bug fix

src/pages/im/list/index.js

           pageSize: size,
           pageNumber: current,
         }
+      }, () => {
+        const totalUnRead = (records || []).reduce((acc, item) => (acc + item.unReadNum), 0)
+        if (!totalUnRead) {
+          // 如果未读为 0, 那么更新 提示组件也为 0
+          
+          const { dispatch } = getStore()
+          dispatch({ type: DECREASE_UNREADNUM })
+        }
       })
     })
   }

src/reducers/user.js

     }
     case DECREASE_UNREADNUM: {
       let { unReadNum } = state
-      unReadNum = unReadNum - action.payload
 
-      if (unReadNum < 0) {
+      if (action.payload === undefined) {
         unReadNum = 0
+      } else {
+        unReadNum = unReadNum - action.payload
+        if (unReadNum < 0) {
+          unReadNum = 0
+        }
       }
 
       return {