Question

SqlConnection conn = new SqlConnection(sqlcon);不支持关键字: “.\sqlexpress;attachdbfilename” 怎么

Answer 1

using System.Data.SqlClient;
添加了吗？
sqlcon，连接字符串写正确了吗？

Answer 2

要么@"data source=.\sqlexpress
要么data source=.\\sqlexpress

Answer 3

string sqlcon = @"data source=.\sqlexpress;initial catalog=DBName;persist security info=True;user id=datauser;password=1";
SqlConnection conn = new SqlConnection(sqlcon);