iframe框架加载完成后执行函数

//方法一
var iframe = document.createElement("iframe");
iframe.src = "http://www.baidu.com/";

if (!/*@cc_on!@*/0) { //if not IE
    iframe.onload = function(){
        alert("框架加载完毕.");
    };
} else {
    iframe.onreadystatechange = function(){
        if (iframe.readyState == "complete"){
            alert("框架加载完毕.");
        }
    };
}

document.body.appendChild(iframe);

//方法二
var iframe = document.createElement("iframe");
iframe.src = "http://www.baidu.com/";

if (iframe.attachEvent){
    iframe.attachEvent("onload", function(){
        alert("Local iframe is now loaded.");
    });
} else {
    iframe.onload = function(){
        alert("Local iframe is now loaded.");
    };
}

document.body.appendChild(iframe);

//应用实例
created() {
        let resTypeId = this.$route.query.resTypeId;
        let resId = this.$route.query.resId;
        const vm = this;
        vm.$http("XXXXXXXXXXX", {
            resTypeId: resTypeId,
            resId: resId,
            previewFlag: 0
        }).then(res => {
            vm.contentlist = res.data.contentList;
            setTimeout(function () {
                var iframes = document.getElementById(‘IFrame‘);
                iframes.src = res.data.contentList[0].contentFileUrl;
                if (! /*@cc_on!@*/ 0) { //if not IE
                    iframes.onload = function () {
                        vm.isloadingsvg = true;//关闭loading
                    }
                } else {
                    iframes.onreadystatechange = function () {
                        if (iframes.readyState == "complete") {
                            vm.isloadingsvg = true;//关闭loading
                        }
                    }
                }
            })
        });
    },