private void PrepareTable(DataTable table)
{
DataColumn shapeColumn = null;
foreach (DataColumn column in table.Columns)
{
if (column.DataType.GetInterfaces().Contains(typeof(IGeometry)))
{
shapeColumn = column;
switch (shapeColumn.DataType.Name)
{
case "IPoint":
_shapeType = 1;
break;
case "IMultiLineString":
_shapeType = 3;
break;
case "IMultiPolygon":
_shapeType = 5;
break;
}
}
}
if (shapeColumn == null)
{
throw new ArgumentException("Table does not contain a shape column");
}
_table = table;
_shapeColumn = shapeColumn;
_shapeLength = new int[_table.Rows.Count];
_numParts = new int[_table.Rows.Count];
_numPoints = new int[_table.Rows.Count];
for (int i = 0; i < _table.Rows.Count; ++i)
{
if (_table.Rows[i].IsNull(_shapeColumn))
{
_shapeLength[i] = 2;
}
else
{
IGeometry geometry = (IGeometry)_table.Rows[i][_shapeColumn];
switch (_shapeType)
{
case 1:
_shapeLength[i] = 10;
break;
case 3:
IMultiLineString multiLineString = (IMultiLineString)geometry;
_numParts[i] = multiLineString.Count;
_numPoints[i] = 0;
foreach (ILineString lineString in multiLineString.Geometries.Cast<ILineString>())
{
_numPoints[i] += lineString.Coordinates.Length;
}
_shapeLength[i] = 22 + 2 * _numParts[i] + 8 * _numPoints[i];
break;
case 5:
IMultiPolygon multiPolygon = (IMultiPolygon)geometry;
_numParts[i] = multiPolygon.Count;
_numPoints[i] = 0;
foreach (IPolygon polygon in multiPolygon.Geometries.Cast<IPolygon>())
{
_numPoints[i] += polygon.ExteriorRing.Coordinates.Length;
}
_shapeLength[i] = 22 + 2 * _numParts[i] + 8 * _numPoints[i];
break;
}
_extent.ExpandToInclude(geometry.EnvelopeInternal);
}
_fileLength += _shapeLength[i] + 4;
}
_dbf = new DBaseWriter(_table);
}