將shp文件轉爲GeoJson 文件

GIS內核只有單個feature 轉換,需要添加GeoJson頭,  具體代碼如下:

 

GS_TEST(shp2geojson, metadatatest2, chijiing, 20190322)
{
	GsConnectProperty vConn;
	vConn.Server = u8"D:\\testdata\\3dbuilding";
	vConn.DataSourceType = GsDataSourceType::eGDB;
	GsShpGeoDatabaseFactoryPtr ptrFac = new GsShpGeoDatabaseFactory();
	
	GsGeoDatabasePtr ptrshpGeoDb = ptrFac->Open(vConn);
	GsFeatureClassPtr ptrfcsdst = ptrshpGeoDb->OpenFeatureClass("LoD2_02");
	GsFeatureCursorPtr ptrCursor = ptrfcsdst->Search();
	int nFeaCount = ptrfcsdst->FeatureCount();
	int writerCount = 0;
	GsFeaturePtr ptrFea = ptrCursor->Next();
	GsGeoJSONOGCWriter writer;
	GsVector< GsField> fds = ptrfcsdst->Fields().Fields;
	FILE* fd = fopen("D:\\f2.geojson", "wb+");

	const char* header = "{\"type\": \"FeatureCollection\",\"features\" : [";
	fwrite(header, sizeof(char), strlen(header), fd);


	do
	{	

		writer.Reset();
		if (!ptrFea)
			break;
		writerCount++;
		for(int i = 2; i< fds.size();i++)
		{
			unsigned char* value =  ptrFea->ValuePtr(i);
			double dblHeight = ptrFea->ValueDouble(i);
			
			switch (fds[i].Type)
			{
			case eErrorType:
				continue;
			case eBoolType:
				writer.Attribute(fds[i].Name, *((bool*)value));
				break;
			case eIntType:
				writer.Attribute(fds[i].Name, *((int*)value));
				break;
			case eUIntType:
				writer.Attribute(fds[i].Name, *((unsigned int*)value));
				break;
			case eInt64Type:
				writer.Attribute(fds[i].Name, *((long long*)value));
				break;
			case eUInt64Type:
				writer.Attribute(fds[i].Name, *((unsigned long long*)value));
				break;
			case eStringType:
				writer.Attribute(fds[i].Name, (const char*)value);
				break;
			case eBlobType:
				//m_vecValues[nColumn].Set(value, nSize);
				break;
			case eFloatType:
				writer.Attribute(fds[i].Name, *((float*)value));
				break;
			case eDoubleType:
				writer.Attribute(fds[i].Name, *((double*)value));
				break;
			case eGeometryType:
				//m_vecValues[nColumn] = (GsRefObject*)value;
				break;
			case eDateType:
				writer.Attribute(fds[i].Name,  GsAny(*((long long*)value), true));
			}
			
		}
		writer.Write(ptrFea->Geometry());

		GsString str = writer.GeoJSON().c_str();
		fwrite(str,sizeof(char), str.size(),fd);

		if(writerCount<nFeaCount)
			fwrite(",\t\n", sizeof(char), strlen(",\t\n"), fd);

	}while (ptrCursor->Next(ptrFea));

	const char* endstr = "]}";
	fwrite(endstr, sizeof(char), strlen(endstr), fd);
	fclose(fd);
}