private void button2_Click(object sender, EventArgs e)
{
if (Add_City_Is_NumberOrNull())
{
MessageBox.Show("城市名不能为空或者纯数字");
return;
}
if (grp1.Add_City(textBox3.Text.ToString()))
{
MessageBox.Show("数据添加成功");
}
else
{
MessageBox.Show("已存在此城市");
}
}