QT实现校园导航

导航是地图类项目实战中经常会遇到了。看上去貌似没头绪，其实是有模板遵循的。我们直接根据图看代码。

//MainWidget.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "mapwidget.h"
#include <QToolButton>
#include <QGraphicsLineItem>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QLabel>
#include <QComboBox>
#include <QSpinBox>
#include <QTextEdit>
#include <QPainter>
#include <QVector>

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
    void createToolBar();
    void paintEvent (QPaintEvent *);
    void setStart(int X, int Y);
    void setEnd(int X, int Y);
    void setNextPos (int index);
    void initScene();
public slots:
    void setStartStation();
    void setEndStation();
    void FindPath();
    void Clear();
private:
    MapWidget *mapWidget;
    QLabel *startLabel;
    QLabel *endLabel;
    QComboBox *startComboBox;
    QComboBox *endComboBox;
    QToolButton *findPathBtn;
    QToolButton *clearBtn;

    QGraphicsScene *scene;
    QGraphicsView *view;

    int startX, startY, endX, endY;
    QVector<int> nextPath;

    struct ArcCell{  //弧信息
        int adj;     //对无权图有1，0表示是否相邻，对带权图，则为权值类型
    //    string info; //该弧的相关信息
    };

    //内部类
    static const int MAX_VERTEX_NUM = 31;
    static const int INF = 999999;

    struct MGraph{
        QVector<int> vexs;                                    //顶点集合
        //临接矩阵
        ArcCell arcs[MAX_VERTEX_NUM][MAX_VERTEX_NUM];
        int vexnum;                                           //顶点数
        int arcnum;                                           //边数
    //    int kind;                                           //图的类型
    };




    class DijkstraFindPath
    {
    public:
        DijkstraFindPath();
        MGraph mgraph;
        void CreateGraph();
//        void ShortestPath(int v0, PathMatrix &path, ShortPathTable &DP, int prev[]);
        int prev[MAX_VERTEX_NUM];  //最短路上的前驱顶点
        int d[MAX_VERTEX_NUM];     //表示边e = (u,v)的权值(不存在时为INF,不过d[i][i]=0)
        bool used[MAX_VERTEX_NUM]; //已经使用过的图
        void dijkstra(int startPos);      //求从起点startPos出发到各个顶点的最短距离
        QVector<int> get_Path(int endPos);//到顶点endPos的最短路
    };

    DijkstraFindPath *dj;
};

