听起来像数据问题，这些解决问题会停止错误，但可能会污染结果。你需要找出Allbarcodes中出错的地方[i]



1.使用TryParse，如果失败替换为0

Sound like a data issue, these work around will stop the error but it might pollute the results. You need to find out what when wrong in Allbarcodes[i]

1. Use TryParse, if failed substitute with 0

long sumOfnum = 0;
Int64.TryParse(Allbarcodes[i], out sumOfnum);
barcodeList.Add(sumOfnum);

2.在转换前检查Allbarcodes [i]是否为空

2.check if Allbarcodes[i] is empty before converting

if (!string.IsNullOrEmpty(Allbarcodes[i]) )
{
    long sumOfnum = Summation(Convert.ToInt64(Allbarcodes[i]));
    barcodeList.Add(sumOfnum);
}