Qt QGraphicsScene绘图节点保存及恢复

在上一篇文章中 Qt 遍历不规则树的节点，介绍了节点保存及恢复，但是恢复时不是将原有节点原样恢复。这里介绍怎样恢复原样。

思路：要恢复恢复，首先肯定要有节点的坐标（在scene中）。节点恢复后，还要使用箭头连接。据此，我们保存时，要保存节点坐标，及箭头首尾节点。根据上一篇文章，我们在创建时已经给节点了唯一标识。

唯一标识代码：

?

1 2 3 4 5 6

QString getGUID() {     QUuid id = QUuid::createUuid();     QString strId = id.toString();     return strId; }

保存函数及说明如下：

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

bool OperateItemFile::SaveItemArrowFile(QList<DiagramItem *> &pItemList, QList<Arrow *> &pArrowList, QString itFilePath) {     if(pItemList.size() > 0){         QDomDocument doc;         doc.appendChild( doc.createProcessingInstruction("xml", XML_HEAD_INFO));         QFile file(itFilePath);         if (!file.open(QIODevice::WriteOnly)){             return false;         }         QDomElement root = doc.createElement("Root");         doc.appendChild(root);         //设备节点         QDomElement dev = doc.createElement("DeviceVerb");         root.appendChild(dev);         for(int i=0 ;i<pItemList.size() ;i++){             QDomElement ItemE = doc.createElement("Device");             ItemE.setAttribute("ItemId" ,pItemList.at(i)->getItemId());             ItemE.setAttribute("left" ,pItemList.at(i)->boundingRect().left());             ItemE.setAttribute("top" ,pItemList.at(i)->boundingRect().top());             ItemE.setAttribute("right" ,pItemList.at(i)->boundingRect().right());             ItemE.setAttribute("bottom" ,pItemList.at(i)->boundingRect().bottom());             ItemE.setAttribute("name" ,pItemList.at(i)->getText());             ItemE.setAttribute("x" ,pItemList.at(i)->pos().x());             ItemE.setAttribute("y" ,pItemList.at(i)->pos().y());             ItemE.setAttribute("z" ,pItemList.at(i)->zValue());             ItemE.setAttribute("color" ,pItemList.at(i)->brush().color().rgb());             ItemE.setAttribute("brushstyle" ,pItemList.at(i)->brush().style());             ItemE.setAttribute("type" ,pItemList.at(i)->diagramType());             getItemChild(pItemList, pItemList.at(i), doc, ItemE);             dev.appendChild(ItemE);         }           //保存箭头         if(pArrowList.size() > 0){             QDomElement arrow = doc.createElement("ArrowVerb");             root.appendChild(arrow);             for(int i=0 ;i<pArrowList.size() ;i++){                 QDomElement ArrowItem = doc.createElement("Arrow");                 ArrowItem.setAttribute("StartItemId" ,pArrowList.at(i)->getStartId());                 ArrowItem.setAttribute("EndItemId" ,pArrowList.at(i)->getEndId());                 arrow.appendChild(ArrowItem);             }         }           QString xml = doc.toString();         QTextStream txtOutput(&file);         txtOutput.setCodec("UTF-8");         txtOutput<<xml;         file.close();     }     return true; }

