QT_地圖導航 源碼下載

https://github.com/douzujun/MyMapView

主要算法講解：

1. 計算最短路徑（dijkstra算法）

Step1:

　　（1）找到最短路徑已經確定的頂點，從它已經確定的頂點，從它除法更新相鄰頂點的最短距離。

　　（2）此后不需要再關心1中的“最短距離已經確定的頂點”。

　　（3）在（1）和（2）中提到的“最短距離已經確定的頂點”要求解的關鍵。在最開始時，只有起點的最短距離是確定的。而在尚未使用過的頂點中，距離d[i]最小的頂點就是最短距離已經確定的頂點。這是因為由於不存在負邊，所以d[i]不會在更新中變小。

定義幾個方便算法描述的變量:

　　int cost[MAX_V][MAX_V]; //cost[u][v]表示表e=（u，v）的權值（不存在這條邊時設為INF）

　　int d[MAX_V];                 //頂點s出發的最短路徑

　　bool used[MAX_V];          //已經使用的圖

Step2:

　　（1）如果，我們需要輸出最短路的路徑。注，在求解最短路徑時，滿足d[j] = d[k] + cost[k][j]的頂點k（d[j]是表示從起點開始到j的最短路徑距離，cost[k][j]是表示k到j的距離）,就是最短路上的頂點j的前驅結點，因此通過不斷尋找前驅結點就可以恢復最短路。時間復雜度是O(E)。

　　（2）如果，我們用prev[j]來記錄最短路上的頂點j的前驅，那么就可以在O(|V|)時間內完成最短路的恢復。在d[j]=d[k]+cost[k][j]更新時，修改prev[j]=k, 這樣就可以求得prev數組。在計算從起點s出發到j的最短路時，通過prev[j]就可以知道頂點j的前驅，因此不斷把j替換成prev[j]直到j = s為止即可。代碼如下：

1. 首先要對圖進行初始化，才能正常計算最短路徑

MainWindow::DijkstraFindPath::DijkstraFindPath()
{
    mgraph.vexnum = 40;                        //初始化點數目
       for (int i = 0; i < mgraph.vexnum; i++) //初始化點編號
           mgraph.vexs.push_back (i);
       mgraph.arcnum = 98;                     //邊數
       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;
           }
       }
}

2. 設置圖的景點之間的權值。

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-操場
        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][11].adj = mgraph.arcs[11][29].adj = 50;//一食堂到岔路(通向7號樓的)
        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-圖書館
        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;//西大門-祁通1
        mgraph.arcs[27][28].adj = mgraph.arcs[28][27].adj = 84; //祁通1-祁通2
        mgraph.arcs[5][12].adj = mgraph.arcs[12][5].adj = 70;   //1 - 操場
        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 - 圖書館
        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 = 20;//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

        //以下處理細節—這是景點之間的一小段路之間的權值，因為用界面繪制路線，會//出現弧狀的路線，所以需要定額外的坐標
        mgraph.arcs[30][31].adj = mgraph.arcs[31][30].adj = 30; //祁通大道-祁通大道2
        mgraph.arcs[31][32].adj = mgraph.arcs[32][31].adj = 10; //祁通大道2-祁通大道3
        mgraph.arcs[32][10].adj = mgraph.arcs[10][32].adj = 20; //祁通大道3-圖書館
        mgraph.arcs[10][33].adj = mgraph.arcs[33][10].adj = 80; //圖書館-祁通大道4
        mgraph.arcs[33][34].adj = mgraph.arcs[34][33].adj = 45; //祁通4-祁通5
        mgraph.arcs[34][24].adj = mgraph.arcs[24][34].adj = 45; //祁通5-二食堂
        mgraph.arcs[34][23].adj = mgraph.arcs[23][34].adj = 45; //祁通5-二超
        mgraph.arcs[33][35].adj = mgraph.arcs[35][33].adj = 30; //祁通4-通向14號樓的小道
        mgraph.arcs[35][19].adj = mgraph.arcs[19][35].adj = 10; //小道-14號樓
        mgraph.arcs[35][36].adj = mgraph.arcs[36][35].adj = 10; //小道14-小道15
        mgraph.arcs[36][18].adj = mgraph.arcs[18][36].adj = 10; //小道15-15
        mgraph.arcs[36][16].adj = mgraph.arcs[16][36].adj = 5;  //小道15-12
        mgraph.arcs[37][29].adj = mgraph.arcs[29][37].adj = 40; //岔路-岔路2
        mgraph.arcs[37][9].adj = mgraph.arcs[9][37].adj = 45;   //岔路2-7

