和 TextField 相关的文章

//Copyright © 2009. Http://L4cd.Net All Rights Reserved.
package net.L4cd.display
{
	import flash.events.Event;
	import flash.events.TextEvent;
	import flash.text.TextField;
	import flash.utils.ByteArray;

	/**
	 * 扩展TextField类,中文以2字符长度计算
	 *
	 * @author L4cd.Net
	 * @playerversion Flash player 9
	 * @langversion 3.0
	 * @version 2009-06-16
	 */
	public class TextFieldExt extends TextField
	{
		private var _maxChars:int = -1;
		public function TextFieldExt()
		{
			super();
			
		}
		override public function get maxChars():int
		{
			return _maxChars;
		}
		override public function set maxChars(value:int):void
		{
			_maxChars = value;
			if(maxChars<0)
			{
				removeEventListener(TextEvent.TEXT_INPUT,input);      
			}else
			{
				addEventListener(TextEvent.TEXT_INPUT,input);
				text = getTextByCharLength(text,maxChars);
			}
		}
		override public function get length():int
		{
			return getCharLength(text);
		}
		private function input(e:TextEvent):void
		{
			//拦截并阻止textinput事件,手动处理内容输入
			var textField:TextField = e.currentTarget as TextField;
			var temp:String = getTextByCharLength(e.text,maxChars - getCharLength(text) + getCharLength(selectedText));
			var index:int = selectionBeginIndex;
			replaceText(selectionBeginIndex,selectionEndIndex,temp);
			setSelection(index+temp.length,index+temp.length);
			dispatchEvent(new Event(Event.CHANGE,true));
			e.preventDefault();
		}
		/**
		 * 获取字符长度,一个中文算2长度
		 * @param txt
		 * @return 返回长度值
		 */    
		private function getCharLength(txt:String):int
		{
			var byte:ByteArray = new ByteArray();
			byte.writeMultiByte(txt,"gb2312");
			byte.position = 0;
			return byte.bytesAvailable;
		}
		/**
		 * 截取指定长度的文本内容,一个中文算2长度
		 * @param txt 需要截取的文本
		 * @param length 需要截取的长度
		 * @return 截取后的内容
		 */    
		private function getTextByCharLength(txt:String,length:int):String
		{
			if(length<1)return "";
			var byte:ByteArray = new ByteArray();
			byte.writeMultiByte(txt,"gb2312");
			byte.position = 0;
			return byte.readMultiByte(Math.min(length,byte.bytesAvailable),"gb2312");
		}
	}
}

var txt:TextField = new TextField();
txt.x = 10;
txt.y = 10;
txt.autoSize = "left";
txt.selectable = false;
txt.htmlText = "<a href='event:#'>显示手形的TextField</a>";
addChild(txt)