交通信息工程实验一：编写读写GPS数据程序，熟悉GPS格式-CFANZ编程社区

编写读写GPS数据程序，熟悉GPS格式

1 熟悉GPS格式

对GPS中的各种格式所代表的内容进行熟悉，见附件EXCEL文件。

2 编写代码

对某一格式的GPS数据（数据文件：gps.txt）中的X，Y坐标读出，并通过界面绘出。

代码编写可采用任何一种语言，推荐VB（实验室电脑有VB C++等）

交通信息工程实验一：编写读写GPS数据程序，熟悉GPS格式_C++

注意以下问题：
（1）编写读取文件功能；
（2）数组使用；
（3）界面编写存在比例问题。
（4）对于电脑屏幕的0,0坐标倒置可以忽略。

测试代码（C++版 - 验证中…）

// 练习简易画图View.cpp : implementation of the CMyView class
//

#include "stdafx.h"
#include "练习简易画图.h"

#include "练习简易画图Doc.h"
#include "练习简易画图View.h"
#include <vector>
#include <algorithm>
#include <ostream>
#include <fstream>
#include<iostream>
#include<iomanip>
#include<string>
#include<sstream>
using namespace std;
//数据类型转换模板函数 
template <class Type>    
Type stringToNum(const string str)   
{        
    istringstream iss(str);       
    Type num;       
    iss >> num;       
    return num;       
}
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/
// CMyView

IMPLEMENT_DYNCREATE(CMyView, CView)

BEGIN_MESSAGE_MAP(CMyView, CView)
    //{{AFX_MSG_MAP(CMyView)
    ON_WM_LBUTTONDOWN()
    ON_WM_MOUSEMOVE()
    ON_WM_LBUTTONUP()
    ON_WM_PAINT()
    ON_COMMAND(ID_LINE, OnLine)
    ON_COMMAND(gps, Ongps)
    //}}AFX_MSG_MAP
    // Standard printing commands
    ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint)
    ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint)
    ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview)
END_MESSAGE_MAP()

/
// CMyView construction/destruction

CMyView::CMyView()
{
    shape=1;
    w=1;
    penstyle=PS_SOLID;
    m_down=false;
    m_ncolor=RGB(0,0,0);
    m_fcolor=RGB(0,0,0);


    // TODO: add construction code here

}

CMyView::~CMyView()
{
}

BOOL CMyView::PreCreateWindow(CREATESTRUCT& cs)
{
    // TODO: Modify the Window class or styles here by modifying
    //  the CREATESTRUCT cs

    return CView::PreCreateWindow(cs);
}

/
// CMyView drawing

void CMyView::OnDraw(CDC* pDC)
{
    CMyDoc* pDoc = GetDocument();
    ASSERT_VALID(pDoc);
    // TODO: add draw code for native data here
}

/
// CMyView printing

BOOL CMyView::OnPreparePrinting(CPrintInfo* pInfo)
{
    // default preparation
    return DoPreparePrinting(pInfo);
}

void CMyView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
    // TODO: add extra initialization before printing
}

void CMyView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
    // TODO: add cleanup after printing
}

/
// CMyView diagnostics

#ifdef _DEBUG
void CMyView::AssertValid() const
{
    CView::AssertValid();
}

void CMyView::Dump(CDumpContext& dc) const
{
    CView::Dump(dc);
}

CMyDoc* CMyView::GetDocument() // non-debug version is inline
{
    ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CMyDoc)));
    return (CMyDoc*)m_pDocument;
}
#endif //_DEBUG

/
// CMyView message handlers

void CMyView::OnLButtonDown(UINT nFlags, CPoint point) 
{

//  m_down=true;
//  SetCapture();
//  point1=point;
//  ReleaseCapture();
//  // TODO: Add your message handler code here and/or call default
    
//  CView::OnLButtonDown(nFlags, point);
}

void CMyView::OnMouseMove(UINT nFlags, CPoint point) 
{

//  if(m_down)
//  {
//      point2=point;
//      CClientDC dc(this);
//  }
    
    // TODO: Add your message handler code here and/or call default
    
//  CView::OnMouseMove(nFlags, point);
}

void CMyView::OnLButtonUp(UINT nFlags, CPoint point) 
{
    m_down=false;
    Invalidate(0);




    // TODO: Add your message handler code here and/or call default
    
    CView::OnLButtonUp(nFlags, point);
}

void CMyView::OnPaint() 
{
    CPaintDC dc(this); // device context for painting
    
//  CPaintDC dc(this); // device context for painting
    CPen pen;
    CBrush brush;
    pen.CreatePen(penstyle,w,m_ncolor);
    brush.CreateSolidBrush(m_fcolor);
    
    dc.SelectObject(&pen);
    dc.SelectObject(&brush);
    //dc.TextOut(100,100,m_show);
    
    if(1==shape)
    {
    dc.MoveTo(point1.x,point1.y);
    dc.LineTo(point2.x,point2.y);
    //dc.MoveTo(10,20);
    //dc.LineTo(30,40);

    }
    
    // TODO: Add your message handler code here
    
    // Do not call CView::OnPaint() for painting messages
}

void CMyView::OnLine() 
{

    shape=1;
}

void CMyView::Ongps() 
{
    // TODO: Add your command handler code here
    ifstream is("gps.txt");  
    std::string line;  
    getline(is,line);    
    //读取第一行 GGA格式  $GPGGA,025620.00,2602.33721,N,11911.49176,E,2,04,1.63,13.5,M,9.9,M,,0000*5D
    
    //GGA字段含义   语句ID,UTC时间，纬度，N/S，经度，E/W，GPS状态，卫星数量，精度因子，海拔 。。。   
    vector<string> arr1;  //定义一个字符串容器  
    int position = 0;  
    do 
    {   
        string tmp_s;    position = line.find(","); //找到逗号的位置   
        tmp_s = line.substr(0,position); //截取需要的字符串    
        line.erase(0,position+1); //将已读取的数据删去     
        arr1.push_back(tmp_s);   //将字符串压入容器中  
    }while(position != -1);  
    is.close();   
//  int length = _ttoi(_T(arr1[2]));//字符串转整型
//  MessageBox(arr1[2]);
//      cout<<"x"<<endl;
    //构造日期时间字符串 YYYY-MM-DD HH:MM:SS   
//  float d0 = stringToNum<float>(arr1[2]);  
//    float d1 = stringToNum<float>(arr1[4]);  

    //  cout<<"经度：";  
//  printf("%lf\n",d0/100);
//  shape=1;
//  point1.x=d0/100;
//  point1.y=d1/100;
//  point2.x=d0/100+10;
//  point2.y=d1/100+10;
    //此处不能使用cout，否则输出精度将受到影响  
//  cout<<"纬度：";  
//  printf("%lf\n",d1/100);   
//  cout<<"海拔："<<arr1[9]<<arr1[10]<<endl;  
}