Registry and TreeView

[Shawn B.]

Greetings,

I'm creating a little program that acts as a glorified Registry explorer.
The TreeView doesn't allow you to show a plus sign unless a node has child
nodes, so I need to determine whether a registry key has subkeys and add a
dummy childnode. The way I'm doing this is to populate the child nodes as
the parent is expanded.

However, there are some serious performance implications. First, when I
pouplate the HKEY_CLASSES_RO OT, it takes 3 seconds to add all the subkeys to
the hive. But if I determine whether those subkeys have subkeys, it takes
49 minutes to populate the HIVE. This is obviously unacceptable. So I'm
left with two choices: 1) figure out a more efficient way to determine and
populate the data, or 2) use C++. Every reg explorer I've ever seen takes
milliseconds to populate the nodes as you expand them, and neither of these
programs are written in C#.

Does anyone here know a better approach? Keep in mind, I'm not populate the
subkeys. I'm only determing whether the subkeys have subkeys (at the level
currently visible) and adding a dummy node so you can get the [+] / [-]
symbol to expand/contract the nodes in the TreeView.

Is it the TreeView that's so slow or the Registry objects in the Win32
namespace? I don't have access to a decent profiler so its hard for me to
tell.
Thanks,
Shawn

[Michael Höhne]

There must be something in your code that causes it to take that long. I
wrote a similar application some time ago in C# running on .NET 1.1. I tried
it out right now and it took about 4 seconds to list all keys in HKCR\CLSID,
and I expect that this is the largest one. Note that I'm also doing the
check for subkeys and use the same approach - insert a dummy node if there's
at least one subkey and add the subkeys in the BeforeExpand event.

Could you post the actual code populating the tree view?

Michael
"Shawn B." <le****@html.co m> schrieb im Newsbeitrag
news:uM******** ******@TK2MSFTN GP09.phx.gbl...

Greetings,

I'm creating a little program that acts as a glorified Registry explorer.
The TreeView doesn't allow you to show a plus sign unless a node has child
nodes, so I need to determine whether a registry key has subkeys and add a
dummy childnode. The way I'm doing this is to populate the child nodes as
the parent is expanded.

However, there are some serious performance implications. First, when I
pouplate the HKEY_CLASSES_RO OT, it takes 3 seconds to add all the subkeys
to the hive. But if I determine whether those subkeys have subkeys, it
takes 49 minutes to populate the HIVE. This is obviously unacceptable.
So I'm left with two choices: 1) figure out a more efficient way to
determine and populate the data, or 2) use C++. Every reg explorer I've
ever seen takes milliseconds to populate the nodes as you expand them, and
neither of these programs are written in C#.

Does anyone here know a better approach? Keep in mind, I'm not populate
the subkeys. I'm only determing whether the subkeys have subkeys (at the
level currently visible) and adding a dummy node so you can get the [+] /
[-] symbol to expand/contract the nodes in the TreeView.

Is it the TreeView that's so slow or the Registry objects in the Win32
namespace? I don't have access to a decent profiler so its hard for me to
tell.
Thanks,
Shawn

[Jason Newell]

Money says he's using Nodes.Add() instead of Nodes.AddRange( ). That
would be key in this kind of situation.

Jason Newell
Michael Höhne wrote:

There must be something in your code that causes it to take that long. I
wrote a similar application some time ago in C# running on .NET 1.1. I tried
it out right now and it took about 4 seconds to list all keys in HKCR\CLSID,
and I expect that this is the largest one. Note that I'm also doing the
check for subkeys and use the same approach - insert a dummy node if there's
at least one subkey and add the subkeys in the BeforeExpand event.

Could you post the actual code populating the tree view?

Michael
"Shawn B." <le****@html.co m> schrieb im Newsbeitrag
news:uM******** ******@TK2MSFTN GP09.phx.gbl...

Greetings,

I'm creating a little program that acts as a glorified Registry explorer.
The TreeView doesn't allow you to show a plus sign unless a node has child
nodes, so I need to determine whether a registry key has subkeys and add a
dummy childnode. The way I'm doing this is to populate the child nodes as
the parent is expanded.

However, there are some serious performance implications. First, when I
pouplate the HKEY_CLASSES_RO OT, it takes 3 seconds to add all the subkeys
to the hive. But if I determine whether those subkeys have subkeys, it
takes 49 minutes to populate the HIVE. This is obviously unacceptable.
So I'm left with two choices: 1) figure out a more efficient way to
determine and populate the data, or 2) use C++. Every reg explorer I've
ever seen takes milliseconds to populate the nodes as you expand them, and
neither of these programs are written in C#.

Does anyone here know a better approach? Keep in mind, I'm not populate
the subkeys. I'm only determing whether the subkeys have subkeys (at the
level currently visible) and adding a dummy node so you can get the [+] /
[-] symbol to expand/contract the nodes in the TreeView.

