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Richard MacCutchan wrote: what icon you are talking
tray icon - obtained when the program is minimized to tray...
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Hi,
I am using my own gridview derived from Clistview.
My problem is to make the first column always fixed on Horizontal scroll.
Can anybody knows the best solution for this in MFC..
Thank you in advance...
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No, but you might get a better answer if you post it in the MFC forum.
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Windows 7, Visual Studio 2012, MFC, TCP/IP operations using API calls for high data rate application
I am writing a TCP/IP thread to send data to a display device. It is a high data rate output utility and will use overlapped I/O and WaitForMultipleObjects(…) to detect when the outputs are complete. The event array has 23 events and the last 16 are for an array of 16 buffers used to output the data.
The obvious way is to use a switch statement to detect each event returned by WaitForMultipleObjects(…). Can I do this instead?
Note: All this pseudo code is for illustrative purposes only. None is expected to compile much less run.
message_pointer message_address_array[ 16 ];
…
event_detected = WaitForMultipleObjects(
EVENT_ARRAY_SIZE,
mp_common_data->event_array,
WAIT_FOR_ANY_EVENT,
WAIT_TIMEOUT_VALUE );
Switch( event_detected )
{
case EVENT_START_RUNNING:
{… break;}
case IO_EVENT_01:
case IO_EVENT_02:
case IO_EVENT_16:
{
event_index = event_detected – IO_EVENT_01;
message_address_array[ event_index ] = 0;
break;
}
Default {…}
}
Will this concept work? Will it be faster than a separate case for each event? I think it will be easier to maintain.
Or: I just thought of this: Before the switch do this:
event_index = event_detected – IO_EVENT_01;
if( event_index >= 0 && event_index <= LAST_EVENT )
message_address_array[ event_index ] = 0;
else
switch(…) etc, etc
Obviously there would be error checking and significant overhead code. To the core question, in either case, I would be doing event arithmetic, in a fashion. Is this concept valid?
Again, this does not pretend to be working code, just some pseudo statement to illustrate a concept.
Thank you for your time
If you work with telemetry, please check this bulletin board: www.irigbb.com
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I have used similar constructs in the past and they work fine. Whether it is the 'right' way can only be determined by testing.
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The logic is correct as WAIT_OBJECT_0, WAIT_OBJECT_0+1, ... are basically a constants and with switch it is valid to select between constants. However if your application is a high data rate app then be careful with the "linear search" of the WaitForMultipleObjects() function! It is actually documented (check its msdn page) that this function always returns the FIRST signaled handle from the array. This means if you have a "hyperactive" handle near the beginning of the array then the rest of the handles at higher indexes will starve. One technique to defend against this is "rotating" items in the array (or maybe a more fair algorithm is moving the currently signaled handle to the end of the array...).
In case of Overlapped IO I would rather suggest using an IO completion port (shortly: IOCP) that isn't hard to plumb on top of your existing overlapped code, the difficult part is the overlapped IO that is ready in your case.
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Thanks R.M.
pasztorpisti,
When I look at the MSDN page for WaitForMultipleObjects() I do not find that warning. I have seen one topic with two pages that someone found and I did not. Maybe this is one.
However, I think I understand your linear search comment. This will be an almost exclusively output utility. The first N events for the Wait function will be on the lines of, Start running, Stop running, start and stop logging, etc. They will be infrequently used. I plan on 16 events for buffers to be sent out, an arbitrary starting number. The app that sends the data will use them in a strictly circular fashion. It will load the address of a buffer to send and trigger an event. The TCP/IP code in the thread will send the next buffer, the next item whose address is not zero.
When an I/O completes, the event will be triggered, and the address set to zero. These events and addresses will be closely monitored to determine the average backlog of the outgoing data and to determine how well this keeps up with the incoming data. The high data rate stream is 12 megabits per second and there can be multiple stream of it from two or more sources.
I have another app that runs with blocking TCP/IP code and it works, but the blocking I/O causes some difficulties. Now I am researching and designing how I will put the TCP/IP part in a separate thread. I wrote a test app that just starts the thread and get the start/stop/end messages to it. Now for the TCP part.
