javascript動態創建script標簽,加載完成后調用回調

代碼如下:

        var head = document.getElementsByTagName('head')[0];
        var script = document.createElement('script');
        script.type = 'text/javascript';
        script.charset = 'GBK';
        script.onload = script.onreadystatechange = function() {
            if (!this.readyState || this.readyState === "loaded" || this.readyState === "complete" ) {
                callback();
                script.onload = script.onreadystatechange = null;
            }
        };
        script.src= url;
        head.appendChild(script);

這段代碼實現了動態創建script標簽,然后插入到head標簽中.然后當js加載完畢的時候調用callback回調.

想解釋點什么,但覺得實在沒什么好說的...好吧...就這樣吧...看看就行了...