未将对象引用设置到对象的实例?????????????????
0
悬赏园豆：50
[已关闭问题]
关闭于 2014-07-07 23:58
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<connectionStrings>
<add name="dbConnStr" connectionString="Data Source=.;Initial Catalog=BookManagement;User ID=sa;Password=nash"/>
</connectionStrings>
</configuration>
namespace BookManagementDAL
{
class Sqlhelper
