限制 Flash TextField 輸入字數及行數

監聽 TextEvent.TEXT_INPUT 事件，
超過字數及行數使用 e.preventDefault 取消事件。
完整 code 如下：

	package
	{
	import flash.display.Sprite;
	import flash.events.TextEvent;
	import flash.text.TextField;
	import flash.text.TextFormat;
	public class BaseInput extends Sprite
	{
	private const MAX_NUM_LINES:uint = 3;
	private const MAX_NUM_TXT:uint = 30;
	private var _tf:TextField;
	public function BaseInput(__config:Object)
	{
	var color:Number = 0x3B5998;
	if (__config.color != null) color = Number(__config.color);
	var format:TextFormat = new TextFormat("Microsoft JhengHei", 14, color);
	format.letterSpacing = 1;
	format.leading = 2;
	_tf = new TextField();
	_tf.defaultTextFormat = format;
	_tf.multiline = true;
	_tf.wordWrap = true;
	_tf.selectable = true;
	_tf.type = "input";
	_tf.border = false;
	_tf.width = __config.w;
	_tf.height = __config.h;
	_tf.text = __config.txt;
	addChild(_tf);
	_tf.addEventListener(TextEvent.TEXT_INPUT, inputHandler);
	}
	private function inputHandler(e:TextEvent):void
	{
	/*
	* 換行不計算在內
	*/
	if (_tf.numLines > MAX_NUM_LINES || removeExtraWhitespace(_tf.text).length > MAX_NUM_TXT - 1) {
	// Cancels an event's default behavior
	e.preventDefault();
	}
	}
	// Removes windows-style line breaks
	private function removeExtraWhitespace(p_string:String):String
	{
	if (p_string == null) { return ''; }
	return p_string.replace(/[\r\n]+/g, '');
	}
	}
	}

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