JavaScript Javascript警告用户如果他们离开此页面他们将丢失数据

Posted 2021-05-20

function setConfirmUnload(on) {
            window.onbeforeunload = (on) ? unloadMessage : null;
        }
        function unloadMessage() {
            return 'You have entered new data on this page.  If you navigate away from this page without first saving your data, the changes will be lost.';
        }