming "),24,70,QStringLiteral("1 class ") };
	Person p3 = {
     QStringLiteral(" petty thief "),30,50,QStringLiteral("4 class ") };

	// insert data 
	QList<Person> list;
	list.append(p);
	list.append(p1);
	list.append(p2);
	list.append(p3);


	Person p5 = {
     QStringLiteral(" Xiao Hu "),20,60,QStringLiteral("3 class ") };
	Person p6 = {
     QStringLiteral(" Xiao Chen "),26,90,QStringLiteral("2 class ") };
	Person p4 = {
     QStringLiteral(" Small Oh "),24,70,QStringLiteral("6 class ") };
	QList<Person> list1;
	list1.append(p4);
	list1.append(p5);
	list1.append(p6);

	// Traverse the tree list 
	QTreeWidgetItemIterator it(ui.treeWidget);
	while (*it) 
	{
    
		if ((*it)->text(0) == QStringLiteral(" sales 1 Ministry "))
		{
    
			QVariant varData;
			varData.setValue(createMap(*it, list));
			(*it)->setData(0, Qt::UserRole, QVariant::fromValue(varData));
		}		
		else if ((*it)->text(0) == QStringLiteral(" The personnel department "))
		{
    
			QVariant varData1;
			varData1.setValue(createMap(*it, list1));
			(*it)->setData(0, Qt::UserRole, QVariant::fromValue(varData1));
		}

		//(*it)->text(0);
		++it;
	}


	// Set table properties 
	ui.tableWidget1->setColumnCount(4);
	ui.tableWidget1->verticalHeader()->hide();
	ui.tableWidget1->setEditTriggers(QAbstractItemView::NoEditTriggers);
	ui.tableWidget1->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);

	// Set the header 
	QStringList head;
	head << QStringLiteral(" full name ") << QStringLiteral(" Age ") << QStringLiteral(" fraction ") << QStringLiteral(" class ");
	ui.tableWidget1->setHorizontalHeaderLabels(head);

	connect(ui.treeWidget, SIGNAL(itemClicked(QTreeWidgetItem* ,int)), this, SLOT(si_itemClicked(QTreeWidgetItem*, int)));
}

qtreewidgetTest::~qtreewidgetTest()
{
    

}


QMap<QString, QList<Person>> qtreewidgetTest::createMap(QTreeWidgetItem * item, QList<Person>& p)
{
    
	QMap <QString, QList<Person>> list;
	list.insert(item->text(0), p);

	return list;

}

void qtreewidgetTest::init_TableWidget2()
{
    
	ui.tableWidget2->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);	// Horizontal table adaptation 
	ui.tableWidget2->setEditTriggers(QAbstractItemView::NoEditTriggers);

	QStringList tab2List;
	tab2List << "ID" << QStringLiteral(" name ") << "parent_ID";
	ui.tableWidget2->setHorizontalHeaderLabels(tab2List);
}

QList<QTableWidgetItem*> qtreewidgetTest::findItem(const QString& target, int column)
{
    
	// Store the string that finds the column 
	QList<QTableWidgetItem *> list;
	QString str;
	int row = ui.tableWidget2->rowCount();
	int col = ui.tableWidget2->columnCount();
	// Traverse the list   Find the target string 
	for (int i = 0; i < row; i++)
	{
    
		for (int j = 0; j < col;j++)
		{
    
			// If it is not this column 
			if(j != column)
				continue;
			// The string of this column is compared with the target character 
			str = ui.tableWidget2->item(i, j)->text();
			if (target == str)
			{
    
				list.push_back(ui.tableWidget2->item(i, j));
			}
		}
	}

	return  list;
}

void qtreewidgetTest::departTree(int fatherRow, QTreeWidgetItem* item)
{
    
	// What came in was his father's node 
	// Find his child node through the parent node 
	QList <QTableWidgetItem*> list;
	// Of the parent node ID Number 
	QString id = ui.tableWidget2->item(fatherRow, colItem)->text();
	// Find all the children under the father node 
	list = findItem(id, colItem2);

	int sonRow;
	QString name;
	if (!list.isEmpty())
	{
    
		for (int i = 0 ; i < list.size(); i++)
		{
    
			// The number of rows of the child   Get the child's name 
			sonRow = list.at(i)->row();
			name = ui.tableWidget2->item(sonRow, colItem1)->text();
			QTreeWidgetItem* newItem = new QTreeWidgetItem(item, QStringList(name));
			item->addChild(item);
			departTree(sonRow, newItem);
		}
	}
}

void qtreewidgetTest::initTree()
{
    
	QList<QTableWidgetItem*> list;
	// If the parent node is 1  This node is the root node 
	QString str = "1";
	list = findItem(str, colItem2);
	int row;
	QString name;
	// The root node 
	if (!list.isEmpty()) 
	{
    
		for (int i = 0; i < list.size(); ++i) 
		{
    
			row = list.at(i)->row();
			name = ui.tableWidget2->item(row, colItem1)->text();
			QTreeWidgetItem* item = new QTreeWidgetItem(ui.treeWidget, QStringList(name));
			// Set the grading node 
			ui.treeWidget->addTopLevelItem(item);
			departTree(row, item);
		}
	}
	ui.treeWidget->expandAll();
}

void qtreewidgetTest::si_itemClicked(QTreeWidgetItem* item, int column)
{
    
	// clear list 
	ui.tableWidget1->clearContents();
	int rowNum = ui.tableWidget1->rowCount();
	qDebug() << rowNum;
	// Number of rows removed 
	for (int i = rowNum - 1; i >= 0; i--)
	{
    
		ui.tableWidget1->removeRow(i);
	}
	if (item == NULL)
		return;
	QMap <QString, QList<Person>> list = item->data(0, Qt::UserRole).value<QMap <QString, QList<Person>> >();
	for (auto iter = list.begin(); iter != list.end(); ++iter)
	{
    
		const QList<Person>& plist = iter.value();
		const QString &text = iter.key();
		int row = plist.size();
		// Insert rows 
		ui.tableWidget1->setRowCount(row);
		// Insert table data 
		for (int i = 0; i < row; i++)
		{
    
			ui.tableWidget1->setItem(i, 0, new QTableWidgetItem(plist.at(i).name));
			ui.tableWidget1->setItem(i, 1, new QTableWidgetItem(QString::number(plist.at(i).age)));
			ui.tableWidget1->setItem(i, 2, new QTableWidgetItem(QString::number(plist.at(i).score)));
			ui.tableWidget1->setItem(i, 3, new QTableWidgetItem(plist.at(i).className));
		}
	}
	qDebug() << item->text(0);
}

ui chart ：

design sketch ：

Refer to the connection ：
https://blog.csdn.net/weixin_45465612/article/details/104530127
https://ask.csdn.net/questions/1063721