private static string GetNextEmptyOrOpener(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
string nextWord = tokenizer.GetStringValue();
if (nextWord == "EMPTY" || nextWord == "(")
{
return(nextWord);
}
throw new Exception("Expected 'EMPTY' or '(' but encountered '" + nextWord + "'");
}
private static Point ReadPointText(WktStreamTokenizer tokenizer)
{
Point p = new Point();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(p);
}
p.X = GetNextNumber(tokenizer);
p.Y = GetNextNumber(tokenizer);
GetNextCloser(tokenizer);
return(p);
}
private static GeometryCollection ReadGeometryCollectionText(WktStreamTokenizer tokenizer)
{
GeometryCollection geometries = new GeometryCollection();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken.Equals("EMPTY"))
{
return(geometries);
}
geometries.Collection.Add(ReadGeometryTaggedText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken.Equals(","))
{
geometries.Collection.Add(ReadGeometryTaggedText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(geometries);
}
private static MultiPoint ReadMultiPointText(WktStreamTokenizer tokenizer)
{
MultiPoint mp = new MultiPoint();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(mp);
}
mp.Points.Add(new Point(GetNextNumber(tokenizer), GetNextNumber(tokenizer)));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
mp.Points.Add(new Point(GetNextNumber(tokenizer), GetNextNumber(tokenizer)));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(mp);
}
private static MultiLineString ReadMultiLineStringText(WktStreamTokenizer tokenizer)
{
MultiLineString lines = new MultiLineString();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(lines);
}
lines.LineStrings.Add(ReadLineStringText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
lines.LineStrings.Add(ReadLineStringText(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(lines);
}
private static Geometry ReadGeometryTaggedText(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
string type = tokenizer.GetStringValue().ToUpper();
Geometry geometry = null;
switch (type)
{
case "POINT":
geometry = ReadPointText(tokenizer);
break;
case "LINESTRING":
geometry = ReadLineStringText(tokenizer);
break;
case "MULTIPOINT":
geometry = ReadMultiPointText(tokenizer);
break;
case "MULTILINESTRING":
geometry = ReadMultiLineStringText(tokenizer);
break;
case "POLYGON":
geometry = ReadPolygonText(tokenizer);
break;
case "MULTIPOLYGON":
geometry = ReadMultiPolygonText(tokenizer);
break;
case "GEOMETRYCOLLECTION":
geometry = ReadGeometryCollectionText(tokenizer);
break;
default:
throw new Exception(String.Format(Map.NumberFormatEnUs, "Geometrytype '{0}' is not supported.",
type));
}
return(geometry);
}
/// <summary>
/// 取得多边形区域文字
/// </summary>
/// <param name="tokenizer"></param>
/// <returns></returns>
private static Polygon ReadPolygonText(WktStreamTokenizer tokenizer)
{
Polygon pol = new Polygon();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(pol);
}
pol.ExteriorRing = new LinearRing(GetCoordinates(tokenizer));
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
//Add holes
pol.InteriorRings.Add(new LinearRing(GetCoordinates(tokenizer)));
nextToken = GetNextCloserOrComma(tokenizer);
}
return(pol);
}
private static MultiPolygon ReadMultiPolygonText(WktStreamTokenizer tokenizer)
{
MultiPolygon polygons = new MultiPolygon();
string nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(polygons);
}
Polygon polygon = ReadPolygonText(tokenizer);
polygons.Polygons.Add(polygon);
nextToken = GetNextCloserOrComma(tokenizer);
while (nextToken == ",")
{
polygon = ReadPolygonText(tokenizer);
polygons.Polygons.Add(polygon);
nextToken = GetNextCloserOrComma(tokenizer);
}
return(polygons);
}
private static double GetNextNumber(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
return(tokenizer.GetNumericValue());
}
private static LineString ReadLineStringText(WktStreamTokenizer tokenizer)
{
return(new LineString(GetCoordinates(tokenizer)));
}
public static Geometry Parse(TextReader reader)
{
WktStreamTokenizer tokenizer = new WktStreamTokenizer(reader);
return(ReadGeometryTaggedText(tokenizer));
}
