Re: C# Multithreading, GUI hangs while loading - C# Discussion Boards

Re: C# Multithreading, GUI hangs while loading

Justincc31-Jul-07 10:40

31-Jul-07 10:40

Thank you Phil.

I still get the (Not Responding) for a couple seconds when it gets to "pnlNavigation.ContentTree.DataSource = src;" This is a lot of data to load. Since it is taking the most time, shouldn't that part be inside bgWorker_DoWork? ... but it cannot because it is updating the GUI ... so I don't konw what to do.

Re: C# Multithreading, GUI hangs while loading

Justincc31-Jul-07 10:57

Justincc

31-Jul-07 10:57

What do you think about this explanation?

The freezing is because the control is being filled out by the data source, and the only thread allowed to do that is the UI. So, if your data source is large there isn't a way around the 2 seconds pause... unless...

You could manually fill out your control by looping over the data source yourself, and every 10 or so, do a DoEvents() call to keep the UI fresh.

Re: C# Multithreading, GUI hangs while loading

Judah Gabriel Himango31-Jul-07 13:15

Judah Gabriel Himango

31-Jul-07 13:15

justin.moses wrote:
So, if your data source is large there isn't a way around the 2 seconds pause... unless...

If your data set is too large to be displayed all at once, your best bet is filling the dataset a few rows at a time, preferrably in the Application.Idle event handler.

p.s. don't use DoEvents(). It's evil, trust me.

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Re: C# Multithreading, GUI hangs while loading

Luc Pattyn31-Jul-07 7:53

Luc Pattyn

31-Jul-07 7:53

No, that is not how I explained it; the else part executes on the GUI thread and
hence must be fast. Take out everything that does not need to be there, and
have it execute before you call public void LoadCompanies().

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Re: C# Multithreading, GUI hangs while loading

PhilDanger31-Jul-07 7:30

PhilDanger

31-Jul-07 7:30

I'm not quite sure what the LoadCompanies is supposed to be doing, but focus on this part:

if (pnlNavigation.InvokeRequired) //checks to see if the current function is on the same thread as the object
{
      LoadCompaniesDelegate find = new LoadCompaniesDelegate(LoadCompanies); //sets up a recursive call to LoadCompanies?
      this.Invoke(find, new object[] { }); //runs the LoadCompanies on the panel's thread
}
else
{
      pnlNavigation.ContentTree.ParentMember = "ParentId";
      pnlNavigation.ContentTree.ValueMember = "Id";
      pnlNavigation.ContentTree.DisplayMember = "Name";
      pnlNavigation.ContentTree.PrefixMember = "CustomerNumber";
      pnlNavigation.ContentTree.PostfixMember = "CityState";
      pnlNavigation.ContentTree.DataSource = src;
}

As you can see by the comments, the BackgroundWorker will indeed run LoadCompanies on its own thread. You then check for InvokeRequired -- since crossthreaded operations are illegal, this function returns true if the object is on another thread. If it is (which I'm guessing pnlNavigation is a GUI element on the GUI thread), you then call Invoke to call LoadCompanies, which forces it to run on the GUI thread! So you're back where you started, and you have to load from the database AGAIN!

Re: C# Multithreading, GUI hangs while loading

Justincc31-Jul-07 7:36

Justincc

31-Jul-07 7:36

I changed LoadCompanies so as best I can tell, it isn't loading anything twice.
It still has the same (not responding) issue while it loads all the records into the ContentTree.

public void LoadCompanies()
{
if (pnlNavigation.InvokeRequired)
{
LoadCompaniesDelegate find = new LoadCompaniesDelegate(LoadCompanies);
this.Invoke(find, new object[] { });
}
else
{
PROSOCO.Library.Companies.Criteria criteria = PROSOCO.Library.Companies.Criteria.GetCriteria();
BindingSource src = new BindingSource();
PROSOCO.Library.Companies.Nodes nodes = PROSOCO.Library.Companies.Nodes.GetNodes(criteria.NodeCriteria());
src.DataSource = nodes;
pnlNavigation.ContentTree.ParentMember = "ParentId";
pnlNavigation.ContentTree.ValueMember = "Id";
pnlNavigation.ContentTree.DisplayMember = "Name";
pnlNavigation.ContentTree.PrefixMember = "CustomerNumber";
pnlNavigation.ContentTree.PostfixMember = "CityState";
pnlNavigation.ContentTree.DataSource = src;
}

_activeModule = "Companies";
}

Re: C# Multithreading, GUI hangs while loading

PhilDanger31-Jul-07 7:39

PhilDanger

31-Jul-07 7:39

Yes, the double loading was only one problem. Invoke forces it to run on the thread of the object that you called it from.

