修改网络教室部分问题

classRoom/src/main/java/com/dayayuemeng/classroom/ui/TeacherNetClassRoomActivity.java

@@ -1041,6 +1041,7 @@ public class TeacherNetClassRoomActivity extends BaseMVPActivity<AcNetClassRoomT
                 transaction.show(whiteBoardFragment);
                 classViewModel.switchDisplay(getRoomId(), ScreenDisplay.Display.WHITEBOARD
                         , userInfo.getUserId(), false);
+                classViewModel.getBarrageMessageEvent().postValue(false);
             } else {
                 transaction.hide(whiteBoardFragment);
             }