Is it the TreeView that's so slow or the Registry objects in the Win32
namespace? I don't have access to a decent profiler so its hard for me to
tell.
Thanks,
Shawn

[Shawn B.]

> Money says he's using Nodes.Add() instead of Nodes.AddRange( ). That would

be key in this kind of situation.

Yes I am. I'll have to redo the code for AddRange() if its really that much
more efficient. My code is very simple, the relevant part is:

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();

tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

regKey.Close();
node.Nodes.Add( child);
}

regKey.Close();

tvwRegistryKeys .EndUpdate();
}
Thanks,
Shawn

[Michael Höhne]

Hi Shawn,

I agree with Jason that AddRange is preferable, but your problem clearly is
different. In your foreach loop you do a call to RegistryKey.Ope nSubKey but
don't store the result in any variable:

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);
Now that means that the next block will always operate on the same registry
key:
if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

If this registry key is HKEY_CLASSES_RO OT, then regKey.SubKeyCo unt will take
an enormous amount of time to complete and you're calling it over and over.

Try the following and I'm quite sure that your tree is populated in a few
seconds. After you've verified that, you should go for AddRange to improve
it furhter.

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();
tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
RegistryKey regSubkey = regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regSubkey.SubK eyCount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

node.Nodes.Add( child);
regSubkey.Close ();
}

regKey.Close();
}

Michael
"Shawn B." <le****@html.co m> schrieb im Newsbeitrag
news:OH******** ******@TK2MSFTN GP14.phx.gbl...

Money says he's using Nodes.Add() instead of Nodes.AddRange( ). That
would be key in this kind of situation.

Yes I am. I'll have to redo the code for AddRange() if its really that
much more efficient. My code is very simple, the relevant part is:

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();

tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

regKey.Close();
node.Nodes.Add( child);
}

regKey.Close();

tvwRegistryKeys .EndUpdate();
}
Thanks,
Shawn

[Jason Newell]

Michael,

If you're interested, I threw together a little C# 2005 regedit program
to show you what I'm talking about. I compared it to the Windows
regedit and it's slightly slower but nothing like what you described. I
don't know that you can get much faster with .NET. Let me know if you
have any questions.

You can download the source from my website.

www.jasonnewell.net/public/Examples/Regedit.zip

Jason Newell
Michael Höhne wrote:

Hi Shawn,

I agree with Jason that AddRange is preferable, but your problem clearly is
different. In your foreach loop you do a call to RegistryKey.Ope nSubKey but
don't store the result in any variable:

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);

Now that means that the next block will always operate on the same registry
key:

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

If this registry key is HKEY_CLASSES_RO OT, then regKey.SubKeyCo unt will take
an enormous amount of time to complete and you're calling it over and over.

Try the following and I'm quite sure that your tree is populated in a few
seconds. After you've verified that, you should go for AddRange to improve
it furhter.

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();
tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
RegistryKey regSubkey = regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regSubkey.SubK eyCount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

node.Nodes.Add( child);
regSubkey.Close ();
}

regKey.Close();
}

Michael
"Shawn B." <le****@html.co m> schrieb im Newsbeitrag
news:OH******** ******@TK2MSFTN GP14.phx.gbl...

Money says he's using Nodes.Add() instead of Nodes.AddRange( ). That
would be key in this kind of situation.

Yes I am. I'll have to redo the code for AddRange() if its really that
much more efficient. My code is very simple, the relevant part is:

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();

tvwRegistryKe ys.BeginUpdate( );

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

regKey.Close();
node.Nodes.Add( child);
}

regKey.Close( );

tvwRegistryKe ys.EndUpdate();
}
Thanks,
Shawn

[Jason Newell]

Sorry, I meant Shawn in my last post.

Jason Newell

Jason Newell wrote:

Michael,

If you're interested, I threw together a little C# 2005 regedit program
to show you what I'm talking about. I compared it to the Windows
regedit and it's slightly slower but nothing like what you described. I
don't know that you can get much faster with .NET. Let me know if you
have any questions.

You can download the source from my website.

www.jasonnewell.net/public/Examples/Regedit.zip

Jason Newell
Michael Höhne wrote:

Hi Shawn,

I agree with Jason that AddRange is preferable, but your problem
clearly is different. In your foreach loop you do a call to
RegistryKey.Ope nSubKey but don't store the result in any variable:

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);

Now that means that the next block will always operate on the same
registry key:

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

If this registry key is HKEY_CLASSES_RO OT, then regKey.SubKeyCo unt
will take an enormous amount of time to complete and you're calling it
over and over.

Try the following and I'm quite sure that your tree is populated in a
few seconds. After you've verified that, you should go for AddRange to
improve it furhter.