}

3. 計算最短路徑，並對輸出路徑進行初始化工作。

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;
            }
        }
    }
}

4.存儲起點到終點之間的路徑。

QVector<int> MainWindow::DijkstraFindPath::get_Path (int endPos)
{
    QVector<int> path;
//保存景點之間的最短路徑上的全部景點
    for ( ; endPos != -1; endPos = prev[endPos]) {
        path.push_back (endPos);
    }
//由於路徑是從終點向起點保存的，還需要將路徑逆置。
    std::reverse(path.begin (), path.end ());
    return path;
}

 

全部代碼： 

1 首先要對圖進行初始化，才能正常計算最短路徑

/**
 * 主要功能:
 * 1. 繪制輸入起點，終點最短路徑
 * 2. 雙擊地點, 查看景點信息
 * 3. 修改景點圖片
 * 4. 打開測試地圖，查看地圖坐標，可縮放地圖.
 **/
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "mapwidget.h"
#include <QToolButton>
#include <QGraphicsLineItem>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QLabel>
#include <QComboBox>
#include <QTextEdit>
#include <QVector>
#include <QMouseEvent>
#include <QDialog>
#include <QPixmap>
#include <QGridLayout>
#include <QLineEdit>
#include <QFileDialog>
#include <QHBoxLayout>

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
    void createToolBar();
    void createAction();
    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();
    void Revise();
    void callOtherMap();
    void ShowDialog();
private:
    MapWidget *mapWidget;
    QLabel *startLabel;
    QLabel *endLabel;
    QComboBox *startComboBox;
    QComboBox *endComboBox;
    QComboBox *reviseComboBox;

    QAction *findPathAction;
    QAction *clearAction;
    QAction *reviseAction;
    QAction *callMap;

    QGraphicsScene *scene;
    QGraphicsView *view;

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

    /*
     * 圖的實現，和最短路徑算法聲明
     */
    struct ArcCell{    //弧信息
        int adj;       //對無權圖有1，0表示是否相鄰，對帶權圖，則為權值類型
    //    string info; //該弧的相關信息
    };


    //內部類
    static const int MAX_VERTEX_NUM = 50;
    static const int INF = 999999;

    struct MGraph{
        QVector<int> vexs;                                    //頂點集合
        //臨接矩陣
        ArcCell arcs[MAX_VERTEX_NUM][MAX_VERTEX_NUM];
        int vexnum;                                           //頂點數
        int arcnum;                                           //邊數
    //    int kind;                                             //圖的類型
    };

    class DijkstraFindPath
    {
    public:
        DijkstraFindPath();
        MGraph mgraph;
        void CreateGraph();

        int prev[MAX_VERTEX_NUM];  //最短路上的前驅頂點
        int d[MAX_VERTEX_NUM];     //表示邊e = (u,v)的權值(不存在時為INF,不過d[i][i]=0)
        bool used[MAX_VERTEX_NUM]; //已經使用過的圖
        void dijkstra(int startPos);      //求從起點startPos出發到各個頂點的最短距離
        QVector<int> get_Path(int endPos);//到頂點endPos的最短路
    };

    DijkstraFindPath *dj;

//鼠標事件
protected:
    void mouseDoubleClickEvent (QMouseEvent *e);
private:
    QPixmap library;      //圖書館
    QPixmap canteen;      //餐廳
    QPixmap jxjBuilding;  //計算機樓
    QPixmap westgate;     //西門
    QPixmap westground;   //西操
    QPixmap twoMarket;    //二超
    QString strPath;      //文件路徑
    QLabel *label;
};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include <qdebug.h>
#include <QToolBar>
#include <QtAlgorithms>
#include <iostream>
#include <windows.h>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    setWindowTitle ("可愛的豆豆豆 校園導航");
    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);

    createAction ();
    createToolBar ();           //實現一個工具欄
    setMinimumSize (800, 800);  //設置最小尺寸
    Sleep(2000);
}

