在app.config中增加appSettings節點後，運行到conn.open時報如下錯誤：
“System.Transactions.Diagnostics.DiagnosticTrace”的類型初始值設定項引發異常。”
將configSections節點放到configuration下的第一元素後問題解決，原因未知。
app.config改動前：
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="busCity"
value="上海,東莞,中山,麗水,樂山,佛山,保定,北海,南京,南充,南寧,南通,台州,合肥,唐山,安陽,宜賓,巴中,常州,常德,廣元,廣
州,德陽,惠州,成都,揚州,攀枝花,昆明,昭通,杭州,汕頭,江門,泰州,瀘州,淮安,深圳,清遠,煙臺,玉林,珠海,蘇州,衢州,達州,遂寧,鄭州,
重慶,鎮江,長沙,陽江,雅安,青島,韶關"/>
<add key="busId"
value="398328,595874,662326,280787,352434,601492,357595,355542,293437,390110,354921,489828,280796,390186,622586,338884,352959,347956,283053,376904,351940,662530,351110,662499,348289,690040,390582,609990,621734,277073,673785,666466,327372,354010,282585,635260,666754,398034,357334,556102,611718,281511,352419,351093,347918,399907,419461,359516,655530,351904,397721,674569"/>
</appSettings>
<configSections>
<sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="TrainTickets.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
</configSections>
</configuration>
app.config改動後：
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="userSettings"
type="System.Configuration.UserSettingsGroup, System, Version=2.0.0.0,
Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="TrainTickets.Properties.Settings"
type="System.Configuration.ClientSettingsSection, System,
Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
</configSections> <appSettings>
<add key="busCity"
value="上海,東莞,中山,麗水,樂山,佛山,保定,北海,南京,南充,南寧,南通,台州,合肥,唐山,安陽,宜賓,巴中,常州,常德,廣元,廣
州,德陽,惠州,成都,揚州,攀枝花,昆明,昭通,杭州,汕頭,江門,泰州,瀘州,淮安,深圳,清遠,煙臺,玉林,珠海,蘇州,衢州,達州,遂寧,鄭州,
重慶,鎮江,長沙,陽江,雅安,青島,韶關"/>
<add key="busId"
value="398328,595874,662326,280787,352434,601492,357595,355542,293437,390110,354921,489828,280796,390186,622586,338884,352959,347956,283053,376904,351940,662530,351110,662499,348289,690040,390582,609990,621734,277073,673785,666466,327372,354010,282585,635260,666754,398034,357334,556102,611718,281511,352419,351093,347918,399907,419461,359516,655530,351904,397721,674569"/>
</appSettings>
</configuration>