如何从app.config获取这个配置值？

我的朋友有以下 app.config。他想要获得的价值address。怎么做？

<configuration>
    <system.serviceModel>
...
           <client>
            <endpoint address="http://ldo:8080/LLService" binding="wsHttpBinding"
                bindingConfiguration="WSHttpBinding_ILLService" contract="LLServiceReference.ILLService"
                name="WSHttpBinding_ILLService">
                <identity>
                    <userPrincipalName value="[email protected] /cdn-cgi/l/email-protection" />
                </identity>
            </endpoint>
        </client>
    </system.serviceModel>
...
</configuration>

尝试这个来获取第一个端点

Configuration configuration =    ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.PerUserRoamingAndLocal);
ServiceModelSectionGroup serviceModelSectionGroup = ServiceModelSectionGroup.GetSectionGroup(configuration);
ClientSection clientSection = serviceModelSectionGroup.Client;
var el = clientSection.Endpoints[0];
return el.Address.ToString();