新消息提醒机制，调整为uni.$emit全局事件，网络状态变化亦然

pages/im/index.vue

@@ -101,8 +101,19 @@
                 }
             }
         },
+        onLoad() {
+            if (this.isShown) {
+                uni.$on('onReceiveMessage', (msg) => {
+                    console.log(msg);
+                    this.getConversationList()
+                })
+                uni.$on('onConnectionStatusChange', (status) => {
+                    this.connection = status
+                })
+            }
+        },
         onShow() {
-            if (this.$store.state.token !== '') {
+            if (this.$store.state.token !== '') {
                 this.getConversationList()
             }
             this.isShown = true
@@ -125,16 +136,6 @@
                 }
             }
         },
-        watch: {
-            '$store.getters.newMessage': function(n, o) {
-                if (this.isShown) {
-                    this.getConversationList()
-                }
-            },
-            '$store.getters.connection': function(n, o) {
-                this.connection = n
-            }
-        },
         methods: {
             hidePop() {
                 this.showPop = false