Convert SQL geography to C#

Question

What is the C# equivalent of this geospatial T-SQL code?

DECLARE @g geography;
DECLARE @h geography;
SET @g = geography::STGeomFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326);
SET @h = geography::Point(47.653, -122.358, 4326)

SELECT @g.STIntersects(@h)

I am trying to find a point in a polygon using the SqlGeometry data type -- and can with the above T-SQL; but I do not understand how to achieve equivalent C# code.

Answer 1

Try this:

public bool OneOffSTIntersect()
{
    var g =
        Microsoft.SqlServer.Types.SqlGeography.STGeomFromText(
            new System.Data.SqlTypes.SqlChars(
                "POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))"), 4326);
    // suffix "d" on literals below optional but explicit
    var h = Microsoft.SqlServer.Types.SqlGeography.Point(47.653d, -122.358d, 4326);

    // rough equivalent to SELECT
    System.Console.WriteLine(g.STIntersects(h));

    // Alternatively return from a C# method or property (get).
    return g.STIntersects(h);
}

MSDN's SqlGeography Methods page links to info on each of the C# equivalents to the critical calls in your T-SQL - e.g. STIntersects.