Re: C# Multithreading, GUI hangs while loading

Judah Gabriel Himango31-Jul-07 10:02

Judah Gabriel Himango

31-Jul-07 10:02

Try changing the LoadCompanies method to this instead:

public void LoadCompanies(DoWorkEventArgs e)
{
  PROSOCO.Library.Companies.Criteria criteria = PROSOCO.Library.Companies.Criteria.GetCriteria();

  BindingSource src = new BindingSource();

  PROSOCO.Library.Companies.Nodes nodes = PROSOCO.Library.Companies.Nodes.GetNodes(criteria.NodeCriteria());

  src.DataSource = nodes;

  e.Result = src;
}

Then change your RunWorkerCompleted handler to look like this:

private void bgWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{ 
   BindingSource src = (BindingSource)e.Result;
   pnlNavigation.ContentTree.ParentMember = "ParentId";
   pnlNavigation.ContentTree.ValueMember = "Id";
   pnlNavigation.ContentTree.DisplayMember = "Name";
   pnlNavigation.ContentTree.PrefixMember = "CustomerNumber";
   pnlNavigation.ContentTree.PostfixMember = "CityState";
   pnlNavigation.ContentTree.DataSource = src;

   ShowLoadingAnimation(false);

    _activeModule = "Companies";
}

Re: C# Multithreading, GUI hangs while loading

Justincc31-Jul-07 10:20

Justincc

31-Jul-07 10:20

It is still freezing the GUI. Let me know if I am doing this how you reccomended or not.

Here is what I have:

        private void LoadCompanies(object sender, EventArgs e)<br />
        {<br />
            pnlNavigation.ShowLoader(true);<br />
            this.bgWorker.RunWorkerAsync();<br />
        }<br />
<br />
        private delegate object LoadCompaniesDelegate();<br />
<br />
public void LoadCompanies(DoWorkEventArgs e)<br />
        {<br />
            PROSOCO.Library.Companies.Criteria criteria = PROSOCO.Library.Companies.Criteria.GetCriteria();<br />
            BindingSource src = new BindingSource();<br />
            PROSOCO.Library.Companies.Nodes nodes = PROSOCO.Library.Companies.Nodes.GetNodes(criteria.NodeCriteria());<br />
            src.DataSource = nodes;<br />
            e.Result = src;<br />
        }<br />
        private void bgWorker_DoWork(object sender, DoWorkEventArgs e)<br />
        {<br />
            LoadCompanies(e);<br />
        }<br />
        private void bgWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) <br />
        {<br />
            BindingSource src = (BindingSource)e.Result;<br />
            pnlNavigation.ContentTree.ParentMember = "ParentId";<br />
            pnlNavigation.ContentTree.ValueMember = "Id";<br />
            pnlNavigation.ContentTree.DisplayMember = "Name";<br />
            pnlNavigation.ContentTree.PrefixMember = "CustomerNumber";<br />
            pnlNavigation.ContentTree.PostfixMember = "CityState";<br />
            pnlNavigation.ContentTree.DataSource = src;<br />
            pnlNavigation.ShowLoader(false);<br />
             _activeModule = "Companies"; <br />
        }

Re: C# Multithreading, GUI hangs while loading

PhilDanger31-Jul-07 10:23

PhilDanger

31-Jul-07 10:23

Stick in some debug statements to see where it is slowing down on.

Re: C# Multithreading, GUI hangs while loading

Justincc31-Jul-07 10:32

Justincc

31-Jul-07 10:32

I get the (Not Responding) for a couple seconds when it gets to "pnlNavigation.ContentTree.DataSource = src;" This is a lot of data to load, however, I thought the background worker would handle that. Right?

Re: C# Multithreading, GUI hangs while loading

Judah Gabriel Himango31-Jul-07 13:13

Judah Gabriel Himango

31-Jul-07 13:13

To eliminate possibilities, temporarily comment all code inside RunWorkerCompleted handler. Does it still freeze?

Beginner Need Help

patkan31-Jul-07 7:03

patkan

31-Jul-07 7:03

Hi all,

I managed to set the forecolor of a Disabled Label by overriding the OnPiant method but how to get automatic text handling (autoelipsis = true & autosize = false) to work ?

T.I.A.

Re: Beginner Need Help

Dave Kreskowiak31-Jul-07 7:29

Dave Kreskowiak

31-Jul-07 7:29

You took over painting of the control, so you've got to determine what conditions have to be met and what to draw for each situation. You can't do "just this piece" and expect the control to draw what you didn't. You either have to draw it all, or let the control draw itself, then you draw over the top of it. Warning! Taking the second route could result in some very unexpected results!

