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Maybe an article about different type of strings like char*, TCHAR, CString,std::string, etc. that would be great. 
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Actually, I am working on an article about string types and string classes, but I haven't touched it in about a week. I should finish that up since the frequency of string questions (especially about COM and BSTRs) seems to be going up.
--Mike--
Just released - 1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm
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Cool, i`ll be waiting for it.
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Do this instead in order to get at the CString's bytes:
strcpy (fldName0, fldName.GetBuffer(0));
fldName.ReleaseBuffer();
/ravi
Let's put "civil" back in "civilization"
http://www.ravib.com
ravib@ravib.com
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Wrong.
strcpy (fldName0, fldName);
Signature space for rent. Apply by email to....
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The GetBuffer/ReleaseBuffer isn't necessary there. The second argument to strcpy is a const char*, and the CString conversion function (operator LPCTSTR) is called automatically. Your code still works, it's just a bit more complex than necessary.
--Mike--
Just released - 1ClickPicGrabber - Grab & organize pictures from your favorite web pages, with 1 click!
My really out-of-date homepage
Sonork-100.19012 Acid_Helm
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Hi All,
I'm having a problem with the Document/view arch. My problem is this, when a new document is opened, I call my own dll which contains a custom open dialog. This occurs in OnNewDocument. My issue is that if the user cancels out of this dialog without choosing a document, I simply return FALSE out of the OnNewDocument, which causes MFC to destroy the window. When this occurs, the OnCloseDocument is still called and the destructor for my Document class is called, but since the Document object has already been destroyed, i.e. no longer valid, I get a memory access error in the OnCloseDocument and/or the Destructor.
How can I work with this? I've tried several different approaches without much luck
Any suggestions are greatly appreciated. Thanks!
Dan
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Add the bool member m_bInitialized to CYourDoc, set it to false in CYourDoc c'tor. Set it to true in OnNewDocument/OnOpenDocument, but only if everything worked OK. Check m_bInitialized in OnCloseDocument and perform appropriate actions.
Tomasz Sowinski -- http://www.shooltz.com
*** Si fractum non sit, noli id reficere. ***
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Thanks. That was an easy solution. Is this a typical way of dealing with these kinds of issues? Seems kind of a work around a larger issue to me.
Thank you!
Dan
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groover4life wrote:
Is this a typical way of dealing with these kinds of issues?
I guess it is, but I've never experienced the problem you're describing. What exactly are you doing in OnCloseDocument?
Tomasz Sowinski -- http://www.shooltz.com
*** Si fractum non sit, noli id reficere. ***
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I have several Objects that are instantiated upon the opening of a new document to store the data in the formats I need. So I'm creating them dynamically using new. In the OnCloseDocument, I'm cleaning up the "mess" from the current document by checking to see if the pointers are null (basic assertions) and if not null, then I call delete <class> to clean out the memory.
What was happening is the document went away along with the pointers, so those pointers I was cleaning up were pointing out in no-man's land resulting in the memory access error I was having.
Once again, thanks.
Dan
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Just initialize pointers to NULL in CYourDoc c'tor. It's OK to call delete on NULL pointer - it will be no-op. You may also consider using std::auto_ptr.
Tomasz Sowinski -- http://www.shooltz.com
*** Si fractum non sit, noli id reficere. ***
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If i add an IP Address Control to my application and run it exits right after it has started, the dialog doesen't even appear. this happens both in debug and release mode.
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I have what might be a basic C++ question but I'm hoping someone will indulge me.
In my code I allocate a string and then pass it (as a TCHAR*) to a dialog class through the dialog's constructor, where I assign it to a member TCHAR*. The string is later modified in one of the dialog class's functions and I was hoping the changes would be passed back to the calling code, but they are not, the string remains blank ????
Anyone have any idea on how to go about this ?
Thanks in advance
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Check whether you are working with allocated objects and pointer to them. I think in some of your code you allocate a copy and your lost your way. Why don´t you give back your resulting string (as function like "GetResultString()". It also would give you the opportunity to check the DoModal() Result.
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Show us the code where you "assign it to a member TCHAR*" please.
Signature space for rent. Apply by email to....
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Its quite common to find applications with multiple windows or those that spawn other applications or other instances of itself.
For example IE can be launched via some 1. jscript code, or 2. by the user selecting IE to be launched from a toolbar, start menu etc, or 3. launched by some other application.
If launched using 1 or 3 how do I find out which application or which browser instance is the launcher?
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Is it possible to have a window with only close button as like dialog box.if it is so how to specify while create window.
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Yes!
use the resource editor, when creating a dialog template, just remove the Ok button; or derive a class from CDialog and add it (Close button ) or remove the Ok button manually in the OnInitDialog method.
Max.
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Or, if you are using SDI/MDI framework, add this line in
CMainFrame::PreCreateWindow (CREATESTRUCT &cs)
{
...
cs.style = WS_SYSMENU;
return TRUE;
}
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I have several owner drawn CButtons created on a View. these buttosn are used to scale several plots on the same view. Because the buttons do the same thing (just to different plots, depending on which button is clicked) I want to use the same code to perform the actions. Ie. I do not want 6 different button performing the same actions.
What I want to do is when a button is clicked, detect which plot the user wishes to scale depending on the location of the particular scaling button they clicked. I am having a problem getting the location of the button within the view when clicked. Can anyone offer some assistance here???
Thanks
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You can handle WM_COMMAND message in PreTranslateMessage of your view. wParam contains control ID, lParam contains handle to the control sending the message. Having control handle you can get it's rectangle.
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Maybe ::GetMessagePos() can help you to get the position of the mouse click in the click-handler.
Or you could use differnt instances of the same CButton-derived class, having a constructor taking and storing the associated plot number in a member variable.
The click-handler would then work on this plot number.
This probably is the better way to do it.
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