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();
tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
RegistryKey regSubkey = regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regSubkey.SubK eyCount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

node.Nodes.Add( child);
regSubkey.Close ();
}

regKey.Close();
}

Michael
"Shawn B." <le****@html.co m> schrieb im Newsbeitrag
news:OH******** ******@TK2MSFTN GP14.phx.gbl...

Money says he's using Nodes.Add() instead of Nodes.AddRange( ). That
would be key in this kind of situation.
Yes I am. I'll have to redo the code for AddRange() if its really
that much more efficient. My code is very simple, the relevant part is:

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();

tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

regKey.Close();
node.Nodes.Add( child);
}

regKey.Close();

tvwRegistryKeys .EndUpdate();
}
Thanks,
Shawn

[Shawn B.]

Everytime I run it I keept getting "Object reference not set to an instance
of an object when it tries to return an instance by OpenSubKey(...) ; The
key path looks valid, I'm not sure what to do.

Thanks,
Shawn
"Michael Höhne" <mi************ @nospam.nospam> wrote in message
news:%2******** *******@TK2MSFT NGP12.phx.gbl.. .

Hi Shawn,

I agree with Jason that AddRange is preferable, but your problem clearly
is different. In your foreach loop you do a call to RegistryKey.Ope nSubKey
but don't store the result in any variable:

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);

Now that means that the next block will always operate on the same
registry key:

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

If this registry key is HKEY_CLASSES_RO OT, then regKey.SubKeyCo unt will
take an enormous amount of time to complete and you're calling it over and
over.

Try the following and I'm quite sure that your tree is populated in a few
seconds. After you've verified that, you should go for AddRange to improve
it furhter.

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();
tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
RegistryKey regSubkey = regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regSubkey.SubK eyCount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

node.Nodes.Add( child);
regSubkey.Close ();
}

regKey.Close();
}

Michael
"Shawn B." <le****@html.co m> schrieb im Newsbeitrag
news:OH******** ******@TK2MSFTN GP14.phx.gbl...

Money says he's using Nodes.Add() instead of Nodes.AddRange( ). That
would be key in this kind of situation.

Yes I am. I'll have to redo the code for AddRange() if its really that
much more efficient. My code is very simple, the relevant part is:

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();

tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

regKey.Close();
node.Nodes.Add( child);
}

regKey.Close();

tvwRegistryKeys .EndUpdate();
}
Thanks,
Shawn

[Shawn B.]

Works like a champ. Now I'll just have to figure out what I'm doing wrong.
Thanks,
Shawn

http://www.zenofdotnet.com

"Jason Newell" <no****@nospam. com> wrote in message
news:%2******** *******@TK2MSFT NGP12.phx.gbl.. .

Michael,

If you're interested, I threw together a little C# 2005 regedit program to
show you what I'm talking about. I compared it to the Windows regedit and
it's slightly slower but nothing like what you described. I don't know
that you can get much faster with .NET. Let me know if you have any
questions.

You can download the source from my website.

www.jasonnewell.net/public/Examples/Regedit.zip

Jason Newell
Michael Höhne wrote:

Hi Shawn,

I agree with Jason that AddRange is preferable, but your problem clearly
is different. In your foreach loop you do a call to
RegistryKey.Ope nSubKey but don't store the result in any variable:

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);

Now that means that the next block will always operate on the same
registry key:

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

If this registry key is HKEY_CLASSES_RO OT, then regKey.SubKeyCo unt will
take an enormous amount of time to complete and you're calling it over
and over.

Try the following and I'm quite sure that your tree is populated in a few
seconds. After you've verified that, you should go for AddRange to
improve it furhter.

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();
tvwRegistryKeys .BeginUpdate();

foreach (string key in names)
{
RegistryKey regSubkey = regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regSubkey.SubK eyCount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

node.Nodes.Add( child);
regSubkey.Close ();
}

regKey.Close();
}

Michael
"Shawn B." <le****@html.co m> schrieb im Newsbeitrag
news:OH******** ******@TK2MSFTN GP14.phx.gbl...

Money says he's using Nodes.Add() instead of Nodes.AddRange( ). That
would be key in this kind of situation.

Yes I am. I'll have to redo the code for AddRange() if its really that
much more efficient. My code is very simple, the relevant part is:

if (canContinue == true)
{
string[] names = regKey.GetSubKe yNames();

tvwRegistryK eys.BeginUpdate ();

foreach (string key in names)
{
regKey.OpenSubK ey(path + @"\" + key);
TreeNode child = new TreeNode(key);

if (regKey.SubKeyC ount > 0)
{
TreeNode childNode = new TreeNode("*");
child.Nodes.Add (childNode);
}

regKey.Close();
node.Nodes.Add( child);
}

regKey.Close ();

tvwRegistryK eys.EndUpdate() ;
}
Thanks,
Shawn