This section provides information about the basic concepts such as visibility and coordinate systems in Map control.

Visibility

The portion of the map that is currently visible is determined by the Center and Zoom properties, and by the size of the control:

• The Center property is of type Point but it actually represents a geographic coordinate in which the X property is longitude and the Y property is latitude. The user can change the value of the Center property by dragging the map with the mouse, or by using the navigator control shown on the left top corner.
• The Zoom property indicates the current resolution of the map. A zoom value of 0 has the map totally zoomed out, and each increment of 1 doubles the map resolution. The user can change the value of the Zoom property using the mouse wheel or the zoom control on the left side of the control.

Coordinate Systems

The Map control uses three coordinate systems:

• Geographic coordinates mark points in the world using latitude and longitude. This coordinate system is not Cartesian, which means the scale of the map may change as you pan.
• Logical coordinates go from 0 to 1 on each axis for the whole extent of the map, and they are easier to work with because they are Cartesian coordinates.
• Screen coordinates are the pixel coordinates of the Control relative to the top-left corner. These are useful for positioning items within the control and for handling mouse events.