C / C++ / MFC

Re: OnMouseWheel and OnSetCursor interaction

10-Jan-21 22:45

Sorry, I am not sure what that has to do with your original question. If you want to zoom an image based on the mouse wheel then you just need to capture the mouse movement and call your zoom function with suitable parameter values.

Member 1325158811-Jan-21 17:05

Member 13251588

11-Jan-21 17:05

Actually SendMessage(WM_SETCURSOR, 0, 0 or use default) before zooming does the trick.

How to get access to CMyView variables from CMainFrame in MFC

Member 1503370431-Dec-20 6:15

Re: How to get access to CMyView variables from CMainFrame in MFC

31-Dec-20 6:15

Hi Everybody
I have a SDI project. I have created some dynamics ComboBoxes in my toolbar by ".Create" in my CMainFrame Class. My ComboBoxes are working properly in CMainFrame but I want to set some of my variables in CMyView class by void CMainFrame::OnSelchange_My_Dynamics_Combo_1(). I did my best but I was not successful to send/set data to/at CMyView class.
I am beginner in MFC, Please guide me.
Best Regards

David Crow31-Dec-20 8:41

David Crow

31-Dec-20 8:41

Member 15033704 wrote:
...I was not successful to send/set data to/at CMyView class.

What exactly is this supposed to mean?

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Re: How to get access to CMyView variables from CMainFrame in MFC

Member 1503370431-Dec-20 20:47

Re: How to get access to CMyView variables from CMainFrame in MFC

31-Dec-20 20:47

Dear David
I meant: I have some public variables in CMyView class.These variables must be updated from INSIDE the CMyMainFrame class. How can I get access from CMyMainFrame to public variables in CMyView class?
In fact,how can I update public variables I have in CMyView class from CMyMainFrame class?
Best Regads

David Crow1-Jan-21 4:40

David Crow

1-Jan-21 4:40

Member 15033704 wrote:
How can I get access from CMyMainFrame to public variables in CMyView class?

Have you tried calling GetActiveView()?

Re: How to get access to CMyView variables from CMainFrame in MFC

Member 150337041-Jan-21 4:59

Re: How to get access to CMyView variables from CMainFrame in MFC

1-Jan-21 4:59

Yes, dear friend
I write the following code inside MyCMainFrame file :

MyCView*pView = static_cast<mycