//全域變數：
int FirstCol, FirstRow, LastCol, LastRow;
bool FirstSelect;
 
void __fastcall TForm1::StringGrid1SelectCell(TObject *Sender, int ACol,
      int ARow, bool &CanSelect)
{
   // 記錄點選的第一個點與最二個點
   if(FirstSelect)
   {
      FirstCol = ACol;
      FirstRow = ARow;
      FirstSelect = false;
   }
   else
   {
      FirstSelect = true;
      LastCol = ACol;
      LastRow = ARow;
   }
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
   // 選擇預計算的範圍後，按下計算button得到結果
   int c, r, i, j;
   int TCount, TSum;
   float TAve;
   c = LastCol - FirstCol   1;
   r = LastRow - FirstRow   1;
   TCount = c * r;
   Edit1->Text = TCount;
   for(i = FirstCol; i <= LastCol; i  )
   {
      for(j = FirstRow; j <= LastRow; j  )
         TSum = TSum   StrToInt(StringGrid1->Cells[j][i]);
   }
   Edit2->Text = TSum;
   TAve = TSum / TCount;
   Edit3->Text = TAve;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
   FirstSelect = true;
}