Hello all, I have another itch.

I want to place a rectangle shape on a map and afterwords get te coordinates for the TopLeft corner and the BottomRight one since my code handles these coordinates rather than the location width and hight.
I have no problem drawing the rectangle it is with the coordinates where I am stuck Ihave seen the vertices property in the shape namespace but it returns an object type and I have done some testing but cant make any sesnce.

Any sugestions?.
thanks

I'm not sure I understand the issue but here's some information..

Vertices is an array of Location objects.. see the Vertices Property in the Help File... here is the example code:

Code:

  Sub CreateTwoShapes()
 
  Dim objApp As New MapPoint.Application
  Dim objMap As MapPoint.Map
  Dim objLoc(1 To 3) As MapPoint.Location
 
  'Set up the application
  Set objMap = objApp.ActiveMap
  objApp.Visible = True
  objApp.UserControl = True
 
  'Get three locations and zoom in, and then create a shape
  Set objLoc(1) = objMap.FindResults("Seattle, WA").Item(1)
  Set objLoc(2) = objMap.FindResults("Redmond, WA").Item(1)
  Set objLoc(3) = objMap.FindResults("Tacoma, WA").Item(1)
  Set objMap.Location = objLoc(1)
  objMap.Shapes.AddPolyline objLoc
 
  'Use the vertices of this shape to create another shape
  objMap.Shapes.AddPolyline objMap.Shapes.Item(1).Vertices
  MsgBox "There are now " + CStr(objMap.Shapes.Count) + " shapes."
 
  End Sub

To get at the location items, Lat/Lon's, I think the syntax would be like this:

objMap.Shapes.Item(1).Vertices(1).Longitude
objMap.Shapes.Item(1).Vertices(1).Latitude
objMap.Shapes.Item(1).Vertices(2).Longitude
....

What language are you coding in?

Erc

The rectangle object (rather than a freeform like I think Eric is describing) is defined in terms of width and height. Unfortunately the exact way this maps to the Earth's surface depends on your current map view. It will change!

My solution is to extrapolate from the centre coordinate and accept that it might not quite match at the edges/corners all the time. Another solution would be to play with screen coordinates. This would more accurately match the on-screen representation although it would rely on the rectangle being fully on the screen all the time.


Also because the Earth is a sphere, you need multiple points on each edge to get a decent representation. I find 3 or 4 (rather than 2: 1 per corner) works pretty well.

Richard

Sorry Eric, for the delay I have been traveling,

thanks for the answer, but what I need is to draw a shape on the map a rectangle not using a collection of locations. The user will draw the shape with the map point drawing tool.

once the shape is drawn I need to get the vertices, as I have tested them before if the shape vertices do not meet with any other object in the dataset I get no information on the vertices. on your example you actualy define the vertices form locations or places, but I have none of this

I need to store the upper left corner and the bottom right corner, I use this information on a GPS Tracking device that uses it as a POI or GeoFence reference.

I was thinking in using a little math with some help from pitagoras and the circle law but I was wondering if anybody had a snippet to reuse and avoid reworking known algorithms.

I am currentlly coding in VB.Net on VS 2008 but anithing in C, C++ or C# will be ok.


Brgds
Ian.

PS. I got the a note from the post office so I guess it will be the book I ordered.

Thank Richard,

I will have a try at the screen points since my rectangle has to be completey in the screen when the cilent has finished drawing it. thanks for the tip. seems easyer to do than all the other maths.

Wonder why MS dosent pull the Lat/Lon for every object or object vertice on the map ?? as you say it is only drawing logic.

brgds
Ian.