string url = "http://localhost:52416/Controls/Support_Survey.aspx?GUID=4aa4caca-f5cb-11e2-b582-635fb56c00b9";
string lastPart = url.Split('?').Last().Replace("GUID=",string.Empty);
您的代码是对 SQL 注入的探测,因此请使用SqlCommand.Parameters 属性
SqlCommand command = // your sql command;
database.InsertUpdate(String.Format("CALL spSurveyAnswer_Insert('{0}', '{1}','{2}');", @selectValue1, @txtFeedBack, @PassGUID_HERE));
command.Parameters.AddWithValue("@selectValue1", selectValue1);
command.Parameters.AddWithValue("@txtFeedBack", txtFeedBack.Text);
command.Parameters.AddWithValue("@PassGUID_HERE", lastPart );