任何人都可以知道吗?
输入的字符串是不正确的格式吗?为什么
public float getshipping(string deliveryarea)
{
SqlCommand cmd3 = new SqlCommand("select shipping from delivery where status='A' and area='" + deliveryarea + "'", con);
SqlDataReader dr3 = cmd3.ExecuteReader();
while (dr3.Read())
{
shiping = float.Parse(dr3[0].ToString());//error
}
dr3.Close();
return shiping;
}