Windows服務ServicesDependedOn的奇怪問題？

Windows服務ServicesDependedOn的奇怪問題？？？

代碼如下

public partial class WinServicePWServiceInstaller : Installer

    {

 

        private ServiceProcessInstaller process;

        private ServiceInstaller service;

        private const string m_SERVICENAME = "myService";

 

        public WinServicePWServiceInstaller()

        {

 

            InitializeComponent();

 

            process = new ServiceProcessInstaller();

            process.Account = ServiceAccount.LocalSystem;

 

          

            service = new ServiceInstaller();

            service.ServiceName =m_SERVICENAME;

            service.StartType = ServiceStartMode.Automatic;

            service.ServicesDependedOn = GetDepengOnServices();

 

            Installers.Add(process);

            Installers.Add(service);

 

        }

        /// <summary>

        ///擷取設定檔的依賴服務

        /// </summary>

        /// <returns></returns>

        private string[] GetDepengOnServices()

        {

            string[] services=null;                              

            string allService = ConfigurationManager.AppSettings["DependOnService"];

            services = new string[] { allService };

            //return services;

            if (allService.IndexOf(';') != -1)

            {

               services = allService.Split(';');

            }

            else

           {

               services =new string[]{ allService};

           }

           return services;

 

        }

    }               

按以上方法寫的 GetDepengOnServices()，在安裝過程中報錯。

改成一下方法不會報錯

/// <summary>

        ///擷取設定檔的依賴服務

        /// </summary>

        /// <returns></returns>

      private string[] GetDepengOnServices()

        {

            string[] services=null;                              

            string allService = ConfigurationManager.AppSettings["DependOnService"];

            services = new string[] { allService };

            return services;

            //if (allService.IndexOf(';') != -1)

            //{

            //    services = allService.Split(';');

            //}

            //else

            //{

            //    services =new string[]{ allService};

            //}

            //return services;

 

        }                  

所讀的配置節 <!--本服務依賴的服務列表-->

    <add key ="DependOnService" value ="MSSQLSERVER"/>

跟蹤後，兩種寫法都能得出正確的結果，為什麼 第一種寫法在安裝過程中會報錯？？？？