:)

Sunil

Hi, I need a notification mechanism for windows shutting down prefferably wthout polling. Any ideas? Thanks in advance.

Sunil

Sorry. That was a typo. What you said is right. I found a solution for this by setting a timeout using the CInternetSession class. However I have ended up with another similar problem. I am reading a file over the network drive using CFIle class. Now if the network drive access is lost (due to any reason) can we get to know this. The read() function continues without breaking. How can this be solved?? Please help...

Sunil

Hi, I am developing a file download utility using MFC. The application downloads a simple file over the internet. During download, is there a way to detect if the network connectivity is lost? Because the CHttpFile->Read function doesn't exit if the connection isn't lost.

Sunil

Hi, How do I download/copy a file from a remote drive to my local drive. I know the use of API "CopyFile" but what I would like to accomplish is download a big file ~20Mb in packets of 4096bytes. Please help...

Sunil

On the lookout for the code I had developed. Will send it ASAP :)

Sunil

THanks Richard

Sunil

Hi, We can achieve this. Please understand the below simple concept with respect to CAD or any drafting utility. We have 2 view perspective always. 1. the world window 2. the view port window. (this is what you need to add in your program) The above can be best understood with the this example: Assume you are taking photograph of a flower in a park. Now, we focus only the flower in the view finder of your camera, and the park in this case forms the world around the flower. So in this case the park becomes the world window and the flower becomes the view window. Similarly the whole drawing in your application is the world window whereas the part of the drawing that is shown to the end user is the view window. You have to make use of the SetViewportOrg method in your application. Please read this http://msdn.microsoft.com/en-us/library/46t66w7t.aspx[^]. Let me know if you need more help, I have done this before but unfortunately cannot find the source for it...

Sunil

Inherit your application view class from CFormView. This enables you to have controls on the view just like you would have on a dialog. For your usage I think this is suitable and it saves time. Check for online samples too...

Sunil

Well there are 2 crude ways to do it: (if you haven't written drivers for your connectivity interfaces ;P ) 1. Enumerate all the network interfaces (non-virtual) and disable them 2. Configure a non-existent proxy server (like 0.0.0.0 port 80) for time being. After you are done with your execution reset this dummy proxy. Ensure you can backup any existent proxy settings if any.

Sunil

Hey munishk, I had developed and application that created approximate of 20 Background workers. All these workers had to update progressbars embedded in a listview for around 20 listview items. However, initially the DoWork event handler used to update the UI which made the UI very sloppy and was sometimes showing a hung behavior. I changed the implementation to make use of Delegates to update the UI and by calling the BeginInvoke method this issue got resolved.

// declare a delegate to update your progress
void delegate UpdateProgressDelegate(object params);

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
//Do Intensive Work
ArgumentClass backGroundCls = e.Argument as ArgumentClass;

  //Now you can do whatever you want to do with passed arguments

  int ctr=0;
  do
  {
      ctr++;
      UpdateProgressDelegate del = new UpdateProgressDelegate(UpdateProgress);
      del.BeginInvoke(ctr, null, null);
  } while (ctr < 10000000);

}

private void UpdateProgress(int ctr)
{
// update progress here
}

This should definitely work and solve your issue.

Sunil

Even when using the Background worker, I advice to make use of BeginInvoke methods to update the user interface elements. This has worked for me big time. Create appropriate delegates for user interface updates and invoke them as and when necessary.

Sunil

Be crisp and clear.

Sunil

Check this link http://www.codeproject.com/Messages/4305065/Re-How-to-Undo-Redo-drawing-operation-in-a-dialog-.aspx[^]

Sunil

Check this link CSerialPort v1.03 - Serial Port Wrapper[^] I am sure this will help you.

Sunil

You need to subclass the dialog so that it can get events.

Sunil

Well Undo/Redo can be handled in an easier and simpler way. There are complex ways of achieving it like double buffering etc but they seem to work exceptionally well in OpenGL. For simple MFC applications you can follow a simple approach. Create a (master)list class that stores the objects to be drawn. As and when you create a new object add it to this list. Maintain another Undo and Redo list. When the user hits on Undo option pop(remove) the last object added from the master list class add this object to your Undo list class. After this re-draw your dialog. When the user hits on Redo option pop(remove) the last object added from the Undo list class add this object to your Master list class. After this re-draw your dialog.

Sunil

This can be achieved by using Win32 API. Create a method and add a Hook to get the windows notifications including logon, logoff, locked, unlocked etc. So if you are using a Winform application include this namespace

using System.Windows.Interop;

In the initialize method add this piece:

            HwndSource source = HwndSource.FromHwnd(this.Handle);
            source.AddHook(new HwndSourceHook(WndProc));

where WndProc is

private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled);

Let me know if you need a detailed implementation. I can help. Also you need to add some interop methods to access the WM_WTSSESSION_CHANGE, WTS_SESSION_UNLOCK etc.

Sunil

Use the Properties window to set the 'Text' property to 0. This could be set as default when your form initializes. When the textbox loses focus add a validation. This should suffice. Alternatively I suppose you can set the text box to accept numbers only.

Sunil

Thanks Dave. But is there a way to hack this. I want the logged on user's environment variables even though the application is invoked as an admin user. I suppose impersonation would not work because the admin account does not fall under local system account...

Sunil