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In my program, i m using CDaodatabase for database connectivity. i then use CDaorecordset to entry/modify data in the database.
My question is::
I do not use DSN anywhere in my program. Does CDaodatabase handle DSN internally. Wat is the better implementation - using DSN or using CDaoDatabase implementation? and wat is the main diff between the two?
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CDaoDatabase constructs a CDaoDatabase object. The path to the database will have to be provided and connection can be opened with Open() method.
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can u point out the difference between connecting vis CDaodatabase and connecting via DSN?
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DSN stands for Data Source Name. Data Source can be a database, spreadsheet, text file etc. We assign DSN to a data source so that irrespective of the data source details and location, we can use that data source; add, modify or delete records, just by knowing it's DSN. From the application use CDatabase class to connect to a data source.
Where as in CDaodatabase, full path to the database needs to be provided to connect.
If the path of the data source changes, if a DSN exists, then changing path in the settings is all that is needed. Code doesnt have to be changed.
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Dear programmers,
We use a device to provide X and Y coordinates similar to a mouse. Using VC++ I create a very small dialog box and refresh its position using the SetWindowPos funtion (at a rate of 120 HZ and setting it as TopMost window). I can also left-click by bringing the mouse to the corner of the small dialog's position and clicking and sending back the mouse cursor to its original position. This way I fully simulate a mouse cursor. Everything works perfect. Except when the window clicks on a menu (i.e. File, Edit, View, Tools, ...). Then the menu that contains all the menu items covers the small dialog box and user cannot see where they are pointing at.
Is there anyway I can highlight menu items when the position of my small dialg box is within the menu item's region? Just like when the mouse moves over the menu item? By the way, remember that the menu item is not a part of my program. It can be in any program.
This is the last part of my project. PLEASE PLEASE if you can think of a solution let me know. I have worked on this project for 4 months. I can further explain the program if you want.
Thank you in advance,
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Hi everyone,
I am using the SetCursor function of VC++ and I want to be able to set the cursor type not just when the mouse is over my program (client area). I want the mouse cursor to change wherever it is. Any suggestion would be most greatly appreciated.
Thanks,
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I have a CFormView that contains about 40 child dialogs, each of which contains at least 5 dialog controls (customer request, not our idea, so don't even think about suggesting another way to do this).
Can anybody come up with a way to allow the user to TAB between these dialogs using the tab key?
Basically I want the user to be able to tab from control to control, as if the chiold dialogs were one great big dialog.
The first person that comes up with something viable with not be verbally abused for one whole week, no matter how absurdly stupid their messages are.
------- sig starts
"I've heard some drivers saying, 'We're going too fast here...'. If you're not here to race, go the hell home - don't come here and grumble about going too fast. Why don't you tie a kerosene rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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Hi,
I think the following procedure should work for what you are trying to do:
1) Override the WM_KEYUP message
2) In the message handler, check if the key pressed is the TAB key
3) If the key pressed is the TAB key, check which control currently has the focus (GetFocus should do the trick)
4) If the control which currently has the focus is the last control on a child dialog, set the focus to the first control on the next child dialog (SetFocus) and then return from the message handler without calling the default WM_KEYUP handler.
5) If the control which currently has the focus is not the last control on a child dialog, return after calling the default handler.
If you need me to provide sample code for this, just ask.
Hope that helps!
Sincerely,
Alexander Wiseman
Est melior esse quam videri
It is better to be than to seem
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I do not think that WM_KEYUP is the correct message. Just go to a dialog and press and hold the tab key. Notice that the focus goes from one control to the next? WM_KEYUP is obviously not being called when the focus is changing. He would have to handle WM_KEYDOWN.
The rest of your suggestion seems probable.
"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!
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PJ,
I had originally typed WM_KEYDOWN in my post, but then I thought that one would only want the change of focus to come after the key had been released, clearly ignoring that focus changes if you hold down the tab key.
Thanks for the correction!
Sincerely,
Alexander Wiseman
Est melior esse quam videri
It is better to be than to seem
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You're in luck, Windows supports what you want to do and I've done something similar myself.
1. Create a placeholder static control in the dialog used for the form view, and make it the same size as the area where the child dialogs will be put.
2. In OnInitDialog(), get the RECT of the placeholder, then destroy the placeholder.
3. Next, create your child dialogs using the RECT you got in step 2 for the dialogs' initial size. VERY IMPORTANT: All child dialogs must have the WS_EX_CONTROLPARENT style. You can set this in the resource editor; you should also turn off the visible style, set them to all be child dialogs (not the default of popup), no caption, and no border.