#endif // MAINWINDOW_H

//MainWidget.cpp
//最短路径算法，和界面的实现

#include "mainwindow.h"
#include <qdebug.h>
#include <QToolBar>
#include <QtAlgorithms>
#include <iostream>
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
//    mapWidget = new MapWidget;
//    painter = new QPainter();
    dj = new MainWindow::DijkstraFindPath();
    dj->CreateGraph ();
    scene = new QGraphicsScene;
    scene->setSceneRect (-100, -100, 700, 700);
    initScene();
    view = new QGraphicsView;
    view->setScene (scene);
    view->setMinimumSize (800, 800);
    view->show ();
    setCentralWidget (view);
    createToolBar ();  //实现一个工具栏
//    setCentralWidget (mapWidget);
//    setMinimumSize (600, 400);  //设置最小尺寸
}
MainWindow::DijkstraFindPath::DijkstraFindPath()
{
    mgraph.vexnum = 31;                      //初始化点数目
       for (int i = 0; i < mgraph.vexnum; i++) //初始化点编号
           mgraph.vexs.push_back (i);
       mgraph.arcnum = 80;                     //暂定
       for (int i = 0; i < mgraph.vexnum; i++) {
           for (int j = 0; j < mgraph.vexnum; j++) {
               if (i == j)
                   mgraph.arcs[i][j].adj = 0;
               else
                   mgraph.arcs[i][j].adj = INF;
   //            mgraph.arcs[i][j].info = "";
           }
       }
}
void MainWindow::DijkstraFindPath::CreateGraph ()
{
        mgraph.arcs[0][1].adj = mgraph.arcs[1][0].adj = 45;    //6 - 5
        mgraph.arcs[0][6].adj = mgraph.arcs[6][0].adj = 165;   //6 - 10
        mgraph.arcs[1][2].adj = mgraph.arcs[2][1].adj = 45;    //5 - 4
        mgraph.arcs[2][3].adj = mgraph.arcs[3][2].adj = 45;    //4 - 3
        mgraph.arcs[3][4].adj = mgraph.arcs[4][3].adj = 45;    //3 - 2
        mgraph.arcs[3][15].adj = mgraph.arcs[15][3].adj = 24;  //3 - 22
        mgraph.arcs[4][5].adj = mgraph.arcs[5][4].adj = 45;    //2 - 1
        mgraph.arcs[13][15].adj = mgraph.arcs[15][13].adj = 85;//23 - 22
        mgraph.arcs[0][13].adj = mgraph.arcs[13][0].adj = 55;  //6 - 23
        mgraph.arcs[13][2].adj = mgraph.arcs[2][13].adj = 50;  //23 - 4
        mgraph.arcs[5][11].adj = mgraph.arcs[11][5].adj = 65;  //1 - 一食堂
        mgraph.arcs[11][12].adj = mgraph.arcs[12][11].adj = 10;//一食堂-操场
        mgraph.arcs[11][27].adj = mgraph.arcs[27][11].adj = 85;//一食堂-祁通1
        mgraph.arcs[27][28].adj = mgraph.arcs[28][27].adj = 85;//祁通1-祁通2(路口)
        mgraph.arcs[5][29].adj = mgraph.arcs[29][5].adj = 87;  //一食堂-岔路口
        mgraph.arcs[29][9].adj = mgraph.arcs[9][29].adj = 80;  //岔路-7
        mgraph.arcs[29][11].adj = mgraph.arcs[11][29].adj = 60;//一食堂到岔路(通向7号楼的)
        mgraph.arcs[29][30].adj = mgraph.arcs[30][29].adj = 32;//岔路-祁通大道
        mgraph.arcs[30][10].adj = mgraph.arcs[10][30].adj = 90;//祁通大道-图书馆
        mgraph.arcs[30][28].adj = mgraph.arcs[28][30].adj = 80;//祁通大道-祁通2
        mgraph.arcs[28][26].adj = mgraph.arcs[26][28].adj = 15;//祁通2-方肇周
        mgraph.arcs[25][27].adj = mgraph.arcs[27][25].adj = 273;    //西大门-祁通1
        mgraph.arcs[27][28].adj = mgraph.arcs[28][27].adj = 184;//祁通1-祁通2
//        mgraph.arcs[25][12].adj = mgraph.arcs[12][25].adj = 108; //西大门-西操
        mgraph.arcs[5][12].adj = mgraph.arcs[12][5].adj = 70;  //1 - 操场
        mgraph.arcs[6][7].adj = mgraph.arcs[7][6].adj = 45;    //10 - 9
        mgraph.arcs[7][8].adj = mgraph.arcs[8][7].adj = 45;    //9 - 8
        mgraph.arcs[8][9].adj = mgraph.arcs[9][8].adj = 45;    //8 - 7
        mgraph.arcs[9][10].adj = mgraph.arcs[10][9].adj = 150; //7 - 图书馆
        mgraph.arcs[6][14].adj = mgraph.arcs[14][6].adj = 140; //10 - 13
        mgraph.arcs[14][16].adj = mgraph.arcs[16][14].adj = 39;//13 - 12
        mgraph.arcs[14][17].adj = mgraph.arcs[17][14].adj = 39;//13 - 16
        mgraph.arcs[16][18].adj = mgraph.arcs[18][16].adj = 39;//12 - 15
        mgraph.arcs[17][18].adj = mgraph.arcs[18][17].adj = 39;//16 - 15
        mgraph.arcs[18][19].adj = mgraph.arcs[19][18].adj = 39;//15 - 14
        mgraph.arcs[17][20].adj = mgraph.arcs[20][17].adj = 137;//16 - 19