MainWindow::DijkstraFindPath::DijkstraFindPath()
{
    mgraph.vexnum = 40;                        //初始化點數目
       for (int i = 0; i < mgraph.vexnum; i++) //初始化點編號
           mgraph.vexs.push_back (i);
       mgraph.arcnum = 98;                     //暫定
       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-操場
        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 = 50;//一食堂到岔路(通向7號樓的)
        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-圖書館
        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;   //西大門-祁通1
        mgraph.arcs[27][28].adj = mgraph.arcs[28][27].adj = 84;   //祁通1-祁通2
        mgraph.arcs[5][12].adj = mgraph.arcs[12][5].adj = 70;  //1 - 操場
        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 - 圖書館
        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 = 20;//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-圖書館

        //以下處理細節
        mgraph.arcs[30][31].adj = mgraph.arcs[31][30].adj = 30; //祁通大道-祁通大道2
        mgraph.arcs[31][32].adj = mgraph.arcs[32][31].adj = 10; //祁通大道2-祁通大道3
        mgraph.arcs[32][10].adj = mgraph.arcs[10][32].adj = 20; //祁通大道3-圖書館
        mgraph.arcs[10][33].adj = mgraph.arcs[33][10].adj = 80; //圖書館-祁通大道4
        mgraph.arcs[33][34].adj = mgraph.arcs[34][33].adj = 45; //祁通4-祁通5
        mgraph.arcs[34][24].adj = mgraph.arcs[24][34].adj = 45; //祁通5-二食堂
        mgraph.arcs[34][23].adj = mgraph.arcs[23][34].adj = 45; //祁通5-二超
        mgraph.arcs[33][35].adj = mgraph.arcs[35][33].adj = 30; //祁通4-通向14號樓的小道
        mgraph.arcs[35][19].adj = mgraph.arcs[19][35].adj = 10; //小道-14號樓
        mgraph.arcs[35][36].adj = mgraph.arcs[36][35].adj = 10; //小道14-小道15
        mgraph.arcs[36][18].adj = mgraph.arcs[18][36].adj = 10; //小道15-15
        mgraph.arcs[36][16].adj = mgraph.arcs[16][36].adj = 5;  //小道15-12
        mgraph.arcs[37][29].adj = mgraph.arcs[29][37].adj = 40; //岔路-岔路2
        mgraph.arcs[37][9].adj = mgraph.arcs[9][37].adj = 45;   //岔路2-7


}

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::createAction ()
{
    findPathAction = new QAction(QIcon("Search.png"),tr("搜索路徑"), this);
    findPathAction->setShortcut (tr("Ctrl+F"));
    findPathAction->setStatusTip (tr("搜索路徑"));
    connect (findPathAction, SIGNAL(triggered(bool)), this, SLOT(FindPath()));

    clearAction = new QAction(QIcon("Clear.png"), tr("清理路徑"), this);
    clearAction->setShortcut (tr("Ctrl+W"));
    clearAction->setStatusTip (tr("清理路徑"));
    connect (clearAction, SIGNAL(triggered(bool)), this, SLOT(Clear()));

    reviseAction = new QAction(QIcon("revise.png"), tr("修改景點"), this);
    reviseAction->setShortcut (tr("Ctrl+R"));
    clearAction->setStatusTip (tr("修改景點"));
    connect (reviseAction, SIGNAL(triggered(bool)), this, SLOT(Revise()));

    callMap = new QAction(QIcon("map.png"), tr("調用測試地圖"), this);
    callMap->setShortcut (tr("Ctrl+M"));
    callMap->setStatusTip (tr("調用測試地圖"));
    connect (callMap, SIGNAL(triggered(bool)), this, SLOT(callOtherMap()));

