asp.net 处理原文件中过长的viewstate代码_.net

asp.net 处理原文件中过长的viewstate代码

 
public class xvpage : page 
{ 
static private directoryinfo _dir; 
private directoryinfo dir 
{ 
get 
{ 
if (_dir == null) 
{ 
_dir = new directoryinfo(path.combine(appdomain.currentdomain.basedirectory, "app_data")); 
if (!_dir.exists) 
_dir.create(); 
_dir = new directoryinfo(path.combine(_dir.fullname, "viewstate")); 
if (!_dir.exists) 
_dir.create(); 
} 
return _dir; 
} 
} 
protected override object loadpagestatefrompersistencemedium() 
{ 
pagestatepersister ps = this.pagestatepersister; 
ps.load(); 
if (ps.controlstate != null) 
ps.controlstate = antiserialization((string)ps.controlstate); 
if (ps.viewstate != null) 
ps.viewstate = antiserialization((string)ps.viewstate); 
return new pair(ps.controlstate, ps.viewstate); 
} 
protected override void savepagestatetopersistencemedium(object state) 
{ 
pagestatepersister ps = this.pagestatepersister; 
if (state is pair) 
{ 
pair pair = (pair)state; 
ps.controlstate = pair.first; 
ps.viewstate = pair.second; 
} 
else 
{ 
ps.viewstate = state; 
} 
if (ps.controlstate != null) 
ps.controlstate = antiserialization(ps.controlstate); 
if (ps.viewstate != null) 
ps.viewstate = antiserialization(ps.viewstate); 
ps.save(); 
} 
private object antiserialization(string stateid) 
{ 
string statestr = (string)cache[stateid]; 
string file = path.combine(dir.fullname, stateid); 
if (statestr == null) 
statestr = file.readalltext(file); 
else 
cache.remove(stateid); 
return new objectstateformatter().deserialize(statestr); 
} 
private string antiserialization(object obj) 
{ 
string value = new objectstateformatter().serialize(obj); 
string stateid = (datetime.now.ticks + (long)value.gethashcode()).tostring(); //产生离散的id号码 
file.writealltext(path.combine(dir.fullname, stateid), value); 
cache.insert(stateid, value); 
return stateid; 
} 
protected override void onunload(eventargs e) 
{ 
base.onunload(e); 
datetime dt = datetime.now.addminutes(-20); 
foreach (fileinfo fl in dir.getfiles()) 
if (fl.lastaccesstime < dt) 
try 
{ 
fl.delete(); 
} 
catch 
{ 
} 
} 
} 