Flash Pro Hyperlink button error

问题

I have created a button using flash Pro cc I've been doing research but was unable to find why a TypeError stating

TypeError: Error #1009: Cannot access a property or method of a null object reference.at PD3Subscribenow_fla::MainTimeline/frame1()

I have placed my code on a action layer on frame 1:

import flash.events.MouseEvent;
sub_btn.addEventListener(MouseEvent.CLICK, myButtonFunction);
function myButtonFunction(event: MouseEvent) {
var request:URLRequest = new URLRequest("http//:www.google.com");
navigateToURL(request, "_blank");
}

and gave the instance name of my button "sub_btn".

Can you tell me where I have gone wrong.

回答1:

You issue is that on the frame where the code executes, sub_btn does not yet exist (as you state in your comments that it is on a later frame).

You either need to:

1. Move the button to the first frame,

or

2. Move the code that references it to the frame with the button.

回答2:

The problem maybe that Flash does not recognize that your button exists yet. In Flash Builder I would use

 creationComplete="init()"

and then

 private function init():void{
    sub_btn.addEventListener(MouseEvent.CLICK, myButtonFunction)
 }

来源：https://stackoverflow.com/questions/26995720/flash-pro-hyperlink-button-error