        mgraph.arcs[20][21].adj = mgraph.arcs[21][20].adj = 39; //19 - 18
        mgraph.arcs[21][22].adj = mgraph.arcs[22][21].adj = 39; //18 - 17
        mgraph.arcs[19][22].adj = mgraph.arcs[22][19].adj = 130;//14 - 17
        mgraph.arcs[22][23].adj = mgraph.arcs[23][22].adj = 53; //17 - 二超
        mgraph.arcs[23][24].adj = mgraph.arcs[24][23].adj = 5;  //二超 - 二食堂
        mgraph.arcs[24][10].adj = mgraph.arcs[10][24].adj = 260;//二食堂-图书馆
        //以下处理细节
        mgraph.arcnum = 80;
}
void MainWindow::DijkstraFindPath::dijkstra (int startPos)
{
    for (int i = 0; i < mgraph.vexnum; i++) d[i] = INF;
    for (int i = 0; i < mgraph.vexnum; i++) used[i] = false;
    for (int i = 0; i < mgraph.vexnum; i++) prev[i] = -1;
    d[startPos] = 0;
    while (true) {
        int v = -1;
        for (int u = 0; u < mgraph.vexnum; u++) {
            if (!used[u] && (v == -1 || d[u] < d[v])) v = u;
        }
        if (v == -1) break;
        used[v] = true;
        for (int u = 0; u < mgraph.vexnum; u++) {
            if (d[u] > d[v] + mgraph.arcs[v][u].adj) {
                d[u] = d[v] + mgraph.arcs[v][u].adj;
                prev[u] = v;
            }
        }
    }
}
QVector<int> MainWindow::DijkstraFindPath::get_Path (int endPos)
{
    QVector<int> path;
    for ( ; endPos != -1; endPos = prev[endPos]) {
//        std::cout << "EndPos: " << endPos << ", ";
        path.push_back (endPos);
    }
    std::reverse(path.begin (), path.end ());
    return path;
}
void MainWindow::initScene ()
{
    QGraphicsPixmapItem *item =
            scene->addPixmap (QPixmap("NanTong.jpg"));
//    item->setFlag (QGraphicsItem::ItemIsMovable);
    item->setPos (-500, -420);
}
MainWindow::~MainWindow()
{
}
void MainWindow::createToolBar ()
{
    QToolBar *toolBar = addToolBar ("Tool");
    startLabel = new QLabel(tr("起点: "));
    startComboBox = new QComboBox;
    startComboBox->addItem (tr("公寓6号楼"));  //0
    startComboBox->addItem (tr("公寓5号楼"));  //1
    startComboBox->addItem (tr("公寓4号楼"));  //2
    startComboBox->addItem (tr("公寓3号楼"));  //3
    startComboBox->addItem (tr("公寓2号楼"));  //4
    startComboBox->addItem (tr("公寓1号楼"));  //5
    startComboBox->addItem (tr("公寓10号楼")); //6
    startComboBox->addItem (tr("公寓9号楼"));  //7
    startComboBox->addItem (tr("公寓8号楼"));  //8
    startComboBox->addItem (tr("公寓7号楼"));  //9
    startComboBox->addItem (tr("图书馆"));     //10
    startComboBox->addItem (tr("一食堂")); startComboBox->addItem (tr("西操场"));  //11 12
    startComboBox->addItem (tr("公寓23号楼")); startComboBox->addItem (tr("公寓13号楼")); //13 14
    startComboBox->addItem (tr("公寓22号楼")); startComboBox->addItem (tr("公寓12号楼")); //15 16
    startComboBox->addItem (tr("公寓楼16")); startComboBox->addItem (tr("公寓楼15"));     //17 18
    startComboBox->addItem (tr("公寓楼14"));  startComboBox->addItem (tr("公寓楼19"));    //19 20
    startComboBox->addItem (tr("公寓楼18")); startComboBox->addItem (tr("公寓楼17"));     //21 22
    startComboBox->addItem (tr("二超")); startComboBox->addItem (tr("二食堂"));           //23 24
    startComboBox->addItem (tr("西大门")); startComboBox->addItem (tr("方肇周教学楼"));    //25 26
    endLabel = new QLabel(tr("\t终点: "));
    endComboBox = new QComboBox;
    endComboBox->addItem (tr("公寓6号楼"));
    endComboBox->addItem (tr("公寓5号楼"));
    endComboBox->addItem (tr("公寓4号楼"));
    endComboBox->addItem (tr("公寓3号楼"));
    endComboBox->addItem (tr("公寓2号楼"));
    endComboBox->addItem (tr("公寓1号楼"));
    endComboBox->addItem (tr("公寓10号楼"));
    endComboBox->addItem (tr("公寓9号楼"));
    endComboBox->addItem (tr("公寓8号楼"));
    endComboBox->addItem (tr("公寓7号楼"));
    endComboBox->addItem (tr("图书馆"));
    endComboBox->addItem (tr("一食堂"));    endComboBox->addItem (tr("西操场"));
    endComboBox->addItem (tr("公寓23号楼"));endComboBox->addItem (tr("公寓13号楼"));
    endComboBox->addItem (tr("公寓22号楼"));endComboBox->addItem (tr("公寓12号楼"));
    endComboBox->addItem (tr("公寓楼16"));  endComboBox->addItem (tr("公寓楼15"));
