«

I have a question concerning Viewstate and how it relates
to a Control's event handler (if at all). I did not think
there was any association between a Control's viewstate
and an event handler until I attempted to clear Viewstate
from the Page.

Here is the problem I am facing: in our system, we do not
want to use Viewstate at all. We have a framework in which
all controls are dynamically created for a page (for
better or for worse).

However, when we set EnableViewState to false (at any
level), there remains some Viewstate generated for the
page. Things get worse when we dynamically generate
CheckBox controls and add them as child controls to a
DataGrid-the Viewstate size becomes very large.

I implemented overrides for
LoadPageStateFromPersistenceMedium and
SavePageStateToPersistenceMedium methods for our base Page
class. Essentially, for Load... I return null and for
Save... I do nothing. This works great since Viewstate on
the client now contains 0 bytes in all cases. There is
only one problem-the event handlers for the click events
on all of our ImageButtons do not work now. How could this
be? Is there some association between a server control's
event handler and it's Viewstate? or is this a bug? If so,
what could be a workaround?

if you don't use ViewState , don't use <Form runat=server> too.
if you want postback,ViewState is very important.
some controls (i.e. DataGrid) use ViewState to store items count,
if ViewState disabled , DataGrid will display nothing when postback.

maybe these code can help you:

namespace Web
{
using System;
using System.Collections;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.IO;
using System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Xml;

using System.Threading;
using System.Diagnostics;

public class LightStatePage : System.Web.UI.Page
{

#region HashCodeLock
private class HashCodeLockTimeoutException:Exception
{
public HashCodeLockTimeoutException(string msg):base(msg){}
}

/// <remarks>
/// <code>
/// using(new LostinetSample.HashCodeLock(111))
/// {
/// //now this thread is synchronized for int 111
/// }
/// </code>
/// </remarks>
private sealed class HashCodeLock:IDisposable
{
class Allocator
{
class Node
{
int typecode;
int hashcode;
public Node(object obj)
{
typecode=obj.GetType().GetHashCode();
hashcode=obj.GetHashCode();
}
override public bool Equals(object obj)
{
if(obj == null)
return false;
if(obj is Node)
{
Node n=(Node)obj;
return n.typecode==typecode&&n.hashcode==hashcode;
}
return false;
}
override public int GetHashCode()
{
return typecode+hashcode;
}
}

static ArrayList al=new ArrayList();
static public object Alloc(object obj)
{
object n=new Node(obj);
lock(al.SyncRoot)
{
int index=al.IndexOf(n);
if(index!=-1)
{
n=al[index];
}
al.Add(n);
return n;
}
}
static public object Release(object obj)
{
object n=new Node(obj);
lock(al.SyncRoot)
{
int index=al.IndexOf(n);
if(index==-1)
throw(new Exception("cant release obj:node not found"));
n=al[index];
al.RemoveAt(index);
return n;
}
}
}


public HashCodeLock(object obj):this(obj,Timeout.Infinite)
{
}
public HashCodeLock(object obj,TimeSpan
tsTimeout):this(obj,(int)tsTimeout.TotalMillisecon ds)
{
}
public HashCodeLock(object obj,int msTimeout)
{
if(obj==null)throw(new ArgumentNullException("obj"));

SetM();

if(!Monitor.TryEnter(Allocator.Alloc(obj),msTimeou t))
{
Allocator.Release(obj);
throw(new HashCodeLockTimeoutException("lock timeout"));
}
o=obj;
released=false;
}

[Conditional("DEBUG")]
void SetM()
{
StackTrace st=new StackTrace();
for(int i=0;i<st.FrameCount;i++)
{
MethodBase mb=st.GetFrame(i).GetMethod();
if(mb.ReflectedType!=typeof(HashCodeLock))
{
m=mb.ReflectedType.FullName+":"+mb.ToString();
break;
}
}
}

bool released=true;
object o;
string m=" unknown method (not query in release) ";

void IDisposable.Dispose()
{
if(released)
throw(new Exception("lock at "+m+" already released!"));
released=true;
Monitor.Exit(Allocator.Release(o));
}
~HashCodeLock()
{
if(!released)
throw(new Exception("lock at "+m+" have not released!"));
}
}
#endregion

protected LightStatePage()
{
}

protected virtual bool EnableDiskViewState
{
get
{
return true;
}
}

protected override object LoadPageStateFromPersistenceMedium()
{
if(EnableDiskViewState)
{
DateTime time=new
DateTime(long.Parse((string)base.LoadPageStateFrom PersistenceMedium()));;

