One of the parameters is invalid as3 - actionscript-3

Question

How To Fix One of the parameters is invalid as3?
First click bitnmap to show maps = OK
Maps + closebtnmap => show ,btn maps => hide
click closebtnmap to hide maps = OK
Second click btnmap to show maps = ERORR
CODE:
import flash.media.StageWebView;
import flash.events.MouseEvent;
import flash.events.Event;
var _webView:StageWebView = new StageWebView();
btnmap.addEventListener(MouseEvent.MOUSE_UP, addWebView);
function addWebView(e:MouseEvent):void
{
_webView.viewPort = new Rectangle(0, 170, 480,510);
_webView.stage = this.stage;
_webView.loadURL("https://goo.gl/maps/b6lMB");
btnclosemap.visible =true;
btnclosemap.addEventListener(MouseEvent.CLICK, closeWebView);
}
function closeWebView(e:MouseEvent):void
{
_webView.stage = null;
_webView.dispose();
btnclosemap.visible =false;
}
ERROR :
ArgumentError: Error #2004: One of the parameters is invalid.
at flash.media::StageWebView/set viewPort()
at sanggaluri_fla::plokasi_27/addWebView()[sanggaluri_fla.plokasi_27::frame1:29]

Answer 1

Your issue is likely because in the closeWebView method, you dispose the StageWebView called _webView.
So now, when you click a second time and addWebView runs, you try to set it's viewport, but the web view has been disposed and so it throws the error.
To make it work, create a new StageWebView inside your addWebView method.
So:
var _webView:StageWebView; //don't instantiate it here
btnmap.addEventListener(MouseEvent.MOUSE_UP, addWebView);
btnclosemap.addEventListener(MouseEvent.CLICK, closeWebView);
function addWebView(e:MouseEvent):void
{
if(!_webView){
_webView = new StageWebView(); //Create a new one here if it doesn't exist / is null
}
_webView.viewPort = new Rectangle(0, 170, 480,510);
_webView.stage = this.stage;
_webView.loadURL("https://goo.gl/maps/b6lMB");
btnclosemap.visible =true;
}
function closeWebView(e:MouseEvent):void
{
_webView.stage = null;
_webView.dispose();
_webView = null; //make it null so you know it's been disposed
btnclosemap.visible =false;
}