3

I want to create a polygon with csharp 4.5 via DBGeometry class.

I found example on csharp to create a point via System.Data.Spatial namespace. (Requires Reference System.Data.Entity)

This code is working :

var text="POINT(29.11, 40.11)";
DbGeography.PointFromText(text, 4326);  //I can generate a point with this code

But i want to create Polygon object and these codes dont work . Please help me about which prototype - notation should i use to create a polygon or multipolygon object ? And i can not found examples on Microsoft web site. It contains only prototypes, not examples :(

//Not Work
var polyb = DbGeography.MultiPolygonFromText("POLYGON((29.11 40.11, 29.11 40.0 , 29.30 40.0, 29.30 40.11, 29.11 40.11)", 4326); --

//Not Work
//var polyc = DbGeography.MultiPolygonFromText("POLYGON((29.11, 40.11), (29.11, 40.0), (29.30, 40.0), (29.30, 40.11), (29.11, 40.11))", 4326);--

//Not work
//var reVal3 = DbSpatialServices.Default.GeographyPolygonFromText("POLYGON(127.652000002563
-26.244400002062321, 127.652000002563 -26.194399997591972,127.652000002563 -26.244400002062321)", 4326);

Summary How can i create polygon with csharp DBGeometry class from text method ?

8

The DbGeography uses well known text when creating from text

Your last try was almost correct, was missing a '( )' and more points to create an actual polygon, it should be:

System.Data.Spatial.DbGeography.PolygonFromText("POLYGON((127.652 -26.244,127.652 -26.194,[some other points],127.652 -26.244))", 4326);
  • Notice the 2 '(' at each side.
  • Remember that it is Longitude,Latitude and not the other way around like all other places..
  • You must 'close off' the polygon, which means the start point and end point need to be the same
  • +1 for "Remember that it is Longitude,Latitude and not the other way around like all other places.." – Nick Strupat Jun 27 '15 at 23:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.