View.Area Property
Gets or sets the geographic area displayed in the View.
Syntax
public Rectangle Area { get; set; }Property Value
Default: Differs depending on type. See the table below.
The geographic area displayed in the view, defined in the coordinate reference system of the view.
Default values
| Class | Default value |
|---|---|
| GlobeView | Not used. |
| View | Rectangle.Empty |
Remarks
This property controls the geographic area that will be shown in the view. Several other properties, like Center, Width, Scale and NominalScale, also affect the view area and indirectly this property. For instance, changing the Center property will also change the Area property and vice versa.
If the aspect ratio of the area does not match the aspect ratio of the drawable, the height of the area is normally adjusted so that the ratios match. With the ViewAreaMode property, it is possible to specify that the area should not be adjusted; instead the map should be stretched to fit the drawable.
Depending on the StartPosition property, the view area may initially be adjusted to the bounds of the datasets in the view.
Note that the specified view area is not affected by the Rotation property. If a rotation is specified, areas that are outside the specified view area may become visible.
If the coordinate reference system of the view uses a cylindrical projection like Mercator, Miller or LongLat, then the X coordinates of the area corners are not always normalized.
For example, if the coordinate reference system is Crs.Wgs84LongLat, then a normalized X coordinate should be a longitude between -180° and +180°. But if you pan east to show the Fiji islands, say with a width of 10°, then the area may have Xmin = +173° and Xmax = +183°, so that Xmax is outside the normal range. And if you then pan 10 degrees further east, the area will get Xmin = +183° and Xmax = +193°, so that it is completely outside the normal range.
An area with non-normalized corners is usually harmless, but if your application code reads the area property from the view, you may need to handle non-normalized corners, for example via the Crs.NormalizeCyclicEasting method.
Example
// View the whole world in a 2D View
public static void ViewWholeWorld(View view)
{
// The bounding coordinates of the whole world in Wgs84LongLat
Rectangle wholeWorld = new Rectangle(-180, -90, 180, 90);
// Project the bounding coordinates to the Crs of the View
wholeWorld = Crs.Wgs84LongLat.ProjectTo(view.Crs, wholeWorld).Bounds;
// Set the Area of the View to the whole world
view.Area = wholeWorld;
// Update the View
view.Update();
}
Platforms
Windows, Linux, Android