4. After creating each dialog, use SetWindowPos() to position it in the right place in the tab order. For example, if the child dialogs should be after IDC_FOO in the tab order, do:
wndChildDlg.SetWindowPos ( GetDlgItem(IDC_FOO), 0, 0, 0, 0, SWP_NOMOVE|SWP_NOSIZE );
for each dialog.
After that, It Just Works because the default dialog proc sees the WS_EX_CONTROLPARENT style and does the keyboard handling for you.
--Mike--
Personal stuff:: Ericahist | Homepage
Shareware stuff:: 1ClickPicGrabber | RightClick-Encrypt
CP stuff:: CP SearchBar v2.0.2 | C++ Forum FAQ
----
Kosh reminded me of some of the prima-donna programmers I've worked with. Knew everything but when you asked them a question; never gave you a straight answer.
-- Michael P. Butler in the Lounge
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I did the creation of the child dialogs a little differently, and I also had to set Control parent on the formview template.
Brilliant! Thanks mucho!
------- sig starts
"I've heard some drivers saying, 'We're going too fast here...'. If you're not here to race, go the hell home - don't come here and grumble about going too fast. Why don't you tie a kerosene rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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My C++ program needs to read some structured datasets, or compound datasets just like database tables, but without pre-defined data structure. The structure of a dataset can only be determined at run-time and varies from one dataset to another. I don't know how to define a "generic" data structure so that it can change with datasets dynamically. Can anyone give me a help? Thanks in advance.
Fiona
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Hi,
Could you be a little more specific in your question? When you say "datasets just like database tables" are you actually reading the data from a database, from a flat file, or from some other source? Also, is your question how to read these datasets whose structures are unknown until run-time, or how to make a generic data structure to store them once they have been read?
I can try and help you if you answer these questions.
Sincerely,
Alexander Wiseman
Est melior esse quam videri
It is better to be than to seem
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Hi,
Thanks for your reply. My specific task is to write a data viewer interface to read and display data from files in a particular format. Datasets in a file can be a n-dimensional array of same type, or can be a compound table of different data type, that is what I said like a database table. When I access a data file, I have got some library functions to determine what type of a dataset is, if it's a compound table, the library functions also return how many columns in the table and what data type for each column. For example, if I know a compound table consisting of an "int" type and a "double" type, then I can define a structure like:
struct MyType
{
int a;
double b;
};
and then pass an array of this struct to the "readdata" function to receive the table data. However, as table structures vary with datasets, I cannot pre-define a struct like before. That's what I said I need some generic structure. Actually, the "readdata" library function returns a void pointer to the memory buffer that receives data from the file. The data strcuture on the memory buffer is same as the actual data structure in the table. That's why I want to define a strcut array to recieve data.
Hope this clarifies my problem and hope you can help me sovling this problem.
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Hi,
I apologize for begin so remiss in getting back to you. I've been thinking a bit about your problem and it seems that, since the data formats are dynamic you won't be able to define structs, since you would have to do this at compile-time.
I think perhaps your best approach would be to use void pointers and casting. For instance, you could have a struct which would represent one column like this:
<br />
struct column<br />
{<br />
int dataType;
CPtrArray data;
}<br />
To represent a table, then, you would create an array of columns. If you wanted to use data from a column, you can create a function to detect the dataType, then cast the void pointer to the right data type for use.
On a different note, you could try creating template classes to handle the data. This would probably be a cleaner method than the void* method, but might require more coding.
I'm not sure if, in your implementation, either of these ideas will work. Let me know if neither of them works and I will try to think of something else.
Sincerely,
Alexander Wiseman
Est melior esse quam videri
It is better to be than to seem
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Hi,
Thank you very much for your help. My implementation extends the "column" struct you suggested to a struct holding the whole table instead of columns, eg. an enum array to record column types, and an array to store data size of columns. I am not confident to use void pointer since I read from some source that void pointer is unsafe in C++. So I defined a unsigned char buffer to receive the whole table contents, then retrieve field data from the buffer according to the field type.
Thanks again,
Fiona
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Hi, I'm fairly new to Visual C++. Since recently learning it, I'm still a little unclear of what these parts or the program mean. I've created a list of important keywords and have given (to the best of my knowledge anyway) the meaning of each. If I've incorrectly got the meaning of any of the below wrong, could someone inform me on what to change it to.
