C / C++ / MFC

Coloring scrollbar with DrawThemeBackground

17-Jul-15 3:27

Go back to your study guides and learn how to expose properties of your class objects.

_Flaviu15-Jul-15 1:14

15-Jul-15 1:14

I am struggling for some while to coloring a control scrollbar, with DrawThemeBackground. (any control, no matter what) ... here is the trial:

C++

void CMyControl::OnDraw(CDC* pDC)
{
// draw control
	HTHEME hTheme = OpenThemeData(m_hWnd, L"WINDOW");
//	HTHEME hTheme = OpenThemeData(m_hWnd, L"MFCGridCtrl");
	if(NULL != hTheme)
	{
		if(WS_VSCROLL & GetStyle())
		{
			SCROLLBARINFO si;
			si.cbSize = sizeof(SCROLLBARINFO);
			GetScrollBarInfo(OBJID_VSCROLL, &si);
			CRect rect(si.rcScrollBar);
			pDC->FillSolidRect(&rect, RGB(255, 0, 0));
			HRESULT hResult = DrawThemeBackground(hTheme, pDC->GetSafeHdc(), SBP_LOWERTRACKVERT, SCRBS_NORMAL, &rect, NULL);
			if(S_OK == hResult)
				TRACE("ok\n");
			else
				TRACE("not ok !\n");
		}
		CloseThemeData(hTheme);
	}
}

And I always get not ok ! ... What I'am doing wrong here ? The scrollbar rectangle are ok, I verified ... can you help me ? Thank you.

Jochen Arndt15-Jul-15 1:39

Jochen Arndt

15-Jul-15 1:39

Print the HRESULT code upon failure. It may help to identify the error source (e.g. by printing the corresponding error message using FormatMessage or searching for the code in WinError.h).

_Flaviu15-Jul-15 2:33

15-Jul-15 2:33

I cheked:

C++

E_FAIL Unspecified failure 0x80004005

I am stuck Frown | :(

P.S. But I would try FormatMessage too ...

modified 15-Jul-15 9:05am.

Jochen Arndt15-Jul-15 3:15

Jochen Arndt

15-Jul-15 3:15

Flaviu2 wrote:
But I would try FormatMessage too

That would not help because it will print something similar ("Unspecified error") in the current Windows system language.

I'm sorry, but I have no other ideas.

_Flaviu15-Jul-15 7:06

15-Jul-15 7:06

Thank you for your interest, it's weird that I haven't see any example of how to use DrawThemeBackground function ...

_Flaviu10-Aug-15 23:57

10-Aug-15 23:57

I have tried also:

C++

	HTHEME hTheme = OpenThemeData(m_hWnd, L"SCROLLBAR");
//	HTHEME hTheme = OpenThemeData(m_hWnd, L"WINDOW");
//	HTHEME hTheme = OpenThemeData(m_hWnd, L"MFCGridCtrl");
	if(NULL != hTheme)
	{
		if(WS_VSCROLL & GetStyle())
		{
			SCROLLBARINFO si;
			si.cbSize = sizeof(SCROLLBARINFO);
			GetScrollBarInfo(OBJID_VSCROLL, &si);
			CRect rect(si.rcScrollBar);
			pDC->FillSolidRect(&rect, RGB(255, 255, 0));
			HRESULT hRes = DrawThemeBackground(
				hTheme, 
				pDC->GetSafeHdc(), 
				SBP_UPPERTRACKVERT, 
				SCRBS_NORMAL, 
				&rect, 
				NULL);
			TRACE("HRESULT: %d|%d: OK ? %d\n", hRes, S_OK, hRes == S_OK);
		}
		CloseThemeData(hTheme);
	}

And the result are S_OK now, which is good, however, I have seen nothing colored ... strange ...

CPallini15-Jul-15 1:42

CPallini

15-Jul-15 1:42

I would check the exact value of hResult, however the documentation page is not encouraging (see the comment at the bottom of the page)[^].

_Flaviu15-Jul-15 7:08

Project compiles but VS IDE shows red error lines

15-Jul-15 7:08

I have checked for the first time, but I formatted as int (%d), that's why I saw noise there, not real error returned ... so tricky this DrawThemeBackground function ...

AmbiguousName13-Jul-15 20:40

AmbiguousName

13-Jul-15 20:40

Hello there. I have this project which compiles fine but VS IDE shows that it can not find identifier. Under these identifiers are red lines. WHY is it so ??? Is there some setting I need to check??

This world is going to explode due to international politics, SOON.

Re: Project compiles but VS IDE shows red error lines

Stefan_Lang13-Jul-15 22:02

Stefan_Lang

13-Jul-15 22:02

It is only the VS tool Intellisense that produces the red lines. Intellisense is not as clever as the compiler, so it may have trouble identifying some symbols. This is less of an issue in newer versions of VS (you didn't say which version you have), but it can still happen in code that requires multiple passes to interpret, e. g. code involving #define macros and/or templates.

GOTOs are a bit like wire coat hangers: they tend to breed in the darkness, such that where there once were few, eventually there are many, and the program's architecture collapses beneath them. (Fran Poretto)

Re: Project compiles but VS IDE shows red error lines

AmbiguousName14-Jul-15 0:06

AmbiguousName

14-Jul-15 0:06

I am using VS Ultimate 2013.

Stefan_Lang wrote:
but it can still happen in code that requires multiple passes to interpret

Did you mean compile ? If not, what do you mean by multiple passes to interpret ??

This world is going to explode due to international politics, SOON.

