Private Sub DemoFind()
    Dim currentFind As Excel.Range = Nothing
    Dim firstFind As Excel.Range = Nothing
    Dim Fruits As Excel.Range = Me.Application.Range("A1", "B2")


    ' You should specify all these parameters every time you call this method, 
    ' since they can be overridden in the user interface.
    currentFind = Fruits.Find("apples", , _
        Excel.XlFindLookIn.xlValues, Excel.XlLookAt.xlPart, _
        Excel.XlSearchOrder.xlByRows, Excel.XlSearchDirection.xlNext, False)

    While Not currentFind Is Nothing

        ' Keep track of the first range you find.
        If firstFind Is Nothing Then
            firstFind = currentFind

        ' If you didn't move to a new range, you are done.
        ElseIf currentFind.Address = firstFind.Address Then
            Exit While
        End If

        With currentFind.Font
            .Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red)
            .Bold = True
        End With

        currentFind = Fruits.FindNext(currentFind)
    End While
End Sub

private void DemoFind() 
{
    Excel.Range currentFind = null; 
    Excel.Range firstFind = null;
    Excel.Range Fruits = Application.get_Range("A1", "B3");


    // You should specify all these parameters every time you call this method,
    // since they can be overridden in the user interface. 
    currentFind = Fruits.Find("apples", missing,
        Excel.XlFindLookIn.xlValues, Excel.XlLookAt.xlPart, 
        Excel.XlSearchOrder.xlByRows, Excel.XlSearchDirection.xlNext, false,
        missing, missing); 

    while(currentFind != null) 
    { 
        // Keep track of the first range you find. 
        if (firstFind == null)
        {
            firstFind = currentFind; 
        }

        // If you didn't move to a new range, you are done.
        else if (currentFind.get_Address(missing, missing, Excel.XlReferenceStyle.xlA1, missing, missing)
              == firstFind.get_Address(missing, missing, Excel.XlReferenceStyle.xlA1, missing, missing))
        {
            break;
        }

        currentFind.Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
        currentFind.Font.Bold = true; 

        currentFind = Fruits.FindNext(currentFind); 
    }
}