为什么用h5+的版本更新，期间不能清除缓存？

plus.nativeUI.confirm(
"当前有新版本是否更新?",
(e) => {
if (e.index === 0) {
var u = navigator.userAgent,
app = navigator.appVersion;
var isIOS = !!u.match(/(i[^;]+;( U;)? CPU.+Mac OS X/); // ios
if (isIOS) {
plus.runtime.openURL(
"https://apps.apple.com/cn/app"
);} else {
localStorage.removeItem("user");
that.downWgt();
}
}
console.log(e, e.index == 0 ? "Yes!" : "No!");
},
"版本更新",
["确定", "取消"]
);
}