AppSettings, 与ConfigurationManager比较, ConfigurationManager 无法取到链接字符串问题

Question

我在类库中取链接字符串,在类库app.config文件中用分别用appsettings和connnectionstring配置了链接字符串
如果用ConfigurationSettings.AppSettings["SQLConnString1"];就能取到值,
但是用ConfigurationManager就取不到,提示"未将对象引用设置到对象的实例"
不解,请指教,我的环境: vs2005 

Answer 1

ConfigurationManager.AppSettings["SQLConnString1"]就能取到值了啊？

Answer 2

System.Configuration.ConfigurationManager.AppSettings["connnectionstring"];

Answer 3

public string strConn = WebConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString;

Answer 4

引用名称空间:using System.Web.Configuration;
配置文件:<connectionStrings>
        <add name="NorthwindConnectionString" connectionString="Data Source=.;Initial Catalog=Northwind;Integrated Security=True"
            providerName="System.Data.SqlClient" />
    </connectionStrings>

Answer 5

问题解决, 不是代码的问题,是我装了resharper的关系, 具体为什么不清楚. 
卸载就好了