Using MovieClip(root) in ActionScript 3

Question

im at frame 3.. i have text field on the stage name scoreTxt.. at frame 3 i added TryClass..

 var Try:TryClass = new TryClass();

TryClass has function of updateScore.. this is working fine if im on frame 3. so my code is

     public function updateScore(amount:int):void
     {
           score += amount;
           if(score < 0) score = 0;

           realNumber = score;

           setInterval(updateDisplayedScore, 10);

     }

     public function updateDisplayedScore():void
           {
               displayedNumber += Math.round((realNumber-displayedNumber)/5);
               if (realNumber - displayedNumber < 5 && realNumber - displayedNumber > -5)
               {
                     displayedNumber = realNumber;
               }
               addZeros();
           }

     public function addZeros():void
           {
               var str:String = displayedNumber.toString();
               MovieClip(root).scoreNa.text = str;
           }

but then if for example .. the user died or he reaches the required score.. im suppose to go a certain frame using this code..

MovieClip(this.root).gotoAndStop("Main"); this code is on the class..

its reaching the frame "Main" but its pointing errors to this -->

MovieClip(root).scoreTxt.text

that "Main" frame is on frame 4.. which i did not yet added the TryClass.. should i add to all my frames the TryClass? and how is that?

Sorry for the question.. i dont know yet how to perfectly code in the class.. and accessing the timelines and other external class.. Please dont use deeper language of actionscript.. on a beginner way only..

here is the full error message when i go to the frame "Main"

TypeError: Error #1009: Cannot access a property or method of a null object reference.
          atTumba/addZeros()[C:\Documents and Settings\Chrissan\Desktop\Game and Docs\Game\Tumba.as:686]
          atTumba/updateDisplayedScore()[C:\Documents and Settings\Chrissan\Desktop\Game and Docs\Game\Tumba.as:680]
          atFunction/http://adobe.com/AS3/2006/builtin::apply()
          atSetIntervalTimer/onTimer()
          atflash.utils::Timer/_timerDispatch()
          atflash.utils::Timer/tick()

this is the line 686 of Tumba.as - MovieClip(root).scoreNa.text = str;

public function updateDisplayedScore():void
               {
                   displayedNumber += Math.round((realNumber-displayedNumber)/5);
                   if (realNumber - displayedNumber < 5 && realNumber - displayedNumber > -5)
                   {
                         displayedNumber = realNumber;
                   }
                   addZeros(); -->> this is the line 680 of Tumba.as
               }

about the setInterval sir.. its working fine cause i imported the flash.utils.* ..its working fine on frame 3 which i added the class.. but on "Main" fram. it isnt..

i mean scoreNa sir. im sorry.. its not yet fixed.. when im going to the next frame.. it seems its finding where is the scoreNa.text.. because scoreNa.text is only at the frame 3. — Earl Burdeos, Oct 11 '13 at 20:21

score 0 · Answer 1 · answered Oct 15 '13 at 05:28

0

Try using (root as MovieClip) instead of MovieClip(root)

answered Oct 15 '13 at 05:28

Zoron19

594
5
7

score 0 · Answer 2 · answered Jul 27 '15 at 02:59

My guess would be that "root" is undefined, because I'm guessing TryClass is not inherited from a MovieClip or other DisplayObject that lives in the existing heirarchy.

To fix it, I'd add a parameter to the class's constructor. Then, I would send it a movieclip that you can access. For instance, if you are instantiating your class from within a movieclip, just send it the "this" for that movie.

public class TryClass {
   ...
   static var myroot:MovieClip = null;
   ...
   public function TryClass(someclip:MovieClip=null) {
      ...
      if (this.myroot == null && someclip != null && someclip.root != undefined) {
        this.myroot = someclip.root;
      }
      ...
   }
   ...
}

Then from within a movie clip:

var something = new TryClass(this);

Anyway, this is the technique I'm using for a class that I'm making. For mine, I have it adding an instance of an external movie clip if the class detects that the root does not already have it loaded. In my case, a universal loading-bar called from my loading wrapper class. If a particular movie I put it in already has a custom loading bar, then it won't do anything, but for any I don't have one in yet, it'll add it.

Using MovieClip(root) in ActionScript 3

2 Answers2