C / C++ / MFC

Re: how to change the background color of a checkbox in a list control?

21-May-08 20:32

Thank you for your reply, Hamid.
I'll have a look at it now

tataxin22-May-08 3:12

Re: how to change the background color of a checkbox in a list control?

22-May-08 3:12

it's quite complicated, so I still not success, Cry | :((

but anyway, thanks for your help. I will look at this later

Hamid_RT22-May-08 22:48

Hamid_RT

22-May-08 22:48

Did you see it I guess your problem is solved. Smile | :)

Re: how to change the background color of a checkbox in a list control?

tataxin23-May-08 2:40

Re: how to change the background color of a checkbox in a list control?

23-May-08 2:40

Not yet, Hamid, Frown | :(

If I success, I will notify it here. And if you find something, plz let me know, Smile | :)

tataxin26-May-08 19:32

Put array of characters into an array member of a class

26-May-08 19:32

I did it, not very well but it works.
Actually, I try to do similarly to XListCtrl
All I did here:

I have a class MyListCtr direved from CListCtrl. Then I override OnNMCustomdraw, try to draw the rectangualar with specificed color (black in my case).

The problem is how to catch event mouse click, determine checkbox state and change the drawing. I cannot understand the way XListCtrl do, it seems to register a defined event WM_XLISTCTRL_CHECKBOX_CLICKED, but I'm not sure. And TRACE, what is TRACE macro? hehe

So I did like this: use event NM_CLICK

void CMyDlg::OnNMClickListData(NMHDR *pNMHDR, LRESULT *pResult)
{
	/* get check box state */
	NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
	*pResult = 0;

	if (pNMListView->uOldState == 0 && pNMListView->uNewState == 0)
		return;	// No change

	BOOL bPrevState = (BOOL)(((pNMListView->uOldState &
				LVIS_STATEIMAGEMASK)>>12)-1);   // Old check box state
	if (bPrevState < 0)	// On startup there's no previous state 
		bPrevState = 0; // so assign as false (unchecked)

	// New check box state
	BOOL bChecked=(BOOL)(((pNMListView->uNewState & LVIS_STATEIMAGEMASK)>>12)-1);
	if (bChecked < 0) // On non-checkbox notifications assume false
		bChecked = 0;

	if (bPrevState == bChecked) // No change in check box
		return;	
}

I'd tried some ways but not success until this. Actually, I found it somewhere else.

Dumb Question

bs197721-May-08 14:21

bs1977

21-May-08 14:21

Hi All,

I'm primarily a windows developer , just came across Qt library recently and I need to decide Qt over MFC for a simple GUI implementation on top of real time huge application.I looked around some samples and still confused about how to use Qt. I have real time application (you can imagine as telephony system) where I need to maintain display status of all lines and a common logs (in general display area) separate like Dock Widget. For line display I think it should be like QTableView but data is not coming from DB rather from a thread inside. So, for 100 lines there will be 100 threads sending status and a global thread will be sending status(log) for general display area. You can imagine as left half screen showing just global general logs going on and right half screen will show all line status from top to down ( 1 to 100).
Can anyone please suggest me the best way to handle it.

thanks very much.

Samjiman21-May-08 12:35

Re: Put array of characters into an array member of a class

21-May-08 12:35

Hello.

I'm working on a XPCOM component (so I can't just use std::string) and I need to pass an array of characters into an array which is a member of a class.

(Please ignore that this code is out of context)

class MyClass {
    char val[100][50];
public:
    void drop(char v) { val[0] = v; }
};
 
MyClass Obj;
 
void SomeFunction() {
    char myString[] = "Hello";
    Obj.drop(myString);
}

I get this error: cannot convert parameter 1 from 'char [7]' to 'char'
All I want to do is pass myString to my member function which I want to store the value in the first index of the member array.

Any help would be greatly appreciated, thanks.

David Crow21-May-08 16:00

David Crow

21-May-08 16:00

Samjiman wrote:
I get this error: cannot convert parameter 1 from 'char [7]' to 'char'

drop() is expecting a char, yet you are sending it a char[].

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Put array of characters into an array member of a class

Samjiman21-May-08 23:39

Re: Put array of characters into an array member of a class

21-May-08 23:39

Thanks. I changed to

void drop(char v[]) { val[0] = v; }

But now I get this error -> cannot convert from 'char []' to 'char [50]'.
What should I do?

Rajkumar R22-May-08 0:12

Rajkumar R

22-May-08 0:12

you cannot copy array to another array just using assignment statement, you need to copy element by element using either memcpy, strcpy(if it is null terminated char string).

may be you can change prototype as

void drop(const char v[], int nSize /* pass the size of array*/)
{
  memcpy(&val[0][0], v, nSize);
}

or if the array always has null terminated string

void drop(const char v[])
{
  strcpy(&val[0][0], v);
}

Re: Put array of characters into an array member of a class

Samjiman22-May-08 0:40

Re: Put array of characters into an array member of a class

22-May-08 0:40

Thanks.

void drop(const char v[]) { strcpy(&val[i][50], v); } seemed to have worked.
I can compile the component now. The left most index should be the index to store the string and the right index is the maximum characters (including null char), right?