}

void MainWindow::createToolBar ()
{
    QToolBar *toolBar = addToolBar ("Tool");
    startLabel = new QLabel(tr("起點: "));
    startComboBox = new QComboBox;
    startComboBox->addItem (tr("公寓6號樓"));  //0
    startComboBox->addItem (tr("公寓5號樓"));  //1
    startComboBox->addItem (tr("公寓4號樓"));  //2
    startComboBox->addItem (tr("公寓3號樓"));  //3
    startComboBox->addItem (tr("公寓2號樓"));  //4
    startComboBox->addItem (tr("公寓1號樓"));  //5

    startComboBox->addItem (tr("公寓10號樓")); //6
    startComboBox->addItem (tr("公寓9號樓"));  //7
    startComboBox->addItem (tr("公寓8號樓"));  //8
    startComboBox->addItem (tr("公寓7號樓"));  //9
    startComboBox->addItem (tr("圖書館"));     //10
    startComboBox->addItem (tr("一食堂")); startComboBox->addItem (tr("西操場"));  //11 12
    startComboBox->addItem (tr("公寓23號樓")); startComboBox->addItem (tr("公寓13號樓")); //13 14
    startComboBox->addItem (tr("公寓22號樓")); startComboBox->addItem (tr("公寓12號樓")); //15 16
    startComboBox->addItem (tr("公寓樓16")); startComboBox->addItem (tr("公寓樓15"));     //17 18
    startComboBox->addItem (tr("公寓樓14"));  startComboBox->addItem (tr("公寓樓19"));    //19 20
    startComboBox->addItem (tr("公寓樓18")); startComboBox->addItem (tr("公寓樓17"));     //21 22
    startComboBox->addItem (tr("二超")); startComboBox->addItem (tr("二食堂"));           //23 24
    startComboBox->addItem (tr("西大門")); startComboBox->addItem (tr("方肇周教學樓"));    //25 26

    endLabel = new QLabel(tr("終點: "));

    endComboBox = new QComboBox;
    endComboBox->addItem (tr("公寓6號樓"));
    endComboBox->addItem (tr("公寓5號樓"));
    endComboBox->addItem (tr("公寓4號樓"));
    endComboBox->addItem (tr("公寓3號樓"));
    endComboBox->addItem (tr("公寓2號樓"));
    endComboBox->addItem (tr("公寓1號樓"));
    endComboBox->addItem (tr("公寓10號樓"));
    endComboBox->addItem (tr("公寓9號樓"));
    endComboBox->addItem (tr("公寓8號樓"));
    endComboBox->addItem (tr("公寓7號樓"));
    endComboBox->addItem (tr("圖書館"));
    endComboBox->addItem (tr("一食堂"));    endComboBox->addItem (tr("西操場"));
    endComboBox->addItem (tr("公寓23號樓"));endComboBox->addItem (tr("公寓13號樓"));
    endComboBox->addItem (tr("公寓22號樓"));endComboBox->addItem (tr("公寓12號樓"));
    endComboBox->addItem (tr("公寓樓16"));  endComboBox->addItem (tr("公寓樓15"));
    endComboBox->addItem (tr("公寓樓14"));  endComboBox->addItem (tr("公寓樓19"));
    endComboBox->addItem (tr("公寓樓18"));  endComboBox->addItem (tr("公寓樓17"));
    endComboBox->addItem (tr("二超"));      endComboBox->addItem (tr("二食堂"));
    endComboBox->addItem (tr("西大門"));    endComboBox->addItem (tr("方肇周教學樓"));

    connect (startComboBox, SIGNAL(activated(int)), this, SLOT(setStartStation()));
    connect (endComboBox, SIGNAL(activated(int)), this, SLOT(setEndStation()));

    toolBar->addWidget (startLabel);
    toolBar->addWidget (startComboBox);
    toolBar->addSeparator ();
    toolBar->addWidget (endLabel);
    toolBar->addWidget (endComboBox);
    toolBar->addSeparator ();
    toolBar->addAction(findPathAction);
    toolBar->addSeparator ();
    toolBar->addAction(clearAction);
    toolBar->addSeparator ();
    toolBar->addAction(reviseAction);
    toolBar->addSeparator ();
    toolBar->addAction(callMap);