LosFormatter lf=new LosFormatter();
using(new HashCodeLock(time))
{
using(Stream s=LoadPagePersistenceStream(time))
{
return lf.Deserialize(s);
}
}
}
else
{
return base.LoadPageStateFromPersistenceMedium();
}
}
protected override void SavePageStateToPersistenceMedium(object
viewLightPageState)
{
if(EnableDiskViewState)
{
LosFormatter lf=new LosFormatter();
using(new HashCodeLock(_time))
{
using(Stream s=SavePagePersistanceStream(_time))
{
lf.Serialize(s,viewLightPageState);
}
}

base.SavePageStateToPersistenceMedium(_time.Ticks. ToString());
}
else
{
base.SavePageStateToPersistenceMedium(viewLightPag eState);
}
}

static string GetSiteName(HttpContext context)
{
string applmdpath;

try
{
applmdpath=context.Request.ServerVariables["APPL_MD_PATH"];
}
catch
{
HttpWorkerRequest wr=(HttpWorkerRequest)
typeof(HttpContext).InvokeMember("get_WorkerReques t"

,BindingFlags.InvokeMethod|BindingFlags.Instance|B indingFlags.Public|Binding
Flags.NonPublic
,null,context,new object[]{}
);
applmdpath=wr.GetServerVariable("APPL_MD_PATH");
}
applmdpath=applmdpath.Replace("/","_");
return applmdpath;
}

#region ?????
override protected void OnInit(EventArgs e)
{
//??Request.ServerVariables?????
GetSiteName(Context);

if(new Random(Guid.NewGuid().GetHashCode()).Next(1000)==1 )
{
ClearCacheHandler handler=new ClearCacheHandler(ClearCacheAsync);
handler.BeginInvoke(Context,null,null);
}

base.OnInit(e);
}

delegate void ClearCacheHandler(HttpContext context);
static void ClearCacheAsync(HttpContext context)
{
string sitename=GetSiteName(context);
string rootdir=Path.GetTempPath()+"LightStatePageTemp\\"+ sitename+"\\";
if(!Directory.Exists(rootdir))
return;
using(new HashCodeLock("ClearCacheHandler:"+sitename))
{
string str1=rootdir+DateTime.Now.ToString("yyyy-MM-dd HH");
string str2=rootdir+DateTime.Now.AddHours(-1).ToString("yyyy-MM-dd HH");

foreach(string dir in Directory.GetDirectories(rootdir))
{
if(dir==str1||dir==str2)
continue;
try
{
DeleteDirectory(dir);
}
catch(Exception x)
{
try
{
using(FileStream fs=new
FileStream(Path.Combine(context.Request.PhysicalAp plicationPath,"LightStateP
age_ErrorLog.txt"),FileMode.Append))
{
using(StreamWriter sw=new StreamWriter(fs))
{
sw.Write(sitename+"???,????"+dir+"??????"+x.ToStri ng());
sw.Write("\r\n\r\n\r\n");
}
}
}
catch
{
}
}
}
}
}
static void DeleteDirectory(string dir)
{
foreach(string subdir in Directory.GetDirectories(dir))
{
DeleteDirectory(subdir);
}
foreach(string file in Directory.GetFiles(dir))
{
File.Delete(file);
}
Directory.Delete(dir);
}
#endregion

private DateTime _time=DateTime.Now;

protected virtual string GetPegePersistenceFileName(DateTime time)
{
return Path.GetTempPath()
+"LightStatePageTemp\\"
+GetSiteName(Context)+"\\"
+time.ToString("yyyy-MM-dd HH")+"\\"
+Session.SessionID+"\\"
+Request.FilePath+"\\"
+time.Ticks.ToString()
+".txt";
}

