ENVIView::GetLayer

The GetLayer function method returns the top-most layer in the view. The supported layers are:

Example

; Launch the application

e = ENVI()

; Open a file

file = FILEPATH('qb_boulder_msi', ROOT_DIR=e.ROOT_DIR, $

  SUBDIRECTORY = ['data'])

; Create an ENVIRaster

raster = e.OpenRaster(file)

; Create two ENVIRasterLayers

view = e.GetView()

layer1 = view.CreateLayer(raster)

layer2 = view.CreateLayer(raster, /CIR)

; Move layer1 to the top of the layer manager

layer1.MoveToTop

; Get the top-most layer and print bands

layer = view.GetLayer()

PRINT, layer.BANDS

Syntax

Result = ENVIView.GetLayer([, Keywords=value])

Return Value

This function returns a view's top-most layer. This can be an ENVIAnnotationLayer, ENVIGridLinesLayer, ENVIRasterLayer, ENVIRasterSeriesLayer, or ENVIVectorLayer.

Keywords

Keywords are applied only during the initial creation of the object.

ALL

When this keyword is set, the method returns an array of all layers in top-down order (as they are listed in the Layer Manager).

ERROR

Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.

When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.

See Manage Errors for more information on error handling in ENVI programming.

Version History

ENVI 5

Introduced

API Version

4.2