}

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 (-328, -368); 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 (-41, -552); break;
    case 21:
        setStart (-56, -500); break;
    case 22:
        setStart (-59, -448); break;
    case 23:
        setStart (-83, -393); 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;
    case 31:
        setStart (-439, -306); break;
    case 32:
        setStart (-390, -344); break;
    case 33:
        setStart (-226, -386); break;
    case 34:
        setStart (-144, -370); break;
    case 35:
        setStart (-218, -454); break;
    case 36:
        setStart (-223, -495); break;
    case 37:
        setStart (-513, -379); 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 (-328, -368); 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 (-41, -552); break;
    case 21:
        setEnd (-56, -500); break;
    case 22:
        setEnd (-59, -448); break;
    case 23:
        setEnd (-83, -393); 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;
    case 31:
        setEnd (-439, -306); break;
    case 32:
        setEnd (-390, -344); break;
    case 33:
        setEnd (-226, -386); break;
    case 34:
        setEnd (-144, -370); break;
    case 35:
        setEnd (-218, -454); break;
    case 36:
        setEnd (-223, -495); break;
    case 37:
        setEnd (-513, -379); 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 (-328, -368); 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 (-41, -552); break;
    case 21:
        setEnd (-56, -500); break;
    case 22:
        setEnd (-59, -448); break;
    case 23:
        setEnd (-83, -393); 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;
    case 31:
        setEnd (-439, -306); break;
    case 32:
        setEnd (-390, -344); break;
    case 33:
        setEnd (-226, -386); break;
    case 34:
        setEnd (-144, -370); break;
    case 35:
        setEnd (-218, -454); break;
    case 36:
        setEnd (-223, -495); break;
    case 37:
        setEnd (-513, -379); break;
    default:
        break;
    }
}

void MainWindow::FindPath ()
{
    //Demo 在圖片上繪線 在原有基礎上 (+700, +440);
    QVector<QPoint> v;

    dj->dijkstra (startComboBox->currentIndex ());
    //設置下一處的終點
    nextPath = dj->get_Path (endComboBox->currentIndex ());

    //准備繪制
    Clear ();
    //將路線繪制下來
    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 !";


    for (int i = 1; i < nextPath.size (); i++) {
        qDebug() << nextPath[i] << " , ";
    }
    scene->addItem (item);

    QPainterPath pa;               //path

    pa.moveTo (startX + 700, startY + 440);

    //將路徑用坐標存入到路徑
    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::Revise ()
{
    QDialog *reviseDlg = new QDialog;
    QLabel *reviseLabel = new QLabel(tr("修改圖片路徑："));
    QLineEdit *revison = new QLineEdit(tr("\\image\\library.png"));
    QPushButton *SureBtn = new QPushButton(tr("確定"));
    QPushButton *CancelBtn = new QPushButton(tr("取消"));

    revison->setEnabled (false);

    reviseComboBox = new QComboBox;
    reviseComboBox->addItem (tr("圖書館"));
    reviseComboBox->addItem (tr("食堂"));
    reviseComboBox->addItem (tr("西操"));
    reviseComboBox->addItem (tr("jsj教學樓"));

    connect(reviseComboBox, SIGNAL(activated(int)), this, SLOT(ShowDialog()));
    connect (SureBtn, SIGNAL(clicked(bool)), reviseDlg, SLOT(close()));
    connect (CancelBtn, SIGNAL(clicked(bool)), reviseDlg, SLOT(close ()));

    revison->setText (strPath);

    QGridLayout *mainlayout = new QGridLayout(reviseDlg);
    mainlayout->addWidget (reviseLabel, 0, 0); mainlayout->addWidget (revison, 0, 1);
    mainlayout->addWidget (reviseComboBox, 0 , 2);
    mainlayout->addWidget (SureBtn, 1, 1, 1, 1); mainlayout->addWidget (CancelBtn, 1, 2, 1, 1);


    reviseDlg->setWindowTitle (tr("修改景點信息"));
    reviseDlg->show ();
}

void MainWindow::ShowDialog ()
{
    strPath = QFileDialog::getOpenFileName (this, "打開", "/", "PNG圖像(*.png)::JPEG圖像(*.jpg)");
    switch (reviseComboBox->currentIndex ()) {
    case 0:
        library.load (strPath); break;
    case 1:
        canteen.load (strPath); break;
    case 2:
        westground.load (strPath); break;
    case 3:
        jxjBuilding.load (strPath); break;
    default:
        break;
    }
}

