private void b_buy_Click(object sender, EventArgs e)
{
if (Convert.ToInt32(b_nu) < Convert.ToInt32(buy_book_num)) //库存量不够，无法购买
{
MessageBox.Show("当前库存不足");
}
else
{
if (Convert.ToDouble(price) < Convert.ToDouble(un) * Convert.ToInt32(b_nu))//获取余额,金额不足充值
{
MessageBox.Show("您的余额不足，无法购买，请先充值");
}
else
{
MessageBox.Show("购买成功");//提示购买成功,(做三件事)在My_account里显示购买记录，在Login_in里修改库存，在My_account里修改我的余额
My_accont f = new My_accont();
f.history_of_buy = t_1.Text;
Login_in f1 = new Login_in();
}
}
}
private void tool_7_Click(object sender, EventArgs e)
{
My_accont f7 = new My_accont();
f7.ShowDialog();
}
