从网址获取最后一个值

大家好，
即时通讯从url
检索最后一个值 例如:
const string str ="http://www.codeproject.com/Questions/ask.aspx"
这是恒定的
我的应用程序自动将所有字符串或数字添加为
http://www.codeproject.com/Questions/ask.aspx sadfsf_sdf
http://www.codeproject.com/Questions/ask.aspx skdfwer234
现在我想从url中获取值，添加的新值是什么
结果是= sadfst_sdf
result2是= skdfwer234
像这样

不知道如果有人帮助我，我该怎么办
非常适合
谢谢你.

Hi all,
im retrieve last value from url
example:
const string str="http://www.codeproject.com/Questions/ask.aspx"
this is constant
im my application automaticall added string or number like
http://www.codeproject.com/Questions/ask.aspxsadfsf_sdf
http://www.codeproject.com/Questions/ask.aspxskdfwer234
Now i want to get the value from url what is the new value added
result is=sadfst_sdf
result2 is=skdfwer234
like this

don''t know how can i get like that if any one help me out
greatly appriciate
Thank U.