Asp.net 基于Cookie简易的权限判断

写入cookie页面，创建cookie后，设置cookie属性，并添加到response.cookies中读取cookie，利用cookie的名字或索引从request.cookies中取得改写cookie，先创建一个同名的cookie，读取request中同名的cookie,把读取cookie的属性值付给新的对象，加入到response.cookies中创建一个basepage页面，其他的页面继承自这个页面，把权限判断的代码有单个页面的page_load转移到basepage的preload中，下面是basepage的主要代码

public class basepage : system.web.ui.page
{
private string pagename;
public basepage()
{
this.page.preload += page_load;
}
protected void page_load(object sender, eventargs e)
{
if (!ispostback)
{
uri r = this.request.url;
pagename = r.absolutepath;
if (needtocheck())
{
if (!hasauthentication())
{
httpcontext.current.response.redirect("noauthenticationpage.aspx");
}
}
}
}
private bool needtocheck()
{
if (pagename.contains("noauthenticationpage.aspx") || pagename == "login.aspx" )
{
return false;
}
return true;
}
private bool hasauthentication()
{
//look into the config file or database,to see whether this page is in the allow accessing list of the role or not;
//the signature of the function is like this
//queryinconfig(m_userrole,pagename);
if (pagename.contains("default3.aspx") && userrole == "2")
{
return false;
}
return true;
}
protected httpcookie _requestcookie;
protected httpcookie _responsecookie;
private bool b_isnewcookie = true;
public string userrole
{
get
{
return getcookievalue("userrole");
}
set
{
setcookievalue("userrole", value);
}
}
public string username
{
get
{
return getcookievalue("username");
}
set
{
setcookievalue("username", value);
}
}
protected void setcookievalue(string name, string value)
{
setresponsecookie();
_responsecookie[name] = value;
}
private string getcookievalue(string name)
{
setreqeustcookie();
if (_requestcookie != null)
{
return _requestcookie[name];
}
return null;
}
protected void setreqeustcookie()
{
_requestcookie = httpcontext.current.request.cookies["cookie_name"];
}
protected void setresponsecookie()
{
if (b_isnewcookie)
{
httpcontext.current.response.cookies.remove("cookie_name");
_responsecookie = new httpcookie("cookie_name");
datetime dtnow = datetime.now;
timespan tsminute = new timespan(0, 2, 0, 0);
_responsecookie.expires = dtnow + tsminute;
_responsecookie["userrole"] = userrole;
_responsecookie["username"] = username;
httpcontext.current.response.cookies.add(_responsecookie);
b_isnewcookie = false;
}
}
}