Rajkumar R22-May-08 0:56

Rajkumar R

22-May-08 0:56

Samjiman wrote:
strcpy(&val[i][50],

where is this "i" declared.

Samjiman wrote:
The left most index should be the index to store the string and the right index is the maximum characters (including null char), right?

strcpy() first parameter is the destination buffers start address, if you specify like "&val[i][50]" the address is ith row 50th element, it starts copying the string from v to end of the row, you need to set the start address as &val[i][0] beginning of the ith row. strcpy doesnot bother about the size of first parameter it copies all the element from second parameter upto the null terminator charater to the buffer whose start address is specified in first parameter. These are basics you may need to learn from C books about pointers, arrays

Re: Put array of characters into an array member of a class

Samjiman22-May-08 5:35

Re: Put array of characters into an array member of a class

22-May-08 5:35

I see. Thanks for your help.

Samjiman22-May-08 0:13

22-May-08 0:13

I can return a passed string with this:

const char *drop(const char *v) { return v; }

But how I can put the passed string into the first index of my array char val[100][50];.
Thanks.

Find control on dialog

Giorgi Dalakishvili21-May-08 10:50

21-May-08 10:50

Hello,

Let's say I have a window created bu external application and I know handle to that window. I need to find control on the dialog with specified class name. So, I know the handle of the dialog which contains the control and I know class name of the control. How can I find it?

One possible way I'm thinking of is enumerating all controls on the form using GetNextWindow and checking control's class using GetClassName function.

Am I on the right track? Is there any better/easier way to do it?

Sorry if my question is stupid, I'm not experienced in Visual c++

Thanks.

Giorgi Dalakishvili

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my articles
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David Crow21-May-08 11:06

David Crow

21-May-08 11:06

How about FindWindowEx()?

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Giorgi Dalakishvili21-May-08 11:18

21-May-08 11:18

Thanks, I'll try it. As I have practically no experience in win api, I was not sure whether it would find control or not.

Thanks again.

Giorgi Dalakishvili

#region signature
my articles
#endregion

Force Code21-May-08 11:21

Force Code

21-May-08 11:21

Giorgi Dalakishvili wrote:
One possible way I'm thinking of is enumerating all controls on the form using GetNextWindow and checking control's class using GetClassName function.

I would use EnumChildWindows and check for the ctrlID for each Child Window using GetDlgCtrlID. The Ctrl ID will be unique and won't change.

Giorgi Dalakishvili wrote:
I'm not experienced in Visual c++

Well, it seems you already knew about EnumChildWindows and even how to invoke it from C#:

http://www.codeproject.com/script/Forums/View.aspx?fid=1649&msg=2558300[^]

Giorgi Dalakishvili21-May-08 11:25

21-May-08 11:25

Force Code wrote:
I would use EnumChildWindows and check for the ctrlID for each Child Window using GetDlgCtrlID. The Ctrl ID will be unique and won't change.

GetDlgCtrlID returns int, how would you check for class name?

Giorgi Dalakishvili

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Force Code21-May-08 11:37

Force Code

21-May-08 11:37

Giorgi Dalakishvili wrote:
GetDlgCtrlID returns int, how would you check for class name?

I assumed you were just trying to locate a specific control, and using the classname for that purpose. If you're just looking for any control of a certain class, then of course you can use GetClassName.

Why would you think to use GetNextWindow as opposed to EnumChildWindows?

Giorgi Dalakishvili21-May-08 11:50

21-May-08 11:50

Yes, I'm trying to locate a specific control but I won't know its id in advance, I'll only know its class name.

Force Code wrote:
Why would you think to use GetNextWindow as opposed to EnumChildWindows?

I just forgot about EnumChildWindows. Should I prefer it to GetNextWindow? Is there any significant difference between them?

Giorgi Dalakishvili

#region signature
my articles
#endregion

Force Code21-May-08 12:14

Force Code

21-May-08 12:14

Giorgi Dalakishvili wrote:
Yes, I'm trying to locate a specific control but I won't know its id in advance, I'll only know its class name.

You can get the control ID with Spy++, or I imagine lots of other utilities as well. If you know enough about the application, then I guess the classname would suffice (also a unique control ID is just convention, and not something that's enforced.)

Giorgi Dalakishvili wrote:
I just forgot about EnumChildWindows. Should I prefer it to GetNextWindow? Is there any significant difference between them?

You mentioned it three days ago in the C# thread, and even supplied the msdn link. AS far as differences, to me its just more compact than calling GetWindow or GetNextWindow in a loop. Also, the documentation says,

"[EnumChildWindows] is more reliable than calling the GetWindow function in a loop. An application that calls GetWindow to perform this task risks being caught in an infinite loop or referencing a handle to a window that has been destroyed. "

EnumChildWindows does actually return all descendants of a given window and not just immediate children.

Rajesh R Subramanian21-May-08 20:21

Rajesh R Subramanian

21-May-08 20:21

Giorgi Dalakishvili wrote:
I just forgot about EnumChildWindows. Should I prefer it to GetNextWindow? Is there any significant difference between them?

In this case, FindWindowEx() should be best for you. Because, you just don't need an enumerated list of all the child windows of the dialog. FindWindowsEx() will just return a handle which pinpoints at the control of your interest. Smile | :)

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