电子邮件的判断

procedure TForm1.Edit1Exit(Sender: TObject);
var
  StrCount, FindStrCount: Integer;
begin
  FindStrCount := 0;
  For StrCount := 1 to Length(Edit1.Text) do
  begin
    If MidStr(Edit1.Text, StrCount, 1) = '@' then
       FindStrCount := FindStrCount + 1;
  End;
  if FindStrCount <> 1 then
  begin
    MessageBox(0,'请正确输入电子邮箱！','注意',MB_OK+MB_ICONWARNING);
    Edit1.Text.Clear;
    Edit1.Text.SetFocus;
   end;
end;