protected virtual Stream LoadPagePersistenceStream(DateTime time)
{
string filePath=GetPegePersistenceFileName(time);
return new FileStream(filePath,FileMode.Open,FileAccess.Read) ;
}
protected virtual Stream SavePagePersistanceStream(DateTime time)
{
string filePath=GetPegePersistenceFileName(time);
try
{
return new FileStream(filePath,FileMode.Create);
}
catch
{
string
str=filePath.Substring(0,Math.Max(filePath.LastInd exOf("\\"),filePath.LastIn
dexOf("/")));
CreateDirecotry(str);
return new FileStream(filePath,FileMode.Create);
}
}
protected void CreateDirecotry(string dir)
{
if(dir==null)
throw(new ArgumentNullException("null"));
if(dir.Length==0)
throw(new Exception("???dir"));
try
{
Directory.CreateDirectory(dir);
}
catch
{
string
str=dir.Substring(0,Math.Max(dir.LastIndexOf("\\") ,dir.LastIndexOf("/")));
if(str==dir)
throw(new Exception("????DIR:"+dir));
CreateDirecotry(str);
}
}
}
}

"Frank" <> ????
news:018f01c3b9da$79c7eb60$...
> I have a question concerning Viewstate and how it relates
> to a Control's event handler (if at all). I did not think
> there was any association between a Control's viewstate
> and an event handler until I attempted to clear Viewstate
> from the Page.
>
> Here is the problem I am facing: in our system, we do not
> want to use Viewstate at all. We have a framework in which
> all controls are dynamically created for a page (for
> better or for worse).
>
> However, when we set EnableViewState to false (at any
> level), there remains some Viewstate generated for the
> page. Things get worse when we dynamically generate
> CheckBox controls and add them as child controls to a
> DataGrid-the Viewstate size becomes very large.
>
> I implemented overrides for
> LoadPageStateFromPersistenceMedium and
> SavePageStateToPersistenceMedium methods for our base Page
> class. Essentially, for Load... I return null and for
> Save... I do nothing. This works great since Viewstate on
> the client now contains 0 bytes in all cases. There is
> only one problem-the event handlers for the click events
> on all of our ImageButtons do not work now. How could this
> be? Is there some association between a server control's
> event handler and it's Viewstate? or is this a bug? If so,
> what could be a workaround?
>

So if I don't use Viewstate, I cannot use server-side
event processing either, correct?