Thank you for your time
If you work with telemetry, please check this bulletin board: www.irigbb.com
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Here is that paragraph from the msdn doc:
"When bWaitAll is FALSE, this function checks the handles in the array in order starting with index 0, until one of the objects is signaled. If multiple objects become signaled, the function returns the index of the first handle in the array whose object was signaled."
This means, if your first handle is very active then your WaitForMultipleObjects() has good chances to return the first handle even if there are other similarly active signaled handles at higher indexes. You may not even notice this on a strong machines but this behavior may happen only on some slower machines with less cores... Even in that case it isn't really a "BUG", its just starvation that is about as hard to debug as timing related thread-sync issues. Although the paragraph in the msdn doc is not a warning underlined with multiple red lines it is something that can cause you a lot of headaches if your app starts to misbehave just in some special hard-to-reproduce circumstances.
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Now, I have a ActiveX.
And I want to create a SDI, while clicking a button in the activex.
How to do that?
Thanks,
Lux
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I need atlbase.h.
I have Windows 8.1 x64 with VC++ 2008 Express.
How can I get this file? Where is this file?
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ATL[^] is only provided with the purchased versions of Visual Studio, not the Express Editions.
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VC++ 2010 is not giving any option to add web service/web reference.
how can it achive??
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VC++ 2010 wizard do not show Add WEB Reference/Service option when i select MFC project. this option was avaiable in previous version of IDE.
attached link is not useful info for my problem..
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Recently,
I'm using the Ribbon XML to build a button in Word 2007.but i need to custom the image of button.
so,I find something form the url: http://msdn.microsoft.com/en-us/library/office/dd548011(v=office.12).aspx[^]
keywords:OnLoadImage
question: It's only use VBA to solve the problem,I'm realy don't know how to use c++ to solve this.
Please help me and give me some suggestions!
best wash!
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Hi,
Has anyone used unit testing for ATL project?
I am currently exploring ALM in VS 2010 ,Is it really worth the efforts?
jigar
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Windows 7, Visual Studio, C++, MFC and non console type applications that have no windows
Given:
WCHAR destination[ 60 ]
WCHAR source[ 60 ]
Presume: destination has 20 characters to be retained.
What is the best method of copying all the characters that will fit from source into destination?
Easy enough for ASCII, but difficult for this WCHAR novice.
Thanks for your time
If you work with telemetry, please check this bulletin board: http://www.bkelly.ws/irig_106/
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Just use the wcscpy[^] function. There are wide versions of all the character manipulation functions.
Veni, vidi, abiit domum
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Refer back to the OP. The strings have the same maximum length. String destination already has 20 characters so 60 more will not fit.
Function wcscpy() has only two arguments, destination and source. We can write the destination in the format: destination[20] to start there, but there is no way to specify that only 39 of the source characters are to be copied.
However, having seen that, I then found wcscpy_s() with three arguments. We can specify destination[ 20 ], then specify the second argument would be 40.
We can generalize this with a calculated length. But I am unsure about the right functions to use with WCHAR to get the max length and to get the current length. I will try to find that and post again.
Thanks for your time
If you work with telemetry, please check this bulletin board: http://www.bkelly.ws/irig_106/
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Yes, you are so right. Found the page, got the function, using it.
Thank you for taking the time to reply.
Thanks for your time
If you work with telemetry, please check this bulletin board: http://www.bkelly.ws/irig_106/
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Not sure what you mean by 20 characters needing to be retained. No need to walk the string one-by-one...
wcsncpy_s(destination, 60, source, 20);
Will take the first 20 characters of source and copy them to destination. But if you must walk it one-by-one are several ways...
for(i=0; i < 60; i++)
{
WCHAR *current = &source + (sizeof(WCHAR) * i);
destination[i] = *current;
WCHAR current = source[i];
destination[i] = current;
}
I'd never declare a variable in a loop like that, so it's just for illustration. Anyway, you can do whatever logic you want to skip the first 20 chars in destination at that point.
Jeremy Falcon
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