qt绘制网络拓补图(连接数据库，无限绘制，可拖动节点）

#include <QtWidgets> #include "nodeframe.h" #include <iostream> using namespace std; NodeFrame::NodeFrame(QWidget *parent) : QGraphicsView(parent) { setGeometry(0,0,1920,2000); m_scene = new QGraphicsScene(0, 0, this->width(), this->height()); this->setScene(m_scene); QScrollBar *horBar = this->horizontalScrollBar(); QScrollBar *verBar = this->verticalScrollBar(); horBar->setValue(horBar->maximum()); verBar->setValue(verBar->maximum()); // connectSqlServer();//连接数据库并读取数据,这里先禁用，如果你配好了数据库，则可以开起来 manulInitNoteList();//如果不连接数据库则可以手动初始化节点队列，连接数据库的情况下，这行要禁用！ initNodeList(); } void NodeFrame::manulInitNoteList() { NodeInSql node; node.nNodeID =1; node.nParentID =1; node.strNodeName ="根节点"; m_lstNodeInSql.append(node); node.nNodeID =2; node.nParentID =1; node.strNodeName ="子节点2"; m_lstNodeInSql.append(node); node.nNodeID =3; node.nParentID =1; node.strNodeName ="子节点3"; m_lstNodeInSql.append(node); node.nNodeID =4; node.nParentID =1; node.strNodeName ="子节点4"; m_lstNodeInSql.append(node); node.nNodeID =5; node.nParentID =1; node.strNodeName ="子节点5"; m_lstNodeInSql.append(node); node.nNodeID =6; node.nParentID =2; node.strNodeName ="子节点6"; m_lstNodeInSql.append(node); node.nNodeID =7; node.nParentID =2; node.strNodeName ="子节点7"; m_lstNodeInSql.append(node); node.nNodeID =8; node.nParentID =3; node.strNodeName ="子节点8"; m_lstNodeInSql.append(node); node.nNodeID =9; node.nParentID =3; node.strNodeName ="子节点9"; m_lstNodeInSql.append(node); node.nNodeID =10; node.nParentID =4; node.strNodeName ="子节点10"; m_lstNodeInSql.append(node); node.nNodeID =11; node.nParentID =10; node.strNodeName ="子节点11"; m_lstNodeInSql.append(node); node.nNodeID =12; node.nParentID =11; node.strNodeName ="子节点12"; m_lstNodeInSql.append(node); node.nNodeID =13; node.nParentID =12; node.strNodeName ="子节点13"; m_lstNodeInSql.append(node); node.nNodeID =14; node.nParentID =13; node.strNodeName ="子节点14"; m_lstNodeInSql.append(node); node.nNodeID =15; node.nParentID =13; node.strNodeName ="子节点15"; m_lstNodeInSql.append(node); node.nNodeID =16; node.nParentID =13; node.strNodeName ="子节点16"; m_lstNodeInSql.append(node); node.nNodeID =17; node.nParentID =13; node.strNodeName ="子节点17"; m_lstNodeInSql.append(node); node.nNodeID =18; node.nParentID =13; node.strNodeName ="子节点18"; m_lstNodeInSql.append(node); } NodeFrame::~NodeFrame() { delete m_scene; } void NodeFrame::refresh() { this->destroyed(m_scene); m_scene = new QGraphicsScene(0, 0, this->width(), this->height()); this->setScene(m_scene); initNodeList(); } void NodeFrame::connectSqlServer() { QSqlDatabase db= QSqlDatabase::addDatabase("QODBC", "dbTemp"); db.setDatabaseName(QString("DRIVER={SQL SERVER};" "SERVER=%1;" //服务器名称 "DATABASE=%2;"//数据库名 "UID=%3;" //登录名 "PWD=%4;" //密码 ).arg("127.0.0.1,49674")//我电脑上的端口号是49674 .arg("myTestSql") .arg("Bruce") .arg("Qwerty*963.