The reason I'm doing this is because I know that I need to completely understand each meaning, otherwise learning C++ would be that extra bit harder! If anyone can help me, please do! Thanks, oh and apologies if this message has been asked before!
-All STATEMENTS end with a semi-colon
-DECLARATION is another type of statement which introduces variables to the compiler
-The ASSIGNMENT expression '=' is used to assign a value to a variable
-FUNCTIONS allow you to re-use duplicates of a declaration; meaning less coding
-STRUCTURES are groups of data which are contained within one declaration.
--e.g. :
My Friends Names
||
\/
School -> Joe, Carl, Emily
||
\/
Work -> Andy Philip, Indy
||
\/
Misc -> Ashley, Jake, Zoë
-CLASSES are similar to structures except you can have them public or private
--PUBLIC means the whole program can use the code
--PRIVATE means the code in only accessible within the class
drjake
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Post a specific question.
Kuphryn
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drjake wrote:
CLASSES are similar to structures except you can have them public or private
Wrong. structs members are public by default, classes are private by default
Buy a book, maybe C++ for dummies ? It sounds like you need to start with something that moves over the basics at a reasonably slow pace.
Christian
I have drunk the cool-aid and found it wan and bitter. - Chris Maunder
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Christian Graus wrote:
drjake wrote:
CLASSES are similar to structures except you can have them public or private
Wrong. structs members are public by default, classes are private by default
"Wrong" is not the right answer. Yes, default it is, but:
drjake wrote:
CLASSES are similar to structures except you can have them public or private
which is true, when you use the correct access specifier such as "private:", or "public:"
Bikram Singh
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bikram singh wrote:
"Wrong" is not the right answer.
Yes, it is. He said
bikram singh wrote:
CLASSES are similar to structures except you can have them public or private
That is wrong. It implies that struct members cannot be changed between public or private. Protected didn't even get a mention, but that's another story. As I pointed out, all that changes is what the default is, the meaning of default is the value you get if you don't specify one, so it was implicit in my answer that they could be changed.
Christian
I have drunk the cool-aid and found it wan and bitter. - Chris Maunder
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You would idd better buy a book, but here some answers by examples:
statements:
x = y + z;
Object.SomeFunction(int parameter1, CString parameter2);
CString str = "Some stupid text here.";
Definition:
int x;
double y;
CString str2;
Declaration:
x = 3;
y = 12.3;
str2 = "Hello World!";
(mind definition and declaration can come in 1 line: int x = 4;)
assignment: (see above assignments enough)
Function:
you can call a sequence of code again and again (more specific, a part of code that does something convenient)
int AddTwoInts(int x, int y){
int z = x + y;
return z;
}
Structures generally do not have functions (but they can have them) They mostly only contain data that is part of something bigger. (eg. Struct person could contain a CString name, int height, double weigth);
classes mostly do have functions.
you can consider classes like objects. Objects have data(properties) like integers, doubles and strings. And Objects can do something -> functions.
private, public: Acces level for other classes.
Note: mind ";" => STATEMENTS!
this is probably not entirely correct but gives you some idea to start with I think.
hope this helps.
"If I don't see you in this world, I'll see you in the next one... and don't be late." ~ Jimi Hendrix
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I am having problems with using MSFlexGrid Control. The problem is that i am trying to input in the cells of the FlexGrid at run time by using a floating edit box which pops-up when the user double clicks a pariticular cell. The problem is that edit box is drawn in pixels while the cells of MSFlexGrid are in TWIPS. I couldn't found any conversion formula.
Please tell me how could i change the units of a dialog box (or a particular control) in TWIPS or suggest another way to solve the problem.
Thanks
Naveed
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CMSHFlexGrid m_Table;
CDC *hDC;
hDC = GetDC();
long twips;
CRect aRect;
twips = m_Table.GetCellLeft();
aRect.left = MulDiv( twips, hDC->GetDeviceCaps( LOGPIXELSX ), 1440);
twips = m_Table.GetCellTop();
aRect.top = MulDiv( twips, hDC->GetDeviceCaps( LOGPIXELSY ), 1440);
twips = m_Table.GetCellWidth();
aRect.right = MulDiv( twips, hDC->GetDeviceCaps( LOGPIXELSX ), 1440)\
+ aRect.left;
twips = m_Table.GetCellHeight();
aRect.bottom = MulDiv( twips, hDC->GetDeviceCaps( LOGPIXELSY ), 1440)\
+ aRect.top;
this->ReleaseDC( hDC );
I hope that this works for you.
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