28个常用JavaScript方法集锦(6)

function StringBuilder() {
    this.strings = new Array;
};
StringBuilder.prototype.append = function (str) {
    this.strings.push(str);
};
StringBuilder.prototype.toString = function () {
    return this.strings.join('');
};

/* JS 加载到顶部LoadJS  */

复制代码 代码如下:

function loadJS (url, fn) {
        var ss = document.getElementsByName('script'),
            loaded = false;
        for (var i = 0, len = ss.length; i < len; i++) {
            if (ss[i].src && ss[i].getAttribute('src') == url) {
                loaded = true;
                break;
            }
        }
        if (loaded) {
            if (fn && typeof fn != 'undefined' && fn instanceof Function) fn();
            return false;
        }
        var s = document.createElement('script'),
            b = false;
        s.setAttribute('type', 'text/javascript');
        s.setAttribute('src', url);
        s.onload = s.onreadystatechange = function () {
            if (!b && (!this.readyState || this.readyState == 'loaded' || this.readyState == 'complete')) {
                b = true;
                if (fn && typeof fn != 'undefined' && fn instanceof Function) fn();
            }
        };
        document.getElementsByTagName('head')[0].appendChild(s);
    },
    bind: function (objId, eventType, callBack) {  //适用于任何浏览器的绑定
        var obj = document.getElementById(objId);
        if (obj.addEventListener) {
            obj.addEventListener(eventType, callBack, false);
        }
        else if (window.attachEvent) {
            obj.attachEvent('on' + eventType, callBack);
        }
        else {
            obj['on' + eventType] = callBack;
        }
    }
function JSLoad (args) {
        s = document.createElement("script");
        s.setAttribute("type", "text/javascript");
        s.setAttribute("src", args.url);
        s.onload = s.onreadystatechange = function () {
            if (!s.readyState || s.readyState == "loaded" || s.readyState == "complete") {
                if (typeof args.callback == "function") args.callback(this, args);
                s.onload = s.onreadystatechange = null;
                try {
                    s.parentNode && s.parentNode.removeChild(s);
                } catch (e) { }
            }
        };
        document.getElementsByTagName("head")[0].appendChild(s);
    }

/*  清空 LoadJS 加载到顶部的js引用  */

复制代码 代码如下: