FDO-Shape file .Net

Hi All,

Today we are going to tell, how to connect and retrive the shape file information through FDO using .net.

• Download the latest version of FDO providers from internet.

• Extract and copy the dll in to your local machine.

• Open the visual studio .net 2005

• Create new c# windows application project.

• Right click on the references and add the following dlls to your project from FDO Bin folder





• Create a new class say “FDOShapeFileClass”
• Below we have shown the code connect and read the shape file geometry


public class FDOShapeFileClass:IDisposable

{
private IProviderRegistry FDORegistry = FeatureAccessManager.GetProviderRegistry();
private IConnectionManager FDOManager = FeatureAccessManager.GetConnectionManager();
private IConnection FDOConnection = FeatureAccessManager.GetConnectionManager().CreateConnection("OSGeo.SHP.3.3"); // Replace the version of DLL your using…
public string OpenedFile;
public ConnectionState Constate;
public FDOShapeFileClass(string _ShapeFile)
{
OpenedFile = _ShapeFile;
FDOConnection.ConnectionInfo.ConnectionProperties.SetProperty("DefaultFileLocation", _ShapeFile);
Constate = FDOConnection.Open();

}

// To check the connection state of the Shape file…

public ConnectionState CheckConnected
{
get
{
return Constate;
}
}



// By using below function we can retrive the all geometry in the shape file at once..
// this function will return the Geomtrycollection… of the shape file.


public GeometryCollection SelectAllQuery()
{
ISelect sel = (ISelect)FDOConnection.CreateCommand(OSGeo.FDO.Commands.CommandType.CommandType_Select);
sel.SetFeatureClassName(System.IO.Path.GetFileNameWithoutExtension(OpenedFile));

IFeatureReader FDOReader = sel.Execute();
GeometryCollection Geo_Collection = new GeometryCollection();
FgfGeometryFactory GeoFac = new FgfGeometryFactory();
while (FDOReader.ReadNext())
{

Byte[] Tmppts = FDOReader.GetGeometry("Geometry");

IGeometry Geo = GeoFac.CreateGeometryFromFgf(Tmppts);
Geo_Collection.Add((IGeometry)Geo);
}
return Geo_Collection;
}

// By using this function we can the extents of shape file in the form of ipolygon.

public IPolygon GetExtents()
{
IPolygon retpolygon;
ISelectAggregates pselagree = (ISelectAggregates)FDOConnection.CreateCommand(CommandType.CommandType_SelectAggregates);
pselagree.SetFeatureClassName(System.IO.Path.GetFileNameWithoutExtension(OpenedFile));

IdentifierCollection props = pselagree.PropertyNames;
Expression exp = Expression.Parse("SpatialExtents(Geometry)");
ComputedIdentifier se = new ComputedIdentifier("Extents", exp);

props.Add(se);

IDataReader FDOReader = pselagree.Execute();
FgfGeometryFactory GeoFac = new FgfGeometryFactory();

FDOReader.ReadNext();
Byte[] Tmppts = FDOReader.GetGeometry("Extents");

IGeometry Geo = GeoFac.CreateGeometryFromFgf(Tmppts);

retpolygon = (IPolygon)Geo;

return retpolygon;

}

// we will give this function in the next post…

public void UpdateQuery()
{
throw new System.NotImplementedException();
}

public void DeleteQuery()
{
throw new System.NotImplementedException();
}

public void Dispose()
{
Close();
FDORegistry.Dispose();
FDOManager.Dispose();
FDOConnection.Dispose();
}

private void Close()
{
FDOConnection.Close();
}


• Based on your feedback in the next post we will tell you how to use this retrived geometry in to your application.


Thank You,