读取xml中数据库连接字符串

<?xml version="1.0" encoding="utf-8"?>
<!--
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<configuration>
<appSettings></appSettings>
<system.web>
<compilation debug="true" targetFramework="4.5" />
<httpRuntime targetFramework="4.5" />
</system.web>

<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-5.1.0.0" newVersion="5.1.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-1.5.2.14234" newVersion="1.5.2.14234" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Http" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.2.2.0" newVersion="5.2.2.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.2.2.0" newVersion="5.2.2.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<system.webServer>
<handlers>
<remove name="ExtensionlessUrlHandler-Integrated-4.0" />
<remove name="OPTIONSVerbHandler" />
<remove name="TRACEVerbHandler" />
<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
</handlers>
</system.webServer>
<connectionStrings>
<add name="WaiterDeviceDbConnStr" connectionString="data source=192.168.19.79;initial catalog=POS20141202;persist security info=True;user id=datascan;password=DTSbsd7188228" providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration>

1） 以上是webservice项目中的 web.config文件，需要读到数据库连接信息

　　可以直接用 string conStr = ConfigurationManager.ConnectionStrings["sqlString"].ConnectionString;

2）如果是自己新建的xml文件，也可以直接从xml中读取信息

　　XmlDocument xmlDoc = new XmlDocument();
　　xmlDoc.Load("config.xml");
　　XmlNode conNode= xmlDoc.SelectSingleNode("configuration/connectionStrings/add[@name='SqlString']");
　　string conn = conNode.Attributes["connectionString"];