    endComboBox->addItem (tr("公寓楼14"));  endComboBox->addItem (tr("公寓楼19"));
    endComboBox->addItem (tr("公寓楼18"));  endComboBox->addItem (tr("公寓楼17"));
    endComboBox->addItem (tr("二超"));      endComboBox->addItem (tr("二食堂"));
    endComboBox->addItem (tr("西大门"));    endComboBox->addItem (tr("方肇周教学楼"));
    connect (startComboBox, SIGNAL(activated(int)), this, SLOT(setStartStation()));
    connect (endComboBox, SIGNAL(activated(int)), this, SLOT(setEndStation()));
    findPathBtn = new QToolButton;
    findPathBtn->setText (tr("\t\t绘制最短路径"));
    connect (findPathBtn, SIGNAL(clicked(bool)), this, SLOT(FindPath()));
    clearBtn = new QToolButton;
    clearBtn->setText (tr("\t\t清除"));
    connect (clearBtn, SIGNAL(clicked(bool)), this, SLOT(Clear()));
    toolBar->addWidget (startLabel);
    toolBar->addWidget (startComboBox);
    toolBar->addWidget (endLabel);
    toolBar->addWidget (endComboBox);
    toolBar->addWidget (findPathBtn);
    toolBar->addWidget (clearBtn);
}
void MainWindow::setStart(int X, int Y) {
    startX = X; startY = Y;
//    qDebug() << X << ", " << Y;
}
void MainWindow::setEnd (int X, int Y)
{
    endX = X; endY = Y;
}
void MainWindow::setStartStation ()
{
    switch (startComboBox->currentIndex ()) {
    case 0:
        setStart(-660, -534); break;
    case 1:
        setStart (-673, -490); break;
    case 2:
        setStart (-682, -446); break;
    case 3:
        setStart (-690, -400); break;
    case 4:
        setStart (-701, -355); break;
    case 5:
        setStart (-711, -310); break;
    case 6:
        setStart (-457, -555); break;
    case 7:
        setStart (-449, -485); break;
    case 8:
        setStart(-446, -432); break;
    case 9:
        setStart (-451, -400); break;
    case 10:
        setStart (-347, -353); break;
    case 11:
        setStart (-720, -247); break;
    case 12:
        setStart (-789, -252); break;
    case 13:
        setStart (-721, -517); break;
    case 14:
        setStart (-271, -540); break;
    case 15:
        setStart (-721, -439); break;
    case 16:
        setStart (-274, -495); break;
    case 17:
        setStart (-180, -552); break;
    case 18:
        setStart (-178, -508); break;
    case 19:
        setStart (-179, -456); break;
    case 20:
        setStart (-73, -549); break;
    case 21:
        setStart (-56, -500); break;
    case 22:
        setStart (-59, -448); break;
    case 23:
        setStart (-94, -381); break;
    case 24:
        setStart (-69, -351); break;
    case 25:
        setStart (-1070, -92); break;
    case 26:
        setStart (-438, -125); break;
    case 27:
        setStart (-721, -119); break;
    case 28:
        setStart (-550, -122); break;
    case 29:
        setStart (-555, -263); break;
    case 30:
        setStart (-498, -235); break;
    default:
        break;
    }
}
void MainWindow::setEndStation ()
{
    switch (endComboBox->currentIndex ()) {
    case 0:
        setEnd(-660, -534); break;
    case 1:
        setEnd (-673, -490); break;
    case 2:
        setEnd (-682, -446); break;
    case 3:
        setEnd (-690, -400); break;
    case 4:
        setEnd (-701, -355); break;
    case 5:
        setEnd (-711, -310); break;
    case 6:
        setEnd (-457, -555); break;
    case 7:
        setEnd (-449, -485); break;
    case 8:
        setEnd (-446, -432); break;
    case 9:
        setEnd (-451, -400); break;
    case 10:
        setEnd (-347, -353); break;
    case 11:
        setEnd (-720, -247); break;
    case 12:
        setEnd (-789, -252); break;
    case 13:
        setEnd (-721, -517); break;
    case 14:
        setEnd (-271, -540); break;
    case 15:
        setEnd (-721, -439); break;
    case 16:
        setEnd (-274, -495); break;
    case 17:
        setEnd (-180, -552); break;
    case 18:
        setEnd (-178, -508); break;
    case 19:
        setEnd (-179, -456); break;
    case 20:
        setEnd (-73, -549); break;
    case 21:
        setEnd (-56, -500); break;