//鼠標事件
void MainWindow::mouseDoubleClickEvent (QMouseEvent *e)
{
    QDialog *dialog = new QDialog;
    QGridLayout *layout = new QGridLayout(dialog);
    label = new QLabel;

    qDebug() << "x : " << e->x () << ", y : " << e->y ();
    //食堂(1060, 260)
    if ( (e->x () >= 1060-40 && e->x () <= 1060 + 40) &&
         (e->y () >= 260 - 10 && e->y () <= 260 + 10 ))
    {
        strPath = "images//canteen";
        canteen.load (strPath);
        label->setPixmap (canteen);
        layout->addWidget (label);
        dialog->setMinimumSize (1193, 274);
        dialog->setWindowTitle ("二食堂");
        dialog->show ();
    }
    else if ((e->x () >= 708-50 && e->x () <= 708 + 50) &&
             (e->y () >= 498 - 40 && e->y () <= 498 + 40 ) ) {
        strPath = "images//computer";
        jxjBuilding.load (strPath);
        label->setPixmap (jxjBuilding);
        layout->addWidget (label);
        dialog->setMinimumSize (437, 265);
        dialog->setWindowTitle ("計算機樓(方肇周教學樓)");
        dialog->show ();
    }
    else if ((e->x () >= 787-50 && e->x () <= 787 + 50) &&
             (e->y () >= 287 - 50 && e->y () <= 287 + 50 ) ) {
        strPath = "images//library";
        library.load (strPath);
        label->setPixmap (library);
        layout->addWidget (label);
        dialog->setMinimumSize (397, 340);
        dialog->setWindowTitle ("圖書館");
        dialog->show ();
    }
    else if ((e->x () >= 64-50 && e->x () <= 64 + 100) &&
             (e->y () >= 516 - 100 && e->y () <= 516 + 100 ) ) {
        strPath = "images//westgate";
        westgate.load (strPath);
        label->setPixmap (westgate);
        layout->addWidget (label);
        dialog->setMinimumSize (1100, 283);
        dialog->setWindowTitle ("西大門");
        dialog->show ();
    }
    else if ((e->x () >= 200-200 && e->x () <= 200 + 200) &&
             (e->y () >= 167 - 500 && e->y () <= 167 + 500 ) ) {
        strPath = "images//westground";
        westground.load (strPath);
        label->setPixmap (westground);
        layout->addWidget (label);
        dialog->setMinimumSize (395, 345);
        dialog->setWindowTitle ("西操");
        dialog->show ();
    }
    else if ((e->x () >= 1045 - 5 && e->x () <= 1045 + 5) &&
             (e->y () >= 233 - 5 && e->y () <= 233 + 5 ) ) {
        strPath = "images//twoMarket";
        twoMarket.load (strPath);
        label->setPixmap (twoMarket);
        layout->addWidget (label);
        dialog->setMinimumSize (611, 294);
        dialog->setWindowTitle ("二超");
        dialog->show ();
    }
}

void MainWindow::callOtherMap ()
{
    mapWidget = new MapWidget;
    mapWidget->show ();
}

#ifndef MAPWIDGET_H
#define MAPWIDGET_H

#include <QGraphicsView>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>
#include <QMouseEvent>

class MapWidget : public QGraphicsView
{
    Q_OBJECT
public:
    MapWidget();
    void readMap();                //讀取地圖信息
    QPointF mapToMap(QPointF);     //用於實現場景坐標系與地圖坐標間的映射.以獲得某點的經緯度

public slots:
    void slotZoom(int);            //縮放信號
protected:
    //完成地圖的顯示功能
    void drawBackground (QPainter *painter, const QRectF &rect);

    void mouseMoveEvent (QMouseEvent *event);
private:
    QPixmap map;
    qreal zoom;
    QLabel *viewCoord;  //視圖目前坐標(以窗口左上為原點)
    QLabel *sceneCoord; //場景目前坐標(以場景中心為原點)
    QLabel *mapCoord;   //地圖目前坐標


    double x1, y1;
    double x2, y2;

