读取XML中的信息GDAL生成shp文件

在上一篇介绍了通过影像获取边界范围，这一篇介绍通过XML获取影像边界范围，不过下面是生成的点图层，需要的可以改为面图层。

在国产卫星影像（如GF1，GF2）压缩包中，通常会存在一个XML文件，里面存有一些影像的基本信息，先需要通过XML中的四角点的坐标生成一个shp文件，即影像对应的有效范围边框。

在此也非常感谢提供Markup.h和Markup.cpp（需要的可以去我的资源中下载）的那个朋友<img alt="微笑" src="http://static.blog.csdn.net/xheditor/xheditor_emot/default/smile.gif" />，帮我解决了一个大问题。也希望这能帮助需要的朋友。

<ImgFour_points(const char *pszXMLFileName, const char *pszDSTShpFileName)
{
CMarkup xml;
bool load=false;

load=xml.Load(pszXMLFileName);
xml.ResetMainPos();
if (load)
{
cout<<"从XML提取影像四角点并生成点shp图层..."<<endl;
//获取四个点坐标
vector<Point_xy> BoundaryPoint;
Point_xy temPoint;   //点结构体对象

if (xml.FindChildElem("SatelliteID"))
cout<<"卫星："<<xml.GetChildData()<<endl;
if(xml.FindChildElem("SceneID"))
cout<<"景序列号："<<xml.GetChildData()<<endl;

<span style="white-space:pre">		</span>//XML中的四个点坐标
if(xml.FindChildElem("TopLeftLatitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));  //为了CString 转为 double
temPoint.y =atof(str.GetBuffer(str.GetLength()));

<span style="white-space:pre">		</span>	}
if(xml.FindChildElem("TopLeftLongitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));
temPoint.x =atof(str.GetBuffer(str.GetLength()));
}
BoundaryPoint.push_back(temPoint);    //加入Vector为了后面shp的生成

if(xml.FindChildElem("TopRightLatitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));
temPoint.y =atof(str.GetBuffer(str.GetLength()));
}
if(xml.FindChildElem("TopRightLongitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));
temPoint.x =atof(str.GetBuffer(str.GetLength()));
//	temPoint.x = xml.GetChildData();
//	cout<<"TopRightLongitude"<<xml.GetChildData()<<endl;
}
BoundaryPoint.push_back(temPoint);

if(xml.FindChildElem("BottomRightLatitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));
temPoint.y =atof(str.GetBuffer(str.GetLength()));
}
if(xml.FindChildElem("BottomRightLongitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));
temPoint.x =atof(str.GetBuffer(str.GetLength()));
}
BoundaryPoint.push_back(temPoint);

if(xml.FindChildElem("BottomLeftLatitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));
temPoint.y =atof(str.GetBuffer(str.GetLength()));
}
if(xml.FindChildElem("BottomLeftLongitude"))
{
CString str = (xml.GetChildData().GetBuffer(0));
temPoint.x =atof(str.GetBuffer(str.GetLength()));

}
BoundaryPoint.push_back(temPoint);

//为了支持中文路径
CPLSetConfigOption("GDAL_FILENAME_IS_UTF8","NO");

//注册shape文件驱动
const char* pszDriverName="ESRI Shapefile";
OGRSFDriver *poDriver;
OGRRegisterAll();
poDriver=OGRSFDriverRegistrar::GetRegistrar()->GetDriverByName(pszDriverName);
if (poDriver==NULL)
{
printf("%s driver is not available!",pszDriverName);
exit(1);
}
//创建shape文件;
OGRDataSource *poShpDS;

//如果名字有.shp后缀，则直接在当前目录下生成文件;
poShpDS=poDriver->CreateDataSource(pszDSTShpFileName,NULL);
if (poShpDS==NULL)
{
printf("Create my shape file failed!");
exit(1);
}
//创建输出图层;
OGRLayer *poLayer;;

//为shp设置地理坐标
OGRSpatialReference oSRS;
char    *pszWKT = NULL;
oSRS.SetWellKnownGeogCS( "WGS84" );
oSRS.exportToWkt( &pszWKT );
//	printf( "%s\n", pszWKT );

poLayer=poShpDS->CreateLayer(pszDSTShpFileName,&oSRS, wkbPoint, NULL);
if (poLayer==NULL)
{
printf("Creat layer failed!");
exit(1);
}
//添加属性字段
OGRFieldDefn oFieldfilename("ImgName",OFTString);
oFieldfilename.SetWidth(100);

if (poLayer->CreateField(&oFieldfilename,1)!=OGRERR_NONE)
{
printf("Create Point Field Failed!");
exit(1);
}
OGRFieldDefn oFieldX("X",OFTReal);
if (poLayer->CreateField(&oFieldX,1)!=OGRERR_NONE)
{
printf("Create Point Field Failed!");
exit(1);
}
OGRFieldDefn oFieldY("Y",OFTReal);
if (poLayer->CreateField(&oFieldY,1)!=OGRERR_NONE)
{
printf("Create Point Field Failed!");
exit(1);
}

//创建features，写入feature到磁盘;
OGRFeature *poFeature;
poFeature=OGRFeature::CreateFeature(poLayer->GetLayerDefn());

//添加属性信息
string path = pszXMLFileName;
int pos = path.find_last_of('\\');
string tifName(path.substr(pos + 1) );

poFeature->SetField("ImgName",tifName.c_str());
//绘制外边框
OGRLineString Line;
OGRLinearRing ob_LinearRing;

for (int n_point = 0; n_point < BoundaryPoint.size(); n_point++ )
{
OGRPoint Point(BoundaryPoint[n_point].x , BoundaryPoint[n_point].y );
poFeature->SetField("X",BoundaryPoint[n_point].x);
poFeature->SetField("Y",BoundaryPoint[n_point].y);

poFeature->SetGeometry(&Point);

if (poLayer->CreateFeature(poFeature)!=OGRERR_NONE)
{
printf("Failed create feature in shapefile！");
exit(1);
}
}

OGRFeature::DestroyFeature(poFeature);
OGRDataSource::DestroyDataSource(poShpDS);
printf("创建矢量数据成功！\n");

cout<<"BoundaryPoint.capacity :"<<BoundaryPoint.capacity()<<endl;
vector<Point_xy>().swap(BoundaryPoint);
cout<<"BoundaryPoint.capacity :"<<BoundaryPoint.capacity()<<endl;

}

}