以前写过一个数值文本NumberText,也就是只允许输入数值,而其他文本不允许被输入.NumberText当时是根据判断键盘事件来控制输入的,感觉有点傻,后来知道了TextField本身就有属性来限制输入的字符,就一直想重写下这个数值文本.今天终于有空重新写了个新的数值文本:NumTextField.

文本框其实本身就有TextField.restrict这个属性来限制输入的字符的,所以侦听键盘事件去过滤文本有点多余了.所以今天就重写了NumberText类.

示例

代码

/**
 * NumTextField 继承于  TextField
 * 
 * 禁用的 属性 和方法
 *      override public function set multiline(value:Boolean):void { } 
 *      override public function set type(value:String):void { } 
 *      override public function set text(value:String):void { } 
 *      override public function set htmlText(value:String):void { } 
 *      override public function appendText(newText:String):void { }
 * 
 * 增加的属性
 *      number 可读写  NumberText 的值 
 */

package com.litefeel.controls 
{
    import flash.events.Event;
    import flash.events.TextEvent;
    import flash.text.TextField;

    /**
     * www.litefeel.com
     * lite3@qq.com
     * @author lite3
     */
    public class NumTextField extends TextField
    {
        private var num:Number = 0;
        private var ignoreChange:Boolean = false;

        public function NumTextField() 
        {
            super.restrict = '.0-9';
            super.maxChars = 17;
            super.type = "input";
            super.text = getNumStr();
            super.height = super.textHeight + 4;
            super.wordWrap = false;
            super.multiline = false;
            super.border = true;
            super.addEventListener(Event.CHANGE, changeHandler);
        }

        /**
         * NumTextField的值  可读写
         */
        public function get number():Number { return num; }
        public function set number(value:Number):void
        {
            if (isNaN(value) || value < 0) value = 0;

            num = value;
            super.text = getNumStr();
        }

        // 禁用的方法及函数
        override public function set multiline(value:Boolean):void { } 
        override public function set type(value:String):void { } 
        override public function set text(value:String):void { } 
        override public function set htmlText(value:String):void { } 
        override public function appendText(newText:String):void { }

        private function getNumStr():String
        {
            var s:String = num + "";
            if ( -1 == s.indexOf(".")) s += ".";
            return s;
        }

        private function changeHandler(e:Event):void 
        {
            if (ignoreChange) return;

            var old:Number = num;
            number = parseFloat(text);
            super.text = getNumStr();
            if (old == num) return;

            if (old < 1 && num >= 1
                && selectionBeginIndex == selectionEndIndex
                && text.charAt(selectionBeginIndex-1) == ".")
            {
                setSelection(1, 1);
            }

            ignoreChange = true;
            dispatchEvent(new Event(Event.CHANGE));
            ignoreChange = false;
        }
    }
}