输入的字符串格式不正确?怎么解决 [英] input string was not in correct format? how to solve

问题描述

有人可以知道吗，是我.......

错误代码:

Can Anyone know this, ans me.......

Error code:

public float getshipping(string deliveryarea)
{
    SqlCommand cmd3 = new SqlCommand("select shipping from delivery where status='A' and area='" + deliveryarea + "'", con);
    SqlDataReader dr3;
    dr3 = cmd3.ExecuteReader();
    while (dr3.Read())
    {
        shipping = float.Parse(dr3[0].ToString());
    }
    dr3.Close();
    return shipping;
}

推荐答案

您正尝试将值转换为float.检查在dr3 [0]中获得的值.

You are trying to convert a value to float..Check what value you are getting in dr3[0].

您正试图解析float中可能是数字的值.
pl.检查 dr3 [0] .ToString()

You are trying to parse the value in float that might bot be digits.
pl. check the value of dr3[0].ToString()

public float getshipping(string deliveryarea)
  {
      float shipping =0;
      SqlCommand cmd3 = new SqlCommand("select shipping from delivery where status='A' and area='" + deliveryarea + "'", con);
      SqlDataReader dr3;
      dr3 = cmd3.ExecuteReader();
      while (dr3.Read())
      {
          float.TryParse(Convert.ToString(dr3[0]),out shipping);
      }
      dr3.Close();
      return shipping;
  }

您可以使用float.TryParse代替float.Parse，如果有无效值，它将返回0.

Instead of float.Parse you can use float.TryParse which will return 0 if there is invalid value.

这篇关于输入的字符串格式不正确?怎么解决的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！