GDAL读写shp文件

来源：互联网发布：telnet 端口失败解决编辑：程序博客网时间：2024/05/18 18:14

原文网址：http://www.189works.com/article-18614-1.html

GDAL读shp文件
（1) 注册所有的文件格式驱动
1 GDALAllRegister();
2 OGRRegisterAll();
（2）得到shp文件的处理器
1 OGRSFDriver* poDriver = Registrar::GetRegistrar()->GetDriverByName("ESRI Shapefile");
（3）打开shp文件
1 OGRDataSource* poDS = poDriver->Open( "D:\\lakes.shp", NULL );
（4）获取shp图层
1 OGRLayer* poLayer = poDS->GetLayer(0);
（5）读取几何和属性值
1 OGRFeature * pFeature;
2 while ((pFeature=poLayer->GetNextFeature())!=NULL)
3 {
4    OGRGeometry* pGeometry = pFeature->GetGeometryRef();
5    if (pGeometry == NULL)
6    {
7        AfxMessageBox("Geometry get failed.");
8        return FALSE;
9    }
10
11    OGRwkbGeometryType geoType = pGeometry->getGeometryType();
12    if (wkbPoint==geoType)
13      CString strNodeID = pFeature->GetFieldAsString("NodeID");
14    else if (wkbLineString==geoType)
15    {
16        OGRLineString* pLineGeo = (OGRLineString*)pGeometry;
17        double staX = pLineGeo->getX(0);
18        double staY = pLineGeo->getY(0);
19    }
20 }
（6）资源清理
1 OGRDataSource::DestroyDataSource( poDS );
2 OGRCleanupAll();
GDAL写shp文件
（1) 注册所有的文件格式驱动
1 GDALAllRegister();
2 OGRRegisterAll();
（2）得到shp文件的处理器
1 OGRSFDriver* poDriver = Registrar::GetRegistrar()->GetDriverByName("ESRI Shapefile");
（3）创建shp文件
1 OGRDataSource* poDS = poDriver->CreateDataSource( "D:\\lakes.shp", NULL );
（4）创建图层
OGRLayer* poLayer= poDS->CreateLayer( "tbLine", NULL, wkbLineString, NULL );
（5）创建字段
1 // 字符串
2 OGRFieldDefn oField1("GeoObjNum",OFTString);
3 oField1.SetWidth(8);
4 if( poLayer->CreateField( &oField1 ) != OGRERR_NONE ){
5    AfxMessageBox( "Creating Name field failed.\n" );return FALSE;}
6
7 // 浮点数
8 OGRFieldDefn oField2("LBTG",OFTReal);
9 oField2.SetPrecision(3);
10 if( poLayer->CreateField( &oField2 ) != OGRERR_NONE ){
11    AfxMessageBox( "Creating Name field failed.\n" );return FALSE;}
12
13 // 整型
14 OGRFieldDefn oField3("Number",OFTInteger);
15 if( poLayer->CreateField( &oField3 ) != OGRERR_NONE ){
16    AfxMessageBox( "Creating Name field failed.\n" );return FALSE;}
（6）创建几何和Feature
1 GRFeature *poFeature;
2 poFeature = new OGRFeature( poLayer->GetLayerDefn() );
3
4 poFeature->SetField( "GeoObjNum", strGeoObjNum );
5 poFeature->SetField( "LBTG", fLBTG );
6 poFeature->SetField( "Number", number );
7
8 OGRLineString *poLine = new OGRLineString();
9
10 poLine->setNumPoints(2);
11 poLine->setPoint(0,startX,startY, 0.0);
12 poLine->setPoint(1,endX,endY, 0.0);
13
14 poFeature->SetGeometryDirectly( poLine );
15 if( poLayer->CreateFeature( poFeature ) != OGRERR_NONE )
16 {
17     AfxMessageBox("Failed to create feature in shapefile.");
18     return FALSE;
19 }
（7）资源清理
1 OGRDataSource::DestroyDataSource( poDS );
2 OGRCleanupAll();