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I've read the article WM_KILLFOCUS is the wrong time to do field validation over and over again and I agree with it in general.
I've mentioned this to my company's design department and they said that the usablity requirements of the feature dictate that we must validate when the user tries to leave the control otherwise, then user can run into all sorts of problems in the future. I've been tempted to tell them to re-design the form so the requirement is not necessary but if the company did that, it would cost a lot of money in the form of time to not only re-design the form but to also re-code it.
What I'm currently doing now is in OnKillFocus, I'll determine that the control's data is invalid, then I'll post a WM_USER message to the form. When the form responds to the WM_USER message, it shows the appropriate messagebox and sets focus to the control. It gets messy though when the user selects a different property page. Also if the user uses an accelerator key to run the button, OnKillFocus is never called.
One idea I'm working on is to write a global catch of WM_LBUTTONDOWN and to catch accelerator key messages as well as the tab message. Then send a "CanKillFocus" message to the control that has focus and to the control's parent. If the response is false, then I would just eat the message. Then I could write a custom SetFocus method in all my controls (They all use a common template) and have it to do the same. I would just have to communicate to my programming department colleagues that they need to use new functionality to set focus to controls--especially on a form that does focus validation.
I'm currently putting together a dummy app to see if this idea would really work or if it would cause even more problems in the future.
Peteman_R
Boise, Idaho
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PeteMan_R wrote:
they said that the usablity requirements of the feature dictate that we must validate when the user tries to leave the control
They're forgetting that the user may be FORCED to leave the control (without wanting to do so), eg: when another application (eg: an IM window) demands focus.
/ravi
My new year's resolution: 2048 x 1536
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ravib@ravib.com
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Thanks all -
I found one solution. My Onkillfocus checks whether the current focus is on any of the data entry controls. If yes, then only validate else skip the validation. In this way, user is not forced to erase the wrong data if he wishes to leave the screen.
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Hi everyone,
Is there any way to send infromation to a computer in a local network using the mac address of the network adapter?
If there is...Tell me please!
Cheers,
Thanks.
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I'm not sure what you mean by "send information".
Communication between networked computers is usually done using some form of client/server communication, although there are other less-optimal ways (eg: polling a shared resource) to send information.
/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
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Hi,
Ravi wrote:
I'm not sure what you mean by "send information".
For example sending a string to a client.
using mac address,
Is it possible?
Cheers,
Thanks.
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You can't magically send data to a MAC address. A transmission protocol needs to be established between the sending and receiving computers.
See Sébastien Lachance's excellent article[^] for a set of classes that makes this easy to do.
/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
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I have written a code for putting a text over an image using CxImage but when I'm putting it on the right side of the image the end of the text dissapears just like if the image doesn't end where I see it end, but a little further to the right.
This problem does not exist when I put an image over another image in the right side, probably because it must calculate the extra 'space' it has.
Can anyone tell me why and how to fix it? 
Thanks
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I have one abstract class and several classes which are all derived from the abstract class.
How can I create all of those classes without calling each constructor? The way I found is via the CRuntimeClass::CreateObject method and enter the RUNTIME_CLASS(Classname) in an array. So I can easily add classes by simply adding them to an array. Is there another solution, because I am not allowed to have any parameters within my constructors with this solution?
And how can I detect by a keyword which class to create? The keywords are static member variables in the classes. How can I dynamically compare those keywords with a given keyword without creating the classes and then instanciate the appropriate class?
Thanks for any help.
Konrad
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first, to create a class object, you will need to eventually call the constructor.
AFAIK, you can't really create an array of types (if I understand you correctly ); RUNTIME_CLASS takes an already created object;
Have a look ( google ) at the factory design pattern.
it goes something like :
class CFactory
{
static CYourAbstractClass* CreateYourDerivedClass( int iWhichClass );
};
...
CYourAbstractClass* CFactory::CreateYourDerivedClass( int iWhichClass )
{
switch ( iWhich Class )
{
case 0:
return new FirstDerivedClass;
case 1:
return new SecondDerivedClass;
default:
return NULL;
}
return NULL;
}
Maybe, there are some template wizard that have a solution for you ...
Maximilien Lincourt
Your Head A Splode - Strong Bad
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 I want learn game programming by visual c . How i can begin it;
i am good in c++ and vc but not :-Oproffesional and not begineer
any one can help me ????:->
![Rose | [Rose]](https://www.codeproject.com/script/Forums/Images/rose.gif)
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Hi,
I want to send a WM_NOTIFY message from a class derived from CMSFlexGrid
to its parent window, but the message is always reflected back to the FlexGrid (tested with Spy++) and the handler for this message in the parent Window (Dialog) is never called. I think this is normal, since the the FlexGrid is an ActiveX(OLE) Control, but I need the message to be processed by the parent window.
Is there a way to disable this behavior, before sending the message??
Thanks in advance!
Tobi
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can any one tell me good book on borland c++ builder
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I'm writing a .dll, I want to show an editbox to an focused window but I don't know how to. Please show me how to both in MFC and Win32 .thankx
Then I kiss Ur eyes and thank God we're together
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is ur Edit Box in the Dll!!
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
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But in the dll I don't have a dialog or user interface. when user do something press 'A' for examble, I want display a listbox in the window is having focused.
Then I kiss Ur eyes and thank God we're together
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in one of my forms, there is an edit box for numeric characters. Everything is good when typing characters from keyboard but when i paste some thing that like "asads" it directly pastes it.
is there a basic solution or do i have to check after "PASTE" is there any unwanted characters and remove them...
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Check the entry in your EN_UPDATE handler. If the user entered invalid characters reset the text back to the last valid entry.
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04
Within you lies the power for good - Use it!
Honoured as one of The Most Helpful Members of 2004
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in one of my forms, i'm using 2 datetimecontrols. One of its format is "Short Date" there is no problem about this. Other one must be "Time", i set it to time and compile. Everything is great, working but there is a problem. When i go to resources and check it, "Time" is changed to "Short Date" and when i compile it it acts like "Short Date".
is there a solution or do i have to change it everytime
i am using visual studio 7.0
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I know what you're talking about, I've had the same thing happen to me. You can try changing the style on WM_INITDIALOG by doing something like: dtp.ModifyStyle(0, DTS_TIMEFORMAT);
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Thanks for your help Mark.It works. its an easy solution. but i cant think it
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Hi,
I am making a customized Save as Dialog. I am unable to get the hierarchy of the files and directories in the Combo Box.
How will i get the browse information, that is the hierarchy of all the files and the folders, in the dropdown Combobox ???
Anu
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Can I get a tip on what I need to change in this program
exams=50% quizzes=10% daily=10% assign=30%
include <stdio.h>
void main (void)
{
double gpa,exam,quiz,assign,prof;
printf("\n enter the exam grade:");
scanf("%lf", &exam);
printf("\n enter the quiz grade:");
scanf("%lf",& quiz);
printf("\n enter the daily grade:");
scanf("%lf",& daily);
printf("\n enter the assign grade:");
scanf("%lf",& assign);
gpa=((exam*.6)+(quiz*.4)+(daily*8)(assign*.6);
printf("\n the gpa is %.2lf", gpa);
}
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Compile it, the compiler wil give you the tip.
<italic>Work hard, Work effectively.
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