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Join will make the threads join in the "StartIt" method, but the "DoIt" function is running on a different thread.
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I am sorry if I am asking too many questions.
When you say "will make the threads join in the StartIt" which threads are you referring to.
Pl correct me if I am wrong.
What I gathered is that StartIt() is being run by the Main thread and DoIt() is being run by the background thread(Thread 2) and when I use thdTest.Join() the Main Thread stops executing and waits for Thread 2 to finish its job (including writing on lblInfo2) and when Thread 2 is done, then the Main thread picks up from there again and finishes its job.
I have one more question
When I press the button the first thing I see is the MessageBox
Why isn't the label dispalaying the first line of StartIt()
lblInfo2.Text = "Thread 2 started from " + Thread.CurrentThread.Name + "...\n";
before I see the MessageBox
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humayunlalzad wrote: When you say "will make the threads join in the StartIt" which threads are you referring to.
The main UI thread and the thdTest thread.
humayunlalzad wrote: What I gathered is that StartIt() is being run by the Main thread and DoIt() is being run by the background thread(Thread 2) and when I use thdTest.Join() the Main Thread stops executing and waits for Thread 2 to finish its job (including writing on lblInfo2) and when Thread 2 is done, then the Main thread picks up from there again and finishes its job.
That's correct. It will block the UI thread (e.g. freeze the UI) until DoIt() is done executing.
humayunlalzad wrote: Why isn't the label dispalaying the first line of StartIt()
Because the other thread may or may not have set it yet; threads don't execute in any particular order. So if the label was being set in one thread, and looked at in another thread, it's possible that by the time one thread looks at the value, it's not yet set for the other thread.
This is all complex stuff. It gets only more complex once you start having to think about locks to protect variables and data shared between threads.
Here's how you make it simple: don't share memory between threads. That means don't share variables or other data between threads. If another thread needs some data from one thread, make a copy of the data and send him the copy.
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Judah Himango wrote: Thus, setting the lblInfo2.Text inside DoIt() is what's causing the problem
Actually, that won't necessarily cause the problem. Yes, it's a no-no, but often we won't see the actual effects that causes.
I'm more inclined to think it's the MessageBox being shown from the background thread. The MessageBox piggy-backs its message loop on the thread it is called from, and if that's a background thread I have seen all kinds of strange and upsetting behavior from the MessageBox in that situation.
So, my advice is to get rid of the message box. And fix the cross-thread issues. In C# both solutions are trivial.
It has become appallingly obvious that our technology has exceeded our humanity. - Albert Einstein
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Either way, he needs to remove UI code from the background thread.
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Removing the messagebox is not helping, but when I remove the lblInfo2 from the DoIt() method, the problem gets solved.
The question is how do I make DoIt() method write on lblInfo2.
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Hi,
if you need to access a Control from a thread that did not create the Control, then
you need to use Control.InvokeRequired and Control.Invoke()
you can find many examples of this everywhere, including in CP articles; there
is an example at the end of my Sokoban article.
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Use this instead:
lblInfo2.BeginInvoke((ThreadStart)delegate
{
lblInfo2.Text = "whatever";
});
That will invoke the text setter on the correct thread.
If you find yourself doing lots of Control.BeginInvoke or Control.Invoke calls, opt instead to use a BackgroundWorker component. Much simpler and cleaner.
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Thanx guys, this thing is a lil bit tough for me rt now. I will get back to the prob later.
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Ok, continuing on the context of executing reflected code...
Is there any way of adding a web reference in runtime?
Alternatively, what options do I have on invoking a web service without adding the web reference?
Thank you
Gonçalo A.
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Well, you could always create the SOAP request yourself and send it yourself.
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Hi
How can read the characters from Stream and write to a directory. Could any one please tell me.
I tried with this but I am getting error: UnAuthorizedException. Could anyone tell me where is wrong here?
string location = di.FullName + "/ec284451";
DirectoryInfo pub_di = new DirectoryInfo(location);
pub_di.Create();
FileStream fwrter = new FileStream(location, FileMode.Open);
// Allocate byte buffer to hold file contents
byte[] inData = new byte[4096];
// loop through reading each data block
// and writing to the request stream buffer
int bytesRead = respStream.Read(inData, 0, inData.Length);
while (bytesRead >0)
{
fwrter.Write(inData, 0, bytesRead);
bytesRead = respStream.Read(inData, 0, inData.Length);
}
Thanks
Aruna.G
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I think you'll need to create file objects in the directory, writing the bytes to those files. Files can be created using the File.Create static method.
