字符统计

关于 onpropertychange 和 oninput

HTML

<h3 class="pro_h3 pt_20">标题<span>(<b id="news_title_limit">0</b>/30字)</span></h3>
<input class="input_text" type="text" name="news_title" id="news_title" value="好呀！" />

CSS

.pro_h3{
    font-size:20px;
    font-family:"微软雅黑";
    color:#115f8e;
}

.pro_h3{
    font-size:16px;
    color:#888;
    font-weight:bolder;
    padding-bottom:5px;
}

.pro_h3 span{
    font-size:12px;
    font-weight:normal;
    margin-left:5px;
}

.pro_h3 b{    font-weight:normal;}

.input_text{
    width:300px;
    border:1px solid #CCC;
    padding:8px;
    font-family:"微软雅黑";
    font-size:14px;
    color:#454545;
    background-color:#f6f6f6;
    
    box-shadow:inset 0 1px 1px rgba(0,0,0,0.1);
    -moz-box-shadow:inset 0 1px 1px rgba(0,0,0,0.1);
    -webkit-box-shadow:inset 0 1px 1px rgba(0,0,0,0.1);
}

JavaScript

/*
                    参数： 
                    length:最大长度        
                    ele: 输入对象        
                    callBack： 回调方法，参数len表示当前输入框内容字节数， 方法中的this指向ele对
                    autoFire:   初使化自动调用一次
                */
                function input_max(length, ele, showEle, callBack,autoFire){
                    
                    if(ele.addEventListener){
                        //ele.addEventListener('input', change, false);
                        ele.addEventListener('focus', intervalChange, false);
                        ele.addEventListener('blur', function(){clearInterval(this.dataFocus); delete this.dataFocus}, false);

                    }else{
                        //ele.attachEvent('onpropertychange', function(){if(window.event.propertyName == "value"){alert('a');change()}})
                        ele.attachEvent('onfocus', intervalChange);
                        ele.addEventListener('onblur', function(){clearInterval(this.dataFocus); delete this.dataFocus});

                    }
                    
                    function intervalChange(){
                       this.dataFocus = setInterval(change,200);
                    }
                    
                    function change(){
                            var len = Math.ceil(byteLength(ele.value)/2);
                            len = len <= length ? len : length - len;
                            callBack.call(ele,showEle,len); 
                    };
                    
                    function byteLength(b) {
                        if (typeof b == "undefined") { return 0 }
                        var a = b.match(/[^\x00-\x80]/g);
                        return (b.length + (!a ? 0 : a.length))
                    };
                    
                    //自动调用一次
                    if(autoFire){change()};
                    
                };


                // 回调函数
                function input_max_callBack(showEle,len){
                    var...