};

#endif // MAPWIDGET_H

#include "mapwidget.h"
#include <QSlider>         //滑動條
#include <QGridLayout>
#include <QFile>
#include <QTextStream>
#include <QGraphicsScene>
#include <math.h>

MapWidget::MapWidget()
{
    //讀取地圖信息--用於讀取描述地圖信息的文件(包括地圖名及經緯度等信息)
    readMap ();
    zoom = 50;
    int width = map.width ();
    int height = map.height ();
    //新建一個QGraphicsScene對象為主窗口連接一個場景
    QGraphicsScene *scene = new QGraphicsScene(this);
    //限定場景的顯示區域為地圖大小
    scene->setSceneRect (-width/2, -height/2, width, height);
    setScene (scene);
    /***
     * The background is cached(隱藏，緩存). This affects both custom backgrounds, and
     * backgrounds based on the backgroundBrush property. When this flag is enabled,
     * QGraphicsView will allocate one pixmap with the full size of the viewport
     */
    setCacheMode (CacheBackground);
    /***
     * 用於地圖縮放的滑動條
     * 新建一個QSlider對象作為地圖的縮放控制
     */
    QSlider *slider = new QSlider;
    //設置滾動條方向-垂直
    slider->setOrientation (Qt::Vertical);
    slider->setRange (1, 100);        //設置地圖縮放比例值范圍為0~100
    slider->setTickInterval (10);     //顯示刻度間隔為10
    slider->setValue (0);            //設置當前初始值為50
    // 將縮放控制條的valueChanged()信號與地圖縮放slotZoom()槽函數相關聯
    connect (slider, SIGNAL(valueChanged(int)), this, SLOT(slotZoom(int)));

    //縮放圖標
    QLabel *zoominLabel = new QLabel;
    zoominLabel->setScaledContents (true);
    zoominLabel->setPixmap (QPixmap("zoomin.png"));
    QLabel *zoomoutLabel = new QLabel;
    zoomoutLabel->setScaledContents (true);
    zoomoutLabel->setPixmap (QPixmap("zoomout.png"));

    //坐標值顯示區
    QLabel *label1 = new QLabel(tr("GraphicsView:"));
    viewCoord = new QLabel;
    QLabel *label2 = new QLabel(tr("GraphicsScene:"));
    sceneCoord = new QLabel;
    QLabel *label3 = new QLabel(tr("map:"));
    mapCoord = new QLabel;

    //坐標顯示區布局
    QGridLayout *gridLayout = new QGridLayout;
    gridLayout->addWidget (label1, 0, 0);
    gridLayout->addWidget (viewCoord, 0, 1);

    gridLayout->addWidget (label2, 1, 0);
    gridLayout->addWidget (sceneCoord, 1, 1);

    gridLayout->addWidget (label3, 2, 0);
    gridLayout->addWidget (mapCoord, 2, 1);

    gridLayout->setSizeConstraint (QLayout::SetFixedSize);
    QFrame *coordFrame = new QFrame;
    coordFrame->setLayout (gridLayout);

    //縮放控制子布局
    QVBoxLayout *zoomLayout = new QVBoxLayout;
    zoomLayout->addWidget (zoominLabel);
    zoomLayout->addWidget (slider);
    zoomLayout->addWidget (zoomoutLabel);

