void SearchAll()
 {
     IsBusy = true;
     Task.Run(() =>
     {
         offset   = 0;
         var info = CloudMusicApiHelper.SearchAll(KeyWords, 30, offset);
         if (info != null)
         {
             if (info.code == 200)
             {
                 if (SearchResult == null)
                 {
                     SearchAllResult = info;
                 }
                 offset += 30;
                 IsBusy  = false;
             }
         }
     });
 }