這些代碼要寫在iframe頁中執行

    <script type="text/javascript">
        $(function () {
            // Firefox和Chrome早期版本中帶有前綴
            var MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver
            // 選擇目標節點
            var target = document.body;
            
 
// 創建觀察者對象
            var observer = new MutationObserver(function (mutations) {
                setIframeByElement(getIframeByElement(document.body))
            });
            // 配置觀察選項:
            var config = { attributes: true, subtree: true }
            // 傳入目標節點和觀察選項
            observer.observe(target, config);
            
 
// 隨後,你還可以停止觀察
            //observer.disconnect();

        });
        function setIframeByElement(iFrame) {
            $(iFrame).attr(‘height‘, $(iFrame).contents().find("body").height() + ‘ !important‘);
        }

        function getIframeByElement(element) {
            var iframe;
            $(
 
"iframe", window.parent.document).each(function () {
                if (element.ownerDocument === this.contentWindow.document) {
                    iframe = this;
                }
                return !iframe;
            });
            return iframe;
        }
    </script>

H5特性 MutationObserver 監聽元素 動態改變iframe高度