-+") ); //数据库连接 bool ok = db.open(); if(ok) { qDebug()<<"database open success"; } else { qDebug()<<db.lastError(); return; } //数据库查询 QSqlQuery query(db); query.exec("SELECT * FROM Node;"); while(query.next()) { NodeInSql node; if(query.value(1).isValid()) node.nNodeID = query.value(1).toInt(); if(query.value(2).isValid()) node.nParentID = query.value(2).toInt(); if(query.value(3).isValid()) node.strNodeName = query.value(3).toString(); m_lstNodeInSql.append(node); } db.close(); } void NodeFrame::initNodeList() { //找到根节点 NodeInSql nRootID; foreach(NodeInSql node,m_lstNodeInSql) { if(node.nNodeID==node.nParentID) { nRootID = node; } } NodeInfoToShow rootNodeInfoToShow; rootNodeInfoToShow.nLevel = 0; rootNodeInfoToShow.nNodeID = nRootID.nNodeID; rootNodeInfoToShow.nParentID = nRootID.nParentID; rootNodeInfoToShow.ptPos = QPoint(0,100); rootNodeInfoToShow.strNodeName = nRootID.strNodeName; m_lstNodeInfoToShow.append(rootNodeInfoToShow); NetNode *rootNetNode = new NetNode(rootNodeInfoToShow,m_scene); parseNodesInSql(rootNodeInfoToShow,rootNetNode);//解析所有节点关系及位置 } void NodeFrame::parseNodesInSql(NodeInfoToShow node,NetNode *netNode) { int nChildNum = 0;//当前node节点有几个子节点 int nWidth = node.nLevel%2==0?250:150;//节点之间的横向间隔 int nHeight = 200;//节点之间的纵向间隔 QList<NodeInfoToShow> lstNodeInCrtLevel;//当前node下的所有节点 for(int i = 0;i<m_lstNodeInSql.count();i++) { if(m_lstNodeInSql[i].nParentID==node.nNodeID && m_lstNodeInSql[i].nParentID!=m_lstNodeInSql[i].nNodeID) { nChildNum++; NodeInfoToShow rootNodeInfoToShow; rootNodeInfoToShow.nLevel = node.nLevel+1; rootNodeInfoToShow.nNodeID = m_lstNodeInSql[i].nNodeID; rootNodeInfoToShow.nParentID = node.nNodeID; rootNodeInfoToShow.ptPos = QPoint(0,0);//这里先给0，0点作为初始值，下面再给每个子节点确定位置 rootNodeInfoToShow.strNodeName = m_lstNodeInSql[i].strNodeName; lstNodeInCrtLevel.append(rootNodeInfoToShow); } } //确定每个子节点的位置 for(int i = 0;i<lstNodeInCrtLevel.count();i++) { if(nChildNum%2==1)//有奇数个子节点 { int nHalf = (nChildNum-1)/2; int nX =node.ptPos.x()+(i-nHalf)*nWidth;//以上一个节点的x坐标为基础加上偏移量 int nY = node.ptPos.y()+nHeight;//以上一个节点的y坐标为基础加上偏移量 lstNodeInCrtLevel[i].ptPos = QPoint(nX,nY); } else//有偶数个子节点 { int nHalf = nChildNum/2; int nX =node.ptPos.x()+(i-nHalf)*nWidth+nWidth/2;//以上一个节点的x坐标为基础加上偏移量 int nY = node.ptPos.y()+nHeight;//以上一个节点的y坐标为基础加上偏移量 lstNodeInCrtLevel[i].ptPos = QPoint(nX,nY); } m_lstNodeInfoToShow.append(lstNodeInCrtLevel[i]); NetNode *subNetNode = new NetNode(lstNodeInCrtLevel[i],m_scene); NodeLink *link = new NodeLink(netNode, subNetNode); if (link) { m_scene->addItem(link); } parseNodesInSql(lstNodeInCrtLevel[i],subNetNode); } }