>-----Original Message-----
>if you don't use ViewState , don't use <Form
runat=server> too.
>if you want postback,ViewState is very important.
>some controls (i.e. DataGrid) use ViewState to store
items count,
>if ViewState disabled , DataGrid will display nothing
when postback.
>
>maybe these code can help you:
>
>namespace Web
>{
> using System;
> using System.Collections;
> using System.Data;
> using System.Data.SqlClient;
> using System.Drawing;
> using System.IO;
> using System.Reflection;
> using System.Text;
> using System.Text.RegularExpressions;
> using System.Web;
> using System.Web.UI;
> using System.Web.UI.WebControls;
> using System.Xml;
>
> using System.Threading;
> using System.Diagnostics;
>
> public class LightStatePage : System.Web.UI.Page
> {
>
> #region HashCodeLock
> private class HashCodeLockTimeoutException:Exception
> {
> public HashCodeLockTimeoutException(string msg):base
(msg){}
> }
>
> /// <remarks>
> /// <code>
> /// using(new LostinetSample.HashCodeLock(111))
> /// {
> /// //now this thread is synchronized for int 111
> /// }
> /// </code>
> /// </remarks>
> private sealed class HashCodeLock:IDisposable
> {
> class Allocator
> {
> class Node
> {
> int typecode;
> int hashcode;
> public Node(object obj)
> {
> typecode=obj.GetType().GetHashCode();
> hashcode=obj.GetHashCode();
> }
> override public bool Equals(object obj)
> {
> if(obj == null)
> return false;
> if(obj is Node)
> {
> Node n=(Node)obj;
> return n.typecode==typecode&&n.hashcode==hashcode;
> }
> return false;
> }
> override public int GetHashCode()
> {
> return typecode+hashcode;
> }
> }
>
> static ArrayList al=new ArrayList();
> static public object Alloc(object obj)
> {
> object n=new Node(obj);
> lock(al.SyncRoot)
> {
> int index=al.IndexOf(n);
> if(index!=-1)
> {
> n=al[index];
> }
> al.Add(n);
> return n;
> }
> }
> static public object Release(object obj)
> {
> object n=new Node(obj);
> lock(al.SyncRoot)
> {
> int index=al.IndexOf(n);
> if(index==-1)
> throw(new Exception("cant release obj:node not
found"));
> n=al[index];
> al.RemoveAt(index);
> return n;
> }
> }
> }
>
>
> public HashCodeLock(object obj):this
(obj,Timeout.Infinite)
> {
> }
> public HashCodeLock(object obj,TimeSpan
>tsTimeout):this(obj,(int)tsTimeout.TotalMilliseco nds)
> {
> }
> public HashCodeLock(object obj,int msTimeout)
> {
> if(obj==null)throw(new ArgumentNullException("obj"));
>
> SetM();
>
> if(!Monitor.TryEnter(Allocator.Alloc(obj),msTimeou t))
> {
> Allocator.Release(obj);
> throw(new HashCodeLockTimeoutException("lock
timeout"));
> }
> o=obj;
> released=false;
> }
>
> [Conditional("DEBUG")]
> void SetM()
> {
> StackTrace st=new StackTrace();
> for(int i=0;i<st.FrameCount;i++)
> {
> MethodBase mb=st.GetFrame(i).GetMethod();
> if(mb.ReflectedType!=typeof(HashCodeLock))
> {
> m=mb.ReflectedType.FullName+":"+mb.ToString();
> break;
> }
> }
> }
>
> bool released=true;
> object o;
> string m=" unknown method (not query in release) ";
>
> void IDisposable.Dispose()
> {
> if(released)
> throw(new Exception("lock at "+m+" already
released!"));
> released=true;
> Monitor.Exit(Allocator.Release(o));
> }
> ~HashCodeLock()
> {
> if(!released)
> throw(new Exception("lock at "+m+" have not
released!"));
> }
> }
> #endregion
>
> protected LightStatePage()
> {
> }
>
> protected virtual bool EnableDiskViewState
> {
> get
> {
> return true;
> }
> }
>
> protected override object
LoadPageStateFromPersistenceMedium()
> {
> if(EnableDiskViewState)
> {
> DateTime time=new
>DateTime(long.Parse((string)
base.LoadPageStateFromPersistenceMedium()));;
>
> LosFormatter lf=new LosFormatter();
> using(new HashCodeLock(time))
> {
> using(Stream s=LoadPagePersistenceStream(time))
> {
> return lf.Deserialize(s);
> }
> }
> }
> else
> {
> return base.LoadPageStateFromPersistenceMedium();
> }
> }
> protected override void SavePageStateToPersistenceMedium
(object
>viewLightPageState)
> {
> if(EnableDiskViewState)
> {
> LosFormatter lf=new LosFormatter();
> using(new HashCodeLock(_time))
> {
> using(Stream s=SavePagePersistanceStream(_time))
> {
> lf.Serialize(s,viewLightPageState);
> }
> }
>
> base.SavePageStateToPersistenceMedium
(_time.Ticks.ToString());
> }
> else
> {
> base.SavePageStateToPersistenceMedium
(viewLightPageState);
> }
> }
>
> static string GetSiteName(HttpContext context)
> {
> string applmdpath;
>
> try
> {
> applmdpath=context.Request.ServerVariables
["APPL_MD_PATH"];
> }
> catch
> {
> HttpWorkerRequest wr=(HttpWorkerRequest)
> typeof(HttpContext).InvokeMember("get_WorkerReques t"
>
