web程序中获取应用程序系统变量的方法（ For.net 1.1)

获取系统变量在.net 的web应用程序中的确是非常方便，比如获取 "http://ap2:8080/"或者"http://10.0.0.1/mypplication/"等诸如此类的系统变量。
注：本文主要是针对.net Framework 1.0、1.1的情况，因为.net 2.0的命名空间已经发生了很大的变化，在后面的文章中将会专门加以介绍。

为描述方便，先新建一aspx文件，前台文件如下：

< body  MS_POSITIONING ="GridLayout" >
         < form  id ="Form2"  method ="post"  runat ="server" >
             < FONT  face ="宋体" >
                 < asp:Button  id ="btn_Page"  style ="Z-INDEX: 101; LEFT: 8px; POSITION: absolute; TOP: 16px"  runat ="server"
                    Text ="通过Page获取" ></ asp:Button >
                 < asp:Label  id ="lbInfo1"  style ="Z-INDEX: 102; LEFT: 48px; POSITION: absolute; TOP: 56px"  runat ="server" ></ asp:Label >
                 < asp:Button  id ="btn_ServerVal"  style ="Z-INDEX: 103; LEFT: 520px; POSITION: absolute; TOP: 16px"
                    runat ="server"  Text ="通过ServerVariables获取" ></ asp:Button >
                 < asp:Label  id ="lbInfo2"  style ="Z-INDEX: 104; LEFT: 48px; POSITION: absolute; TOP: 80px"  runat ="server" ></ asp:Label >
                 < asp:Label  id ="lbInfo3"  style ="Z-INDEX: 105; LEFT: 48px; POSITION: absolute; TOP: 104px"  runat ="server" ></ asp:Label >
                 < asp:Button  id ="btn_Cintext"  style ="Z-INDEX: 106; LEFT: 280px; POSITION: absolute; TOP: 16px"
                    runat ="server"  Text ="通过Context获取" ></ asp:Button ></ FONT >
         </ form >
     </ body >

第一种方法，直接在在页面中获取。利用Page.Request命名空间。

private   void  btn_Page_Click( object  sender, System.EventArgs e)
         ... {
            this.lbInfo2.Text="";
            this.lbInfo3.Text="";
            this.lbInfo1.Text=Page.Request.ApplicationPath+"<br/>"
                +Page.Request.CurrentExecutionFilePath+"<br/>"
                +Page.Request.UserHostAddress+"<br/>"
                +Page.Request.Url.Host+"<br/>"
                +Page.Request.RawUrl+"<br/>"
                +Page.Request.UserHostName+"<br/>"
                +Page.Request.Url.HostNameType+"<br/>"
                +Page.Request.Url.Port+"<br/>"
                +Page.Request.UrlReferrer.Host+"<br/>"
                +Page.Request.Url.LocalPath+"<br/>"
                +Page.Request.Url.Authority+"<br/>"
                +Page.Request.Url.UserInfo+"<br/>"
                +"<br/>";
        
        }

第二种方法：在非Web项目中用Context的Request方法。

private   void  btn_Cintext_Click( object  sender, System.EventArgs e)
         ... {
            this.lbInfo1.Text="";
            this.lbInfo3.Text="";
            this.lbInfo2.Text=
                System.Web.HttpContext.Current.Server.MachineName+"<br/>"
                +System.Web.HttpContext.Current.Request.ApplicationPath+"<br/>"
                +System.Web.HttpContext.Current.Request.CurrentExecutionFilePath+"<br/>"
                +System.Web.HttpContext.Current.Request.RawUrl+"<br/>"
                +System.Web.HttpContext.Current.Request.Url+"<br/>"
                +System.Web.HttpContext.Current.Request.UserHostAddress+"<br/>"
                +System.Web.HttpContext.Current.Request.UserHostName+"<br/>"
                +System.Web.HttpContext.Current.Request.RequestType+"<br/>"
                +System.Web.HttpContext.Current.Request.UrlReferrer.Host+"<br/>"
                +System.Web.HttpContext.Current.Request.UrlReferrer.HostNameType+"<br/>"
                +System.Web.HttpContext.Current.Request.Path+"<br/>"
                +System.Web.HttpContext.Current.Request.Url.Port+"<br/>"
                +System.Web.HttpContext.Current.Request.Url.IsDefaultPort.ToString()+"<br/>"
                +System.Web.HttpContext.Current.Request.Url.IsFile.ToString()+"<br/>"
                +System.Web.HttpContext.Current.Request.Url.LocalPath+"<br/>"
                +"<br/>";
        
        }

第三种方法：可以从Request.ServerVariables的集合中获取 。获取的变量也最全。

private   void  btn_ServerVal_Click( object  sender, System.EventArgs e)
         ... {
        
            this.lbInfo1.Text="";
            this.lbInfo2.Text="";
            int loop1, loop2;
            System.Collections.Specialized.NameValueCollection coll;

            //以下两种方式均可
            //coll=Page.Request.ServerVariables; 
            coll=System.Web.HttpContext.Current.Request.ServerVariables; 
            this.lbInfo3.Text="";
            // Get names of all keys into a string array. 
            String[] arr1 = coll.AllKeys; 
            for (loop1 = 0; loop1 < arr1.Length; loop1++) 
            ...{
                this.lbInfo3.Text+=("Key: " + arr1[loop1] + "<br>");
                String[] arr2=coll.GetValues(arr1[loop1]);
                for (loop2 = 0; loop2 < arr2.Length; loop2++) 
                ...{
                    this.lbInfo3.Text+=("Value " + loop2 + ": " + Server.HtmlEncode(arr2[loop2]) + "<br>");
                }
            }
        }

亦可用于 Web service

注意，以上方法获取IP未必真实。