ApplicationSetting 节点的内容：
<applicationSettings>
<MyWeb.Properties.Settings>
<setting name="MyWeb_EducationServiceService"
serializeAs="String">
<value>http://172.27.35.10:8080/dataexchangeweb/ws/EducationService</value>
</setting>
<setting name="MyWeb_DataExchangeService_EducationServiceService"
serializeAs="String">
<value>http://10.0.0.11:8080/exchangeserviceweb/ws/EducationService</value>
</setting>
</MyWeb.Properties.Settings>
</applicationSettings>
仔细核对代码，原来在引用web service时, 配置节点configSections, 中的内容也添加了一行：
<configSections>
<sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="MyWeb.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</sectionGroup>
</configSections>