Trying to add keyboard events to a child movieclip I call to the stage in code - actionscript-3

Question

So this is my first semester in school coding and right now I'm trying to make a little 2D game with a character who I need to move up and down.
So far, I've been able to create a titlescreen and then when you click start it goes to the next screen, where my main character is.
I add him to the stage manually through the code, and then I tried to make him move up down left and right with the arrow keys but he only appears, and does not move.
This is my code so far
package lib.fly
{
import flash.display.MovieClip;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.events.KeyboardEvent;
import flash.ui.Keyboard;
public class FlyGame extends MovieClip
{
public var mainCharacter:MovieClip;
public var vx:Number;
public var vy:Number;
public function FlyGame()
{
trace ("Initiate");
init();
}
private function init():void
{
vx = 0;
vy = 0;
addEventListener(Event.ENTER_FRAME, onEnterFrame);
stage.addEventListener(KeyboardEvent.KEY_DOWN, moveAround);
stage.addEventListener(KeyboardEvent.KEY_UP, dontMove);
//var dx:Number = speed* Math.cos(angle);
//var dy:Number = speed* Math.sin(angle);
trace ("Keyboard Event Listeners");
}
private function moveAround(event:KeyboardEvent):void
{
trace ("Actual Keyboard Events");
if (event.keyCode == Keyboard.LEFT)
{
vx = -5;
}
else if (event.keyCode == Keyboard.RIGHT)
{
vx = 5;
}
else if (event.keyCode == Keyboard.UP)
{
vy = - 5;
}
else if (event.keyCode == Keyboard.DOWN)
{
vy = 5;
}
}
private function dontMove(event:KeyboardEvent):void
{
if (event.keyCode == Keyboard.LEFT || event.keyCode == Keyboard.RIGHT)
{
vx = 0;
}
else if (event.keyCode == Keyboard.UP || event.keyCode == Keyboard.DOWN)
{
vy = 0;
}
}
public function onEnterFrame(event:Event):void
{
mainCharacter = new BoyFlying();
mainCharacter.x = 20;
mainCharacter.y = 150;
mainCharacter.x += vx;
mainCharacter.y += vy;
addChild(mainCharacter);
}
}
}
The output produces the trace statements up until my "Actual Keyboard Events"
Sorry, I'm brand new to this so any help would be appreciated. Thank you for your time

Answer 1

Try this logic below and see if it helps your program to work as expected...
Adjust function init()
private function init():void
{
vx = vy = 0; //chain them since same value
mainCharacter = new BoyFlying(); //create once here and control in other functions
mainCharacter.x = 20;
mainCharacter.y = 150;
mainCharacter.addEventListener(Event.ENTER_FRAME, onEnterFrame);
addChild(mainCharacter);
stage.addEventListener(KeyboardEvent.KEY_DOWN, moveAround);
//stage.addEventListener(KeyboardEvent.KEY_UP, dontMove); //what is it good for?
trace ("added... Keyboard Event Listeners");
//var dx:Number = speed* Math.cos(angle);
//var dy:Number = speed* Math.sin(angle);
}
Adjust function moveAround()
private function moveAround(event:KeyboardEvent):void
{
trace ("Actual Keyboard Events");
if (event.keyCode == Keyboard.LEFT)
{ vx -= 5; }
if (event.keyCode == Keyboard.RIGHT)
{ vx += 5; }
if (event.keyCode == Keyboard.UP)
{ vy -= 5; }
if (event.keyCode == Keyboard.DOWN)
{ vy += 5; }
}
Adjust function onEnterFrame()
public function onEnterFrame(event:Event):void
{
//# no need for += here since function moveAround() changes these vx and vy values on key press
//# infact your character could be moved (x/y) just by keyboard event instead of per FPS screen update (eg: not with EnterFrame)
mainCharacter.x = vx;
mainCharacter.y = vy;
}