登录界面：姐姐点击登录后界面疯狂闪动的问题

(cherry picked from commit a79f1452b30f89983f153699e7183b202c18d50d)

src/views/Login/components/LoginForm.vue

@@ -231,6 +231,7 @@ const getCookie = () => {
     }
   }
 }
+const loading = ref() // ElLoading.service 返回的实例
 // 登录
 const handleLogin = async (params) => {
   loginLoading.value = true
@@ -245,7 +246,7 @@ const handleLogin = async (params) => {
     if (!res) {
       return
     }
-    ElLoading.service({
+    loading.value = ElLoading.service({
       lock: true,
       text: '正在加载系统中...',
       background: 'rgba(0, 0, 0, 0.7)'
@@ -265,13 +266,9 @@ const handleLogin = async (params) => {
     } else {
       push({ path: redirect.value || permissionStore.addRouters[0].path })
     }
-  } catch {
-    loginLoading.value = false
   } finally {
-    setTimeout(() => {
-      const loadingInstance = ElLoading.service()
-      loadingInstance.close()
-    }, 400)
+    loginLoading.value = false
+    loading.value.close()
   }
 }