Re: Project compiles but VS IDE shows red error lines

Stefan_Lang14-Jul-15 0:41

Stefan_Lang

14-Jul-15 0:41

I meant interpret in the sense to figure out what a line of code means. Maybe analyze is a better term. Both the compiler and Intellisense need to do this, although for the compiler that's just an intermediate step.

E. g. in a first pass, all preprocessor commands are interpreted, such as #include, #define, and #pragma. After that, most of the code should be plain C/C++, except template definitions: template code is not complete until you specify the template arguments, and that may only happen much later in the code, or, possibly, not at all in the current compilation unit. The purpose of Intellisense (or one of its purposes) is to give you instant feedback on the correctness of code as you type. But it can't give you that feedback for code that requires other code from an entirely different part of the solution.

Re: Project compiles but VS IDE shows red error lines

Jochen Arndt14-Jul-15 0:53

Jochen Arndt

14-Jul-15 0:53

The underlining is done by the editor which is part of the IDE. It parses the source files and tries to find the definitions of variables, functions etc., in the source file itself and the included files. Stefan called this process "interpretation".

The parser (the part of the IDE that does this job) is not a compiler. But it is somewhat similar to a compiler by performing identical or similar tasks to check the source code.

A compiler processes his input files not in one go but uses multiple "passes". The parser might not do this or might not perform always similar to a compiler. This may then lead to the behaviour you are seeing.

Re: Project compiles but VS IDE shows red error lines

Richard MacCutchan13-Jul-15 22:13

How to search large database without SQL or alike. Just asking.

13-Jul-15 22:13

It dependes on the identifier, where in the code it occurs, and what results you get from the build. Without more information it's difficult to make any other comments.

Vaclav_13-Jul-15 7:44

Vaclav_

13-Jul-15 7:44

I am building a small database app on SAM3x8e hardware and decided that C++ will do.
I basically need to find a matching record and have an idea how to do it.
I don't see any timing issues.

I was just curious how the "big boys" do search on VERY large database.
I have heard about hash tables etc.

OK, I can Goggle , but some pointers would be appreciated.
Cheers
Vaclav

Re: How to search large database without SQL or alike. Just asking.

PIEBALDconsult13-Jul-15 8:10

PIEBALDconsult

13-Jul-15 8:10

I'm unclear on what you are asking. Are you using an existing database product? Or are you trying to create your own database system?

Re: How to search large database without SQL or alike. Just asking.

Richard MacCutchan13-Jul-15 22:11

Re: How to search large database without SQL or alike. Just asking.

13-Jul-15 22:11

It is almost impossible to search a database without an SQL like query language, unless you know the exact structure of the data held inside it.

jschell15-Jul-15 10:36

jschell

15-Jul-15 10:36

Vaclav_Sal wrote:
I am building a small database app on SAM3x8e hardware...I was just curious how the "big boys" do search on VERY large database.

First part of that is basically incompatible with the second.

In general the solution for your problem is similar in a very broad way in that one must:
1. Understand the data
2. Understand the searches needed.

The solution(s) are then based on that.

So for example it is pointless to use a hash if you are doing regular expression searches on free form text.

Assembly in C Emu8086 branch table

a random user11-Jul-15 2:46

a random user

11-Jul-15 2:46

Hello there, Im trying to make an assembly program that translates a simple switch case program in c without using and commands related to jg or jt only jmp

I tried making something like this:

org 100h

mov si,3

jmp word ptr [jmptab+si]

case1:
PRINTN "Number One"
jmp endcases

case2:
PRINTN "Number Two"
jmp endcases

case3:
PRINTN "Number Three"
jmp endcases

case4:
PRINTN "Number Four"

endcases:

jmptab:
DW case1
DW case2
DW case3
DW case4

mov ah, 0
int 16h
ret

include magshimim.inc

Where did I go wrong?

modified 11-Jul-15 8:53am.

Re: Assembly in C Emu8086 branch table

Daniel Pfeffer11-Jul-15 9:12

Daniel Pfeffer

11-Jul-15 9:12

[This should really go in QA]

Hint:
a. What is the size of each entry in your jump table?
b. How are you indexing the jump table?

If you have an important point to make, don't try to be subtle or clever. Use a pile driver. Hit the point once. Then come back and hit it again. Then hit it a third time - a tremendous whack.

--Winston Churchill

MFC dialog based application

Member 1182280710-Jul-15 2:37

Member 11822807

10-Jul-15 2:37

Completely new to C++ and have been given a task that includes creating an application that uses CString data from a completely separate .h file.
The CStrings consist of info that I need to be able to copy to the clipboard, then be able to paste that text into word etc. I have set up a button in the application so when that button is pressed it executes what I want it to do (read the CString data and copy it to the clipboard).
For a person of my skill level this is difficult and my colleagues do not have the time to support me on this learning project so I thought I could get some advice and pointers here. Any help would be greatly appreciated. I am an apprentice working in software for 2 months.

Kind regards,
Luke

Re: MFC dialog based application

David Crow10-Jul-15 2:59

David Crow

10-Jul-15 2:59

Member 11822807 wrote:
I have set up a button in the application so when that button is pressed it executes what I want it to do (read the CString data and copy it to the clipboard).

This is what it does or this is what you want it to do?

Member 11822807 wrote:
...so I thought I could get some advice and pointers here. Any help would be greatly appreciated.

So what EXACTLY do you have a question about?

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

Re: MFC dialog based application

Richard MacCutchan10-Jul-15 4:15