TListView有关问题

TListView问题
以为自己对这个控件有所了解了，今儿个随意测试了个玩意，居然出了问题，百思不得其解，汗颜之，特发出来请大家给与指点。
程序思路如下，表格共有10列，放个定时器每秒钟横向填入一个数字，直至该行填完，然后再增加一行，如此循环：

C/C++ code

void TfrmTest::tmr1Timer(TObject *Sender){  int Row = lv->Items->Count-1;  TListItem* Item = lv->Items->operator [](Row);  if( NULL == Item  ) {       Item = lv->Items->Add(); Item->Caption = "0";   }   else {    int nCount = Item->SubItems->Count;    if( nCount >= 10 ) {       Item = lv->Items->Add(); Item->Caption = "0";    }   }   Item->SubItems->Add("1");//问题产生的行, ERROR:List Index out of bounds.}

C/C++ code

void __fastcall TForm1::Timer1Timer(TObject *Sender){    static int i = 0;    TListItem *li;    if (lv->Items->Count > 0)    {        li = lv->Items->Item[lv->Items->Count - 1];    }    else    {        li = lv->Items->Add();        li->Caption = i++;        return;    }    if (li->SubItems->Count >= 9)    {        li = lv->Items->Add();        li->Caption = i++;    }    else        li->SubItems->Add(i++);}