Q:

How to change the height of a TextField?

If I create a TextField in ActionScript 3, I can change the width with a TextFormat, but how do I change the height?
Example:
var label : TextField = new TextField();
label.text = "Hello World!";
label.background = true;
label.backgroundColor = 0x800000;  // Red background to see TextField boundary
label.autoSize = "center";

var format : TextFormat = new TextFormat();
format.leftMargin = 20;
format.rightMargin = 20;

label.setTextFormat( format );

addChild( label );

// Setting the height explicitly doesn't work
label.height = label.width * 1.5;

A:

autoSize is the problem:
label.autoSize = "center"; 

Removing autoSize setting allows you to change the height of textField. If you want to set the alignment, use setTextFormat instead. 
setTextFormat

