Winform 利用 Oracle.ManagedDataAccess访问Oracle数据库

Winform 利用 Oracle.ManagedDataAccess访问Oracle数据库时出现以下错误：

Message = "每个配置文件中只允许存在一个 <configSections> 元素，并且，如果存在该元素，它还必须是根 <configuration> 元素的第一个子元素。

出现以上错误时，需调整app.config中配置节点，将configSections的节点放在第一个子元素，入一下配置文件

<?xml version="1.0" encoding="utf-8"?>
<configuration>
	  <configSections>
		<section name="oracle.manageddataaccess.client"
		  type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.122.18.3, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
		<section name="log4net" type="System.Configuration.IgnoreSectionHandler"/>
	  </configSections>
	<startup>
		<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
	</startup>
  <log4net>
    <root>
      <appender-ref ref="LogFileAppender"/>
    </root>
    <appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="./log/log4netfile.txt"/>
      <appendToFile value="true"/>
      <rollingStyle value="Date"/>
      <LockingModel type="log4net.Appender.FileAppender+MinimalLock, log4net"/>
      <datePattern value="yyyyMMdd-HH:mm:ss"/>
      <layout type="log4net.Layout.PatternLayout">
        <param name="ConversionPattern" value="%d [%t] %-5p %c [%x] %X{auth} - Line:%L %m%n"/>
      </layout>
    </appender>
  </log4net>
  <system.data>
    <DbProviderFactories>
      <remove invariant="Oracle.ManagedDataAccess.Client"/>
      <add name="ODP.NET, Managed Driver" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET, Managed Driver"
        type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.122.18.3, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
    </DbProviderFactories>
  </system.data>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <publisherPolicy apply="no"/>
        <assemblyIdentity name="Oracle.ManagedDataAccess" publicKeyToken="89b483f429c47342" culture="neutral"/>
        <bindingRedirect oldVersion="4.122.0.0 - 4.65535.65535.65535" newVersion="4.122.18.3"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <oracle.manageddataaccess.client>
    <version number="*">
      <dataSources>
        <dataSource alias="SampleDataSource" descriptor="(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=ORCL))) "/>
      </dataSources>
    </version>
  </oracle.manageddataaccess.client>
</configuration>