    //坐標顯示區布局
    QVBoxLayout *coordLayout = new QVBoxLayout;
    coordLayout->addWidget (coordFrame);
    coordLayout->addStretch ();
    //主布局
    QHBoxLayout *mainLayout = new QHBoxLayout;
    mainLayout->addLayout (zoomLayout);
    mainLayout->addLayout (coordLayout);
    mainLayout->addStretch ();          //平均分割
    mainLayout->setMargin (30);         //設置對話框(或窗體)的邊距為30
    mainLayout->setSpacing (10);        //設定各個控件之間的間距為10
    setLayout (mainLayout);             //在場景中設置為布局

    setWindowTitle ("Map Widget");
    setMinimumSize (600, 400);
}

//讀取地圖信息
void MapWidget::readMap ()
{
    QString mapName;
    //新建一個QFile對象，“map.txt"是描述地圖信息的文本文件
    QFile mapFile("maps.txt");
    //以"只讀"的方式打開此文件
    int ok = mapFile.open (QIODevice::ReadOnly);
    if (ok)                   //分別以讀取地圖的名稱和四個經緯度信息
    {
        QTextStream ts(&mapFile);
        if (!ts.atEnd ()) {              //沒有到末尾返回false
            ts >> mapName;               //儲存字符串
            ts >> x1 >> y1 >> x2 >> y2;  //儲存地圖左上角和右下角的經緯度
        }
    }
    map.load (mapName);      //將地圖讀取至私有標量map中
}

//根據縮放滑動條的當前值,確定縮放的比例,調用scale()函數實現地圖縮放--完成地圖縮放功能slotZoom
void MapWidget::slotZoom (int value)
{
    qreal s;                  //縮放大小
    if (value > zoom) {       //放大
        s = pow (1.01, (value - zoom));
    }
    else {
        s = pow(1/1.01, (zoom - value));
    }
    scale(s, s);
    zoom = value;            //當前放大值
}

//drawBackground()--以地圖圖片重繪場景的背景來實現地圖顯示
void MapWidget::drawBackground (QPainter *painter, const QRectF &rect)
{
    /***
     * The scene rectangle defines the extent of the scene, and in the view's case,
     * this means the area of the scene that you can navigate using the scroll bars.
     */
    painter->drawPixmap (int(sceneRect ().left ()) + 10, int(sceneRect ().top ()) - 10, map);

}

//完成某點在各層坐標中的映射及顯示
void MapWidget::mouseMoveEvent (QMouseEvent *event)
{
    //QGraphicesView 坐標
    QPoint viewPoint = event->pos ();   //鼠標事件位置
    viewCoord->setText (QString::number (viewPoint.x ()) + "," + QString::number (viewPoint.y ()));

    //QGraphiccsScene 坐標 -- 將視圖坐標轉換成場景坐標
    QPointF scenePoint = mapToScene (viewPoint);
    sceneCoord->setText (QString::number (scenePoint.x ()) + "," + QString::number (scenePoint.y ()));

    //地圖坐標(經，緯度值)
    QPointF latLon = mapToMap (scenePoint);
    mapCoord->setText (QString::number (latLon.x ()) + "," + QString::number (latLon.y ()));


}

//完成從場景至地圖坐標的轉換mapToMap()
QPointF MapWidget::mapToMap (QPointF p)
{
    QPointF latLon;       //地圖坐標
    qreal w = sceneRect ().width ();      //場景長度
    qreal h = sceneRect ().height ();     //場景高度
    qreal lon = y1 - ( (h/2+p.y ()) * abs(y1-y2)/h );
    qreal lat = x1 + ( (w/2+p.x ()) * abs(x1-x2)/w );

    latLon.setX (lat);
    latLon.setY (lon);
    return latLon;
}

#include "mainwindow.h"
#include "mapwidget.h"
#include <QApplication>
#include <QFont>
#include <QDebug>
#include <QPixmap>
#include <QSplashScreen>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QPixmap pixmap("312");        //創建QPixmap對象，設置啟動圖片
    QSplashScreen splash(pixmap); //利用QPixmap對象創建一個QSplashScreen對象
    splash.show ();               //顯示此啟動圖片

    a.processEvents ();           //使程序在顯示啟動動畫的同時能能響應鼠標等其他事件

    QFont font("ARPL KaitiM GB", 12);
    font.setBold (true);
    a.setFont (font);

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

    //表示在主窗體對象初始化完成后，結束啟動畫面
    splash.finish (&w);


    return a.exec();
}

 源碼下載: http://pan.baidu.com/s/1boEzMJt

 qt新手，如有錯誤，希望大神們指正~