    case 22:
        setEnd (-59, -448); break;
    case 23:
        setEnd (-94, -381); break;
    case 24:
        setEnd (-69, -351); break;
    case 25:
        setEnd (-1070, -92); break;
    case 26:
        setEnd (-438, -125); break;
    case 27:
        setEnd (-721, -119); break;
    case 28:
        setEnd (-550, -122); break;
    case 29:
        setEnd (-555, -263); break;
    case 30:
        setEnd (-498, -235); break;
    default:
        break;
    }
}
void MainWindow::setNextPos (int index)
{
    switch (index) {
    case 0:
        setEnd(-660, -534); break;
    case 1:
        setEnd (-673, -490); break;
    case 2:
        setEnd (-682, -446); break;
    case 3:
        setEnd (-690, -400); break;
    case 4:
        setEnd (-701, -355); break;
    case 5:
        setEnd (-711, -310); break;
    case 6:
        setEnd (-457, -555); break;
    case 7:
        setEnd (-449, -485); break;
    case 8:
        setEnd (-446, -432); break;
    case 9:
        setEnd (-451, -400); break;
    case 10:
        setEnd (-347, -353); break;
    case 11:
        setEnd (-720, -247); break;
    case 12:
        setEnd (-789, -252); break;
    case 13:
        setEnd (-721, -517); break;
    case 14:
        setEnd (-271, -540); break;
    case 15:
        setEnd (-721, -439); break;
    case 16:
        setEnd (-274, -495); break;
    case 17:
        setEnd (-180, -552); break;
    case 18:
        setEnd (-178, -508); break;
    case 19:
        setEnd (-179, -456); break;
    case 20:
        setEnd (-73, -549); break;
    case 21:
        setEnd (-56, -500); break;
    case 22:
        setEnd (-59, -448); break;
    case 23:
        setEnd (-94, -381); break;
    case 24:
        setEnd (-69, -351); break;
    case 25:
        setEnd (-1070, -92); break;
    case 26:
        setEnd (-438, -125); break;
    case 27:
        setEnd (-721, -119); break;
    case 28:
        setEnd (-550, -122); break;
    case 29:
        setEnd (-555, -263); break;
    case 30:
        setEnd (-498, -235); break;
    default:
        break;
    }
}
void MainWindow::FindPath ()
{
    //Demo 在图片上绘线 在原有基础上 (+700, +440);
    QVector<QPoint> v;
    dj->dijkstra (startComboBox->currentIndex ());
    //设置下一处的终点
    nextPath = dj->get_Path (endComboBox->currentIndex ());
    //准备绘制
    Clear ();
    //将路线绘制下来
    QGraphicsPathItem *item = new QGraphicsPathItem();
    QPen pen;
    pen.setWidth (4);
    pen.setColor (Qt::red);
    item->setPen (pen);
    item->setFlag (QGraphicsItem::ItemIsPanel);
//    qDebug() << startX << " " << startY << " " << endX << " " << endY;
//    qDebug() << "Hello World !";
    //设置起点
//    v << QPoint(startX + 700, startY + 440);
    for (int i = 1; i < nextPath.size (); i++) {
        qDebug() << nextPath[i] << " , ";
    }
    scene->addItem (item);
    QPainterPath pa;               //path
//    setNextPos (nextPath[1]);
//    item->setLine (startX + 700, startY + 440, endX + 700, endY + 440);
    pa.moveTo (startX + 700, startY + 440);
    for (int i = 1; i < nextPath.size() ; i++) {
        setNextPos (nextPath[i]);
        pa.lineTo (endX + 700, endY + 440);
    }
    item->setPath (pa);
}
void MainWindow::Clear ()
{
    QList<QGraphicsItem*> listItem = scene->items ();
    while (!listItem.empty ())
    {
        scene->removeItem (listItem.at (0));
        listItem.removeAt (0);
    }
    QGraphicsPixmapItem *item =
            scene->addPixmap (QPixmap("NanTong.jpg"));
//    item->setFlag (QGraphicsItem::ItemIsMovable);
    item->setPos (-500, -420);
}
void MainWindow::paintEvent (QPaintEvent *)
{

}

下面是main主函数调用。

//Main.cpp
#include "mainwindow.h"
#include "mapwidget.h"
#include <QApplication>
#include <QFont>
#include <QDebug>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QFont font("ARPL KaitiM GB", 12);
    font.setBold (true);
    a.setFont (font);

    qDebug() << "Run............";
    MainWindow w;
    w.show ();


    return a.exec();
}

end