优化

src/components/home.vue

@@ -219,8 +219,10 @@ export default ({
             if(data=='quit_class'){
 
                 //消失线
-                lineContainer.value.remove()
-                lineContainer.value = null
+                if (lineContainer.value) {
+                    lineContainer.value.remove()
+                    lineContainer.value = null
+                }
                 //消失点击详情
                 popoverRef.value.style.display = "none"
                 //消失面板