C / C++ / MFC

Keith D9-Jul-03 7:33

Keith D

9-Jul-03 7:33

It's being held down until you get a WM_LBUTTONUP message.

andyg.1019-Jul-03 8:39

andyg.101

9-Jul-03 8:39

hmm tried what you said, what I really want is this, and I couldn't get it to work. I want to execute one bit of code when the button is pressed and then another when it is released. How can I do that?
Andy

Cedric Moonen9-Jul-03 20:17

Cedric Moonen

9-Jul-03 20:17

Just a suggestion: you can perhaps subclass your own button class (derived from CButton) and add handlers for the WM_LBUTTONDOWN and the WM_LBUTTONUP messages. In these functions, send a notification message to the parent.

Hope this helps

andyg.1019-Jul-03 22:35

andyg.101

9-Jul-03 22:35

is there any way to detect that a particular button is being held down. i.e. on the WM_LBUTTONDOWN message, how can I check wether a particular button is pressed in a similar way to say a checkbox?

Andy

ps what notification message do you mean?

ODBC; Multiple rows updated.

Cedric Moonen9-Jul-03 22:58

Cedric Moonen

9-Jul-03 22:58

Another suggsetion is to add handlers for the WM_LBUTTONDOWN and WM_LBUTTONUP messages in your dialog (or view) class. In these functions, test if the position (the point parameter) is on the button.
For this you can use CWnd::ChildWindowFromPoint (take a look at the documentation) and then call GetDlgCtrlID for the CWnd that is returned to see if this is your button.
You can also use flags to keep trace if the button is pressed or not.

Hope this helps

RalfPeter9-Jul-03 7:13

RalfPeter

9-Jul-03 7:13

I have a CRecordset class, which I'm using to update an Access table. I am using MoveFirst() to set the pointer to record 1 and am iterating through the table with MoveNext(). Everytime before moving to the next record, I update a text field. After about the third record, I get a 'Multiple rows were updated' message. If I click 'ok' and keep going with my update program, eventually I come to the EOF. It takes about 1-2 minutes to reach the EOF of a 20 record table on a Pentium 4. What could be the cause the above message? Thx,
Ralf.

ralf.riedel@usm.edu

perlmunger9-Jul-03 7:32

perlmunger

9-Jul-03 7:32

Sounds like a unique identity problem. Does your table have a primary key and if so, are you using it when you do an update? If you are updating with a where clause that uses non-unique fields, then you very well may be updating multiple records. Say for instance you have a table with four columns--ID, NAME, COUNTRY, STATE

If you have two records that look like this:
ID     NAME       COUNTRY    STATE
1      Bob        USA        CO
2      Bob        USA        VA

and you are doing an update like this:

UPDATE MYTABLE SET STATE="OK" WHERE NAME="Bob" AND  COUNTRY="USA"

then you are going to have multiple updates with a single statement. What you should be doing is this:

UPDATE MYTABLE SET STATE="OK" WHERE ID=1

Just make sure that your where clause of your update is using a unique (record) identifier. Does that make sense?

Let me know if I'm off.

-Matt

------------------------------------------

The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall

Anonymous9-Jul-03 10:57

Anonymous

9-Jul-03 10:57

Your rationale makes perfect sense, but I don't think it is the problem. I do not have any primary key set up yet.

What I'm doing is this: I have a blank field that I want to populate with data from several other fields to generate a table with less fields. So, I traverse the entire table and do the updates. I have done this without a problem on two other tables.

I know that my explanation is not much further help, but maybe you have some more ideas. Thank you for your help,
Ralf.

Toni789-Jul-03 13:14

Toni78

9-Jul-03 13:14

What kind of flags are you using to open the recordset?

// Afterall, I realized that even my comment lines have bugs

When one cannot invent, one must at least improve (in bed).-My latest fortune cookie

Anonymous10-Jul-03 4:13

Anonymous

10-Jul-03 4:13

Well, I am using the open() member function upon construction. I do not pass it any arguments. Here's another hint: As I said above, I was able to do updates on two other tables without any problems. It just zipped through the tables (>40,000 records) in less than 30 secs. The third table I have (0.6 million records) was first opened as snapshot. When I changed it to dynaset, it ran (actually still running since yesterday) without the 'Multiple records updated' error message. The problem now is speed. It's been running for almost 20 hours and still on record ~50,000. BTW, when testing, I deleted records from the third, big table (was left with only 20) and the problem with speed persisted. So, I don't think it's a size issue. Does this help? Thank you,
Ralf.

cannot display BMP when resolution is 0

Toni7810-Jul-03 18:07

Toni78

10-Jul-03 18:07

Well, according to microsoft you should not iterate through each element by calling MoveNext() because with large tables it drains the resources. I never ran into this problem because my databases don't have 0.6 million records, but one of the suggestions that I have heard is to use multiple record fetching, or use embedded SQL procedures.

// Afterall, I realized that even my comment lines have bugs

When one cannot invent, one must at least improve (in bed).-My latest fortune cookie

Satyaki9-Jul-03 7:03

Satyaki

9-Jul-03 7:03

Hi Everybody,

I have written a simple dialog based application that displays the image stored in a BMP file. The program works well for all images with uncompressed RGB images having bit depth 24 bpp and horizontal and vertical resolution as some positive value. However, with the files where horizontal and vertical resolution in BITMAPINFOHEADER is 0, the image is not displayed.

In my code, I am doing the following ---
1. Creating a DIB section using CreateDIBSection
2. Creating memory DC from DC of dialog window using CreateCompatibleDC
3. Associating the DIB section with memory DC using SelectObject
4. Copying DIB data into the buffer created by CreateDIBSection
5. Rendering the data using BitBlt/ StretchBlt

What else am I missing?

Any pointers on the same shall be highly appreciated

Regards

John M. Drescher9-Jul-03 8:10

John M. Drescher

9-Jul-03 8:10

I may be missing something but an image with 0 rows and 0 colums has 0 pixels to display....

John

Ryan Binns9-Jul-03 17:10

Ryan Binns

9-Jul-03 17:10

John M. Drescher wrote:
I may be missing something but an image with 0 rows and 0 colums has 0 pixels to display....

I think he's talking about the DPI resolution, not the width/height Smile | :)

[edit]I just read it again, and now I'm not so sure... Unsure | :~

[/edit]

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

John M. Drescher9-Jul-03 17:17

John M. Drescher

9-Jul-03 17:17

Ryan Binns wrote:
I just read it again, and now I'm not so sure...

I felt that way when read the question. A coworker thought that he had an corrupt bitmap and wanted to know how to display it in that case..

John

Satyaki9-Jul-03 22:14

Satyaki

9-Jul-03 22:14

John M. Drescher wrote:
I felt that way when read the question. A coworker thought that he had an corrupt bitmap and wanted to know how to display it in that case..

Sorry for the confusion I had created. Here are the values of interest from BITMAPINFOHEADER

biWidth = 256
biHeight = 256
biXPelsPerMeter = 0
biYPelsPerMeter = 0

I think that the last two values are the cause of the problem. For images in which these values are non zero, they are displayed properly.

Just wondering how Windows Paint is able to display the file with which I am facing the problem!!

Can somebody now say what is happening
Regards
Satyaki