[AS3] Dynamically create border around MovieClips in Flash using ActionScript

While working on a project, I needed to highlight the selected thumbnail of an image, and this is how I added border dynamically to that MovieClip. Follow these steps before adding the AS3 code:

1. Draw a rectangle on stage and convert it into a new MovieClip by selecting it and pressing F8.
2. Name it a “Box” and check the box Export for Action Script
3. Close the MovieClip now, we are done with the drawing here.

Add this AS3 code on the first frame in Actions Panel:

//let's create a function to add borders

function addBorder(myMC):void{
	
var mc:MovieClip = new MovieClip();
mc.graphics.lineStyle(2, 0x434B54);
mc.graphics.drawRect(0, 0, myMC.width/2+105, myMC.height/2+20);
mc.graphics.endFill();
myMC.addChild(mc);

  }

//create Box movieClip to attach border

var myBox:Box = new Box();

myBox.width = 300;
myBox.height = 200;

myBox.x = 50;
myBox.y = 100;

//put it on stage
addChild(myBox);

//attach border
addBorder(myBox);

You can add borders to any other MovieClip using the same logic.

Hope that helps.

Cheers!