　　函数中的参数依次是：所有节点，所有箭头，及保存的文件名。

恢复函数如下：

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143

bool OperateItemFile::getNormalItem(QString itemType, QList<DiagramItem *> *pList, QDomNodeList &domList, QMenu *itemMenu)<br>{     for (int i = 0; i < domList.size(); i++) {         QStringList szAttrVal;         QDomElement fileElem = domList.at(i).toElement();         QString l = fileElem.attribute("left");         QString t = fileElem.attribute("top");         QString r = fileElem.attribute("right");         QString b = fileElem.attribute("bottom");         QString name = fileElem.attribute("name");         QString id = fileElem.attribute("ItemId");         QString x = fileElem.attribute("x");         QString y = fileElem.attribute("y");         QString z = fileElem.attribute("z");         QString type = fileElem.attribute("type");         QString rgb = fileElem.attribute("color");         QString brushstyle = fileElem.attribute("brushstyle");           DiagramItem* pItem = new DiagramItem((DiagramItem::DiagramType)type.toUInt() ,itemMenu);         pItem->setPos(QPointF(x.toFloat() ,y.toFloat()));         pItem->setZValue(z.toFloat());         pItem->setBkColor(QColor(rgb.toUInt()));         pItem->setItemId(id);         pItem->setText(name);         pItem->setBrush(QBrush(rgb.toUInt(),  (Qt::BrushStyle)brushstyle.toUInt()));         if(itemType.compare("Port") == 0)         {             QString parentItemId = fileElem.attribute("parentItemId");             pItem->setParentItemId(parentItemId);         }         szAttrVal.push_back(name);         szAttrVal.push_back(rgb);         szAttrVal.push_back("False");         szAttrVal.push_back("");         szAttrVal.push_back("");         szAttrVal.push_back("");         szAttrVal.push_back("");         for (int j = 0; j < szAttrName.size(); j++) {             pItem->setItemAttr(j, szAttrName.at(j), szAttrVal.at(j));         }           pList->push_back(pItem);     }     return true; }   bool OperateItemFile::GetItemArrowFromFile(QString strItemPath, QList<DiagramItem *> *pItemList, QList<Arrow *> *pArrowList, QMenu *itemMenu)<br>{     if(strItemPath.length() <= 0 || pItemList == NULL || pArrowList == NULL)         return false;       QDomDocument doc;     QFile file(strItemPath);     if (!file.open(QIODevice::ReadOnly)){         return false;     }     if (!doc.setContent(&file))     {         file.close();         return false;     }     QDomNodeList listNormalItem = doc.elementsByTagName("Device");     QDomNodeList listPortItem = doc.elementsByTagName("Port");     QDomNodeList listArrow = doc.elementsByTagName("Arrow");       getNormalItem("Item", pItemList, listNormalItem, itemMenu);     getNormalItem("Port", pItemList, listPortItem, itemMenu);       for (int i = 0; i < listArrow.size(); i++) {         QDomElement arrowEle = listArrow.at(i).toElement();         QString sid = arrowEle.attribute("StartItemId");         QString eid = arrowEle.attribute("EndItemId");         Arrow* pItem = new Arrow(NULL ,NULL);         pItem->setItemId(sid,eid);         pArrowList->push_back(pItem);     }       file.close();     return true; }   bool OperateItemFile::loadItemToScene(DiagramScene* pScene, bool bIsDialog, QString srcPath)<br>{     if(!pScene) return false;       QList<DiagramItem*> itemList;     QList<Arrow*> ArrowList;       QString strName;     if(bIsDialog)         strName = QFileDialog::getOpenFileName(nullptr, QObject::tr("open xml file"), p_globalObject->ProjectPath() + "/" + p_globalObject->getProjectName() ,QObject::tr("XML文件(*XML*)"));     else         strName = srcPath;       ////////////////////////////////////////////////////////////////////////////////////     if(!GetItemArrowFromFile(srcPath, &itemList, &ArrowList, NULL))         return false;           pScene->ItemClear();           int i=0;         for(i=0 ;i<itemList.size() ;i++){             //itemList.at(i)->setBrush(pScene->itemColor());             pScene->addItem(itemList.at(i));         }         pScene->setMode(DiagramScene::Mode::MoveItem);           //设置箭头起始节点         int j=0;         for(i=0 ;i<ArrowList.size(); i++){             for(j=0 ;j<itemList.size() ;j++){                 if(ArrowList.at(i)->getStartId() == itemList.at(j)->getItemId()){                     ArrowList.at(i)->setStartItem(itemList.at(j));                     break;                 }             }         }         //设置箭头结尾节点         for(i=0 ;i<ArrowList.size(); i++){             for(j=0 ;j<itemList.size() ;j++){                 if(ArrowList.at(i)->getEndId() == itemList.at(j)->getItemId()){                     ArrowList.at(i)->setEndItem(itemList.at(j));                     break;                 }             }         }           for(i=0 ;i<ArrowList.size() ;i++){             if(ArrowList.at(i)->startItem()!=NULL)                 ArrowList.at(i)->startItem()->addArrow(ArrowList.at(i));               if(ArrowList.at(i)->endItem()!=NULL)                 ArrowList.at(i)->endItem()->addArrow(ArrowList.at(i));               ArrowList.at(i)->setColor(pScene->lineColor());             ArrowList.at(i)->setZValue(-1000.0);             pScene->addItem(ArrowList.at(i));             if(p_globalObject->getCurStatus() == QGlobalObject::devStatus)                 ArrowList.at(i)->setArrowFlag(true);             else                 ArrowList.at(i)->setArrowFlag(true);             ArrowList.at(i)->updatePosition();         }       return true; }

　　

?

1	getNormalItem函数中的type，区分是不是子节点。loadItemToScene 的参数bIsDialog,来确定是否显示文件对话框。

 

Qt 遍历不规则树的节点