C#中Strings VS. StringBuilder

string mappingHandler = String.Format(@"""[name='BTSHTTPReceiveModule',path='BTSHTTPReceive.dll',verb='*',scriptProcessor='%programfiles(x86)%Microsoft BizTalk Server 2009HttpReceive64BTSHTTPReceive.dll',resourceType='Unspecified',modules='IsapiModule',requireAccess='Execute']""");
StringBuilder sb = new StringBuilder();
sb.AppendFormat(@"%SystemRoot%system32inetsrvappcmd.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