C#中Strings VS. StringBuilder

 string mappingHandler = String.Format(@"""[name='BTSHTTPReceiveModule',path='BTSHTTPReceive.dll',verb='*',scriptProcessor='%programfiles(x86)%\Microsoft BizTalk Server 2009\HttpReceive64\BTSHTTPReceive.dll',resourceType='Unspecified',modules='IsapiModule',requireAccess='Execute']""");
 StringBuilder sb = new StringBuilder();
 sb.AppendFormat(@"%SystemRoot%\system32\inetsrv\appcmd.exe set config {0} /section:handlers /+", "\"AppWeekSite/AppWeek\"");
 sb.Append(mappingHandler);
 sb.AppendFormat(@" > {0}\AppCmdOutE2EDeploy.txt", ContextBag.TestDir);
 Trace.WriteLine(sb.ToString(), TestCaseLogCategory.Info);
 Exec.ExecuteCommand(sb.ToString());

String Class (System) | Microsoft Docs

https://docs.microsoft.com/en-us/dotnet/api/system.string?view=netframework-4.7.1

Strings @MSDN

http://msdn.microsoft.com/en-us/library/ms228362.aspx

StringBuilder Class @MSDN

http://msdn.microsoft.com/en-us/library/system.text.stringbuilder.aspx

Using the StringBuilder Class @MSDN

http://msdn.microsoft.com/en-us/library/2839d5h5(v=vs.71).aspx

String Vs StringBuilder (C#) @CodeProject

http://www.codeproject.com/KB/string/string.aspx