将VendorCreditApply添加到VendorCreditApplyList Suitetalk

我不知道为什么在尝试用VendorCreditApplyList 更新VendorCredit时会出现此错误

var creditObj = new List<VendorCredit>(searchResultCredit.recordList.Cast<VendorCredit>()).FirstOrDefault();
VendorCreditApplyList vCreditApplyList = new VendorCreditApplyList();
VendorCreditApply[] vCreditApplyArray = new VendorCreditApply[creditObj.applyList.apply.Length + 1];
var searchResultBill = _service.search(transactionsSearchBill);
if (searchResultCredit.status.isSuccess)
{
   var billObj = new List<VendorBill>(searchResultBill.recordList.Cast<VendorBill>()).FirstOrDefault();
   for(int i = 0; i < creditObj.applyList.apply.Length; i ++)
   {
      vCreditApplyArray[i] = creditObj.applyList.apply[i];
   }
   vCreditApplyArray[creditObj.applyList.apply.Length] = new VendorCreditApply()
      {
         amount = (double)creditAmount,
         amountSpecified = true,
         apply = true,
         applySpecified = true,
         applyDate = DateTime.Now,
         applyDateSpecified = true,
         currency = billObj.currencyName,
         doc = Convert.ToInt64(billObj.internalId),
         docSpecified = true,
         due = billObj.userTotal,
         dueSpecified = true,
         line = 0,
         lineSpecified = true,
         refNum = null,
         total = billObj.userTotal,
         totalSpecified = true,
         type = "Bill"
      };
}
vCreditApplyList.apply = vCreditApplyArray;
creditObj.applyList = vCreditApplyList;              
WriteResponse writeRes = _service.update(creditObj);
return writeRes.status;

我得到错误：

"请求全部替换时，必须指定子列表applyList的所有行"

我真的不明白。。。