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You can only write on the server, not the client, and ASP.NET is not allowed access to the file system above the root of the web app. So, you have to write to locations underneath the root of your website.
Christian Graus - Microsoft MVP - C++
"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )
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In C# how would you do this? Can you?
I am working in C++/CLI with Windows Forms. No one in the C++/CLI forum was aware of a way to tell where the mouse is pointing when the helpprovider event is called.
I want to have my compiled html help point to a topic specific to where the mouse is pointing (like as a menu item) but I can't seem to determine which control the mouse is hovering over.
My C++/CLI code is below.
private: System::Void FrmMain_HelpRequested(System::Object^ sender, System::Windows::Forms::HelpEventArgs^ hlpevent)
{
Point pt = this->PointToClient(hlpevent->MousePos);
Control^ requestingControl = dynamic_cast(sender);
Control ^ctrl = this->pt;GetChildAtPoint(pt);
Control ^ctrl2 = this->pt;ActiveControl;
Point ptMI = this->menuMainForm->PointToClient(hlpevent->MousePos);
Control ^ctrlMI = this->menuMainForm->GetChildAtPoint(ptMI);
Point ptMenuHelp = this->miHelp->DropDown->PointToClient(hlpevent->MousePos);
Control ^ctrlMenuHelp = this->miHelp->DropDown->GetChildAtPoint(ptMenuHelp);
if( File::Exists(this->pt;helpProvider->HelpNamespace ) == true)
{
Help::ShowHelp(this, this->helpProvider->HelpNamespace);
}
}
ctrl is the form itself and crtl2 is the last active mdichild in my application.
requestingControl returns the form (same as ctrl)and not the item the mouse is over.
ctrlMI and ctrlMenuHelp are undefined.
Hope someone can help 
Programmer
Glenn Earl Graham
Austin, TX
modified on Monday, January 07, 2008 4:03:51 PM
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Hi Glenn
I tried out a few things and here's what I came up with.
If you've got a MenuStrip (e.g. File, Edit, View, etc.) and you're trying to see if the mouse is over a particular menu item (e.g. the File->Exit), you can do it like this:
Point localPoint = fileMenuItem.DropDown.PointToClient(hlpevent.MousePos);
if(exitMenuItem == fileMenuItem.DropDown.GetItemAt(localPoint)) Does this help?
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Wow. Thanks. I updated my code. I tried it but I got an undefined for the control.
Programmer
Glenn Earl Graham
Austin, TX
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I'm not sure I understand. You got null back for the control returned?
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Wouldn't MouseEnter / MouseLeave or whatever work?
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If you wanted an event for every menuitem. I was hoping there was a cleaner way.
PIEBALDconsult wrote: Wouldn't MouseEnter / MouseLeave or whatever work?
Programmer
Glenn Earl Graham
Austin, TX
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Hi,
I have not used it myself, but the way I understand MSDN on Control.HelpRequested event
you should add an event to every Control for which you want to provide help; then in
the HelpRequested event handler the sender parameter points to the Control that currently
needs to show help.
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For the menu dropdown items there is no event for the helpprovider. There is for the file menu itself but it does not tell you which menu item you are currently looking at.
Luc Pattyn wrote: I have not used it myself, but the way I understand MSDN on Control.HelpRequested event
you should add an event to every Control for which you want to provide help; then in
the HelpRequested event handler the sender parameter points to the Control that currently
needs to show help.
Programmer
Glenn Earl Graham
Austin, TX
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OK, I see the problem now: MenuItem is not a Control. However MainMenu and ContextMenu
are, so you could enumerate their menu items recursively to find the one that is currently
selected (MenuItem.Selected property). Not sure what will happen when you move the
mouse up or down, selecting another menu item.
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Thank You very much. It works like a champ! Here is my final code (c++/CLI).
for each ( ToolStripMenuItem ^tmpMS in this->menuMainForm->Items )
{
for each ( ToolStripItem ^tmpCntl in tmpMS->DropDownItems )
{
if (tmpCntl)
{
if ( tmpCntl->Selected )
String ^tmpCntlName = tmpCntl->Name;
OpenHelpForMenuItem(tmpCntlName);
}
}
}
Programmer
Glenn Earl Graham
Austin, TX
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hi.. how do i browse a word document and get the data inside to my richtextBox ?
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