Google Map API in as3, StyledMapType

Question

I having null reference exception when instantiating StyledMapType

var styles:Array = [
new MapTypeStyle(
MapTypeStyleFeatureType.ALL,
MapTypeStyleElementType.ALL,
[
MapTypeStyleRule.visibility( "on" ),
MapTypeStyleRule.hue( 0xff0000 ),
MapTypeStyleRule.saturation( 100 ),
MapTypeStyleRule.lightness( -50 ),
MapTypeStyleRule.gamma( 1.0 )
]
)
];

var options:StyledMapTypeOptions = new StyledMapTypeOptions( {
name: 'Styled map',
alt: 'Style',
minResolution: 2,
maxResolution: 12
});

var styledMapType:StyledMapType = new StyledMapType(styles, options);

I am getting this error:

TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at com.google.maps::StyledMapType()
    at com::Main/init()
    at com::Main()

But when I omit this line:

var styledMapType:StyledMapType = new StyledMapType(styles, options);

the program runs.

Answer 1

You need to register an event listener on MAP_READY and put this code in your listener. The error is probably happening because your google map object is not fully instantiated yet.

public function somefunction(): void
{
    yourGoogleMapobject.addEventListener(MapEvent.MAP_READY, onMapReady);
}

private function onMapReady(event:Event):void
{
    var styles:Array = [
    new MapTypeStyle(
    MapTypeStyleFeatureType.ALL,
    MapTypeStyleElementType.ALL,
    [
    MapTypeStyleRule.visibility( "on" ),
    MapTypeStyleRule.hue( 0xff0000 ),
    MapTypeStyleRule.saturation( 100 ),
    MapTypeStyleRule.lightness( -50 ),
    MapTypeStyleRule.gamma( 1.0 )
    ]
    )
    ];

    var options:StyledMapTypeOptions = new StyledMapTypeOptions( {
    name: 'Styled map',
    alt: 'Style',
    minResolution: 2,
    maxResolution: 12
    });

    var styledMapType:StyledMapType = new StyledMapType(styles, options);
}