>,BindingFlags.InvokeMethod|BindingFlags.Instance| BindingFl
ags.Public|Binding
>Flags.NonPublic
> ,null,context,new object[]{}
> );
> applmdpath=wr.GetServerVariable("APPL_MD_PATH");
> }
> applmdpath=applmdpath.Replace("/","_");
> return applmdpath;
> }
>
> #region ?????
> override protected void OnInit(EventArgs e)
> {
> //??Request.ServerVariables?????
> GetSiteName(Context);
>
> if(new Random(Guid.NewGuid().GetHashCode()).Next(1000)
==1)
> {
> ClearCacheHandler handler=new ClearCacheHandler
(ClearCacheAsync);
> handler.BeginInvoke(Context,null,null);
> }
>
> base.OnInit(e);
> }
>
> delegate void ClearCacheHandler(HttpContext context);
> static void ClearCacheAsync(HttpContext context)
> {
> string sitename=GetSiteName(context);
> string rootdir=Path.GetTempPath()
+"LightStatePageTemp\\"+sitename+"\\";
> if(!Directory.Exists(rootdir))
> return;
> using(new HashCodeLock("ClearCacheHandler:"+sitename))
> {
> string str1=rootdir+DateTime.Now.ToString("yyyy-MM-dd
HH");
> string str2=rootdir+DateTime.Now.AddHours(-1).ToString
("yyyy-MM-dd HH");
>
> foreach(string dir in Directory.GetDirectories
(rootdir))
> {
> if(dir==str1||dir==str2)
> continue;
> try
> {
> DeleteDirectory(dir);
> }
> catch(Exception x)
> {
> try
> {
> using(FileStream fs=new
>FileStream(Path.Combine
(context.Request.PhysicalApplicationPath,"LightSta teP
>age_ErrorLog.txt"),FileMode.Append))
> {
> using(StreamWriter sw=new StreamWriter(fs))
> {
> sw.Write
(sitename+"???,????"+dir+"??????"+x.ToString());
> sw.Write("\r\n\r\n\r\n");
> }
> }
> }
> catch
> {
> }
> }
> }
> }
> }
> static void DeleteDirectory(string dir)
> {
> foreach(string subdir in Directory.GetDirectories(dir))
> {
> DeleteDirectory(subdir);
> }
> foreach(string file in Directory.GetFiles(dir))
> {
> File.Delete(file);
> }
> Directory.Delete(dir);
> }
> #endregion
>
> private DateTime _time=DateTime.Now;
>
> protected virtual string GetPegePersistenceFileName
(DateTime time)
> {
> return Path.GetTempPath()
> +"LightStatePageTemp\\"
> +GetSiteName(Context)+"\\"
> +time.ToString("yyyy-MM-dd HH")+"\\"
> +Session.SessionID+"\\"
> +Request.FilePath+"\\"
> +time.Ticks.ToString()
> +".txt";
> }
>
> protected virtual Stream LoadPagePersistenceStream
(DateTime time)
> {
> string filePath=GetPegePersistenceFileName(time);
> return new FileStream
(filePath,FileMode.Open,FileAccess.Read);
> }
> protected virtual Stream SavePagePersistanceStream
(DateTime time)
> {
> string filePath=GetPegePersistenceFileName(time);
> try
> {
> return new FileStream(filePath,FileMode.Create);
> }
> catch
> {
> string
>str=filePath.Substring(0,Math.Max(filePath.LastIn dexOf
("\\"),filePath.LastIn
>dexOf("/")));
> CreateDirecotry(str);
> return new FileStream(filePath,FileMode.Create);
> }
> }
> protected void CreateDirecotry(string dir)
> {
> if(dir==null)
> throw(new ArgumentNullException("null"));
> if(dir.Length==0)
> throw(new Exception("???dir"));
> try
> {
> Directory.CreateDirectory(dir);
> }
> catch
> {
> string
>str=dir.Substring(0,Math.Max(dir.LastIndexOf
("\\"),dir.LastIndexOf("/")));
> if(str==dir)
> throw(new Exception("????DIR:"+dir));
> CreateDirecotry(str);
> }
> }
> }
>}
>
>"Frank" <> ????
>news:018f01c3b9da$79c7eb60$...
>> I have a question concerning Viewstate and how it
relates
>> to a Control's event handler (if at all). I did not
think
>> there was any association between a Control's viewstate
>> and an event handler until I attempted to clear
Viewstate
>> from the Page.
>>
>> Here is the problem I am facing: in our system, we do
not
>> want to use Viewstate at all. We have a framework in
which
>> all controls are dynamically created for a page (for
>> better or for worse).
>>
>> However, when we set EnableViewState to false (at any
>> level), there remains some Viewstate generated for the
>> page. Things get worse when we dynamically generate
>> CheckBox controls and add them as child controls to a
>> DataGrid-the Viewstate size becomes very large.
>>
>> I implemented overrides for
>> LoadPageStateFromPersistenceMedium and
>> SavePageStateToPersistenceMedium methods for our base
Page
>> class. Essentially, for Load... I return null and for
>> Save... I do nothing. This works great since Viewstate
on
>> the client now contains 0 bytes in all cases. There is
>> only one problem-the event handlers for the click events
>> on all of our ImageButtons do not work now. How could
this
>> be? Is there some association between a server control's
>> event handler and it's Viewstate? or is this a bug? If
so,
>> what could be a workaround?
>>
>
>
>.
>