The mobile terminal uses the list component of vantui. When multiple tab items are switched back and forth, the list is loaded many times, resulting in the failure of normal display of data

problem ： stay tab When switching items ：

changTab () {
    
   this.loading = false;
   this.finished = false;
   this.pageNum = 0
   this.list = []
   this.onLoad()
}

Problem phenomenon ： Loaded the list twice

Solution ：

changTab () {
    
   this.loading = true;
   this.finished = false;
   this.pageNum = 0
   this.list = []
   this.onLoad()
}