先在App.config中配置一个连接
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
</startup>
<connectionStrings>
<add name="strCon" connectionString="server=DUANXINGYUN\SQLEXPRESS;user id=sa; password=1120061929; database=test1;"/>
</connectionStrings>
</configuration>
然后获取连接字符串:
public string _connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["strCon"].ToString();
SqlConnection conn = new SqlConnection(_connectionString);
conn.Open();
注意:这里需要引入using System.Configuration;