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Re: Beginner Need Help

patkan1-Aug-07 0:11

patkan

1-Aug-07 0:11

I was thinking that someone would kindly enough to share some code with me so i can get faster in my project than your answer as no answer

Re: Beginner Need Help

Dave Kreskowiak1-Aug-07 11:59

Dave Kreskowiak

1-Aug-07 11:59

I pointed you in the right direction, it's up to you to paint the control how you want it. Check into the MeasureString method of the Graphics object you're using to draw with.

patkan wrote:
someone would kindly enough to share some code with me so i can get faster in my project

That's not how CP works. YOU write the code and learn by doing. When you get stuck, you ask specific questions about the problem. You learn nothing by us writing the code for you.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Re: Beginner Need Help

PIEBALDconsult31-Jul-07 11:25

PIEBALDconsult

31-Jul-07 11:25

What's a "Disabled Label"? What do Labels do that can be enabled and disabled? What's the point of setting Enabled to false on a Label? And if you did, why then would you modify what it looks like?

Re: Beginner Need Help

Paul Conrad31-Jul-07 17:47

Paul Conrad

31-Jul-07 17:47

PIEBALDconsult wrote:
What's a "Disabled Label"?

I was wondering that, too. He might be meaning a text box? I am not sure.

"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

Re: Beginner Need Help

patkan1-Aug-07 0:38

patkan

1-Aug-07 0:38

see my reply to PIEBALDconsult

Re: Beginner Need Help

patkan1-Aug-07 0:33

patkan

1-Aug-07 0:33

I've created a user control class, to make the click event for this control to function well (any lazy to set on all the other controls click event), i have to disabled all the label,textbox,images & etc controls

Sorry for poor english

Patrick

Re: Beginner Need Help

PIEBALDconsult1-Aug-07 13:51

PIEBALDconsult

1-Aug-07 13:51

I still have no idea what you mean.

Shadowing and Overriding

sivakumaran_in31-Jul-07 7:02

sivakumaran_in

31-Jul-07 7:02

Can anyone please send me the scenarios, where will we use shadowing and overriding.

Thanks
Siva

Re: Shadowing and Overriding

WillemM31-Jul-07 8:00

WillemM

31-Jul-07 8:00

Normally you don't want to shadow methods in a class, because this hides functionality in a base class. However there are situations where you rather want to shadow methods to make them protected or private.

Overriding is commonly used to extend functionality provided in the methods of the base class. This is done more often in custom controls and classes that extend the .NET framework functionality.

WM.

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Global Assembly Cache &amp; Versioning [modified]

MrEyes31-Jul-07 6:33

MrEyes

31-Jul-07 6:33

Lets say I have an application called Widgets.exe which references, via the GAC, CommonLibrary.dll. This application and its commonlibrary is then deployed to 1000's of devices.

Fast forward a few months and a small bug is found inside commonlibrary. This bug can be fixed without making any changes to Widgets.exe. The relevant developer diligently applies the necessary fixes to CommonLibrary.dll and as a matter of course increases the version number of the library. This is then redeployed, however as Widgets.exe has not changed this is not redeployed.

The problem now is that although the public method interfaces on the CommonLibrary have not changed Widgets.exe is expecting to find version 1.0.0.0 of CommonLibrary in the GAC, however this has now been replaced with v1.1.0.0 (which contains the bug fix). So at runtime a not found exception is thrown by the application.

Now I perfectly understand this and can see why this occurs etc etc. However the problem I have relates to this and how to manage it in the real world. In the real world, Widgets.exe is actually a very large application framework with many executables, assemblies and common libraries. I am trying to find a way to avoid having to redeploy, uninstall, reinstall the application in its entirity should a minor change be made to one of the common libraries.

At the moment to get around this we dont actually use .NET versioning as it should be. At compile time everything in the entire project is compiled to v1.1.0.0 and then we add a revision number to the AssemblyDescription property in AssemblyInfo.cs. This then means we can redeploy single libraries without breaking the dependency/reference chain. The version number would only be increase should a fundamental change be made.

While the ghetto style solution works, it doesnt sit very comfortably with me. So the question is can anybody suggest an alternative/better solution to this issue?

-- modified at 12:39 Tuesday 31st July, 2007

Re: Global Assembly Cache &amp; Versioning

WillemM31-Jul-07 8:08

WillemM

31-Jul-07 8:08

A trick I use is to change the file version not the assembly version. This will prevent older versions of my app from going down with a patch. Of course if you develop an entire new version of the CommonLibrary and your application it's best to update the assembly version as well. This will help with the problem of having an old assembly with the new application.

WM.

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"What? Its an Apple MacBook Pro. They are sexy!" - Paul Watson
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