Question

关于ASP.NET Replace方法未将对象引用到实例 C#

public string detailsms(int details,string xxx)
{
string cmdText = "select * from details where details_id=" + details;
SqlCommand sqlCommand = new SqlCommand(cmdText, sqlConn);
sqlConn.Open();

SqlDataReader dr = sqlCommand.ExecuteReader();
CalculateExpression js = new CalculateExpression();

string mdgd = "";
string mdkd = "";
string mdhd = "";
string xtkd = "";
string open = "";
string dbcz = "";
string mdxz = "";
int shop = 0;
int sum = 0;

while (dr.Read())
{
sum = Convert.ToInt32(dr["details_sum"].ToString());
mdgd = dr["details_mdgd"].ToString();
mdkd = dr["details_mdkd"].ToString();
mdhd = dr["details_mdhd"].ToString();
xtkd = dr["details_xtkd"].ToString();
int mdxzid = Convert.ToInt32(dr["details_heaps"].ToString());
heapsVO heapsvo = new heapsVO(mdxzid);
mdxz = heapsvo.HeapsName.ToString();
int id = Convert.ToInt32(dr["details_open"].ToString());
openVO openvo = new openVO(id);
open = openvo.OpenName;
dealersVO dealersvo = new dealersVO(Convert.ToInt32(dr["details_dealers"].ToString()));
shop = dealersvo.DealersShopid;
floorVO floorvo = new floorVO(Convert.ToInt32(dr["details_floor"].ToString()));
dbcz = floorvo.FloorValue.ToString();
}

string value = string.Empty;
int sl = 0;
string gs = "";

if (open == "平开")
{
formula1DB formula1db = new formula1DB();
formula1VO formula1vo = new formula1VO(formula1db.selectformula(shop));
if(mdxz == "有垛")
{
mdxz = formula1vo.Formula1Yd.ToString();
}
else if(mdxz == "单面无垛")
{
mdxz = formula1vo.Formula1Dmwd.ToString();
}
else if(mdxz == "双面无垛")
{
mdxz = formula1vo.Formula1Smwd.ToString();
}

gs = formula1vo.Formula1Msgd.Replace("x", mdgd).ToString().Replace("y", mdkd).ToString().Replace("z", mdhd).ToString().Replace("i", dbcz).ToString().Replace("b", xtkd).ToString().Replace("a", mdxz).ToString();
value = js.Calculate(gs).ToString() + "*";
value = value + js.Calculate(formula1vo.Formula1Mskd.Replace("x", mdgd).Replace("y", mdkd).Replace("z", mdhd).Replace("i", dbcz).Replace("b", xtkd).Replace("a", mdxz)).ToString();
value = value + "=" + sum.ToString() + "扇";
} return value;
}

Answer 1

从代码来看如果出现Replace方法为将对象引用到实例应该是formula1vo对象初始化出现了问题,或者是Formula1Msgd属性的问题

Answer 2

一般出现这个提示肯定是变量值为null。你可以用断点调试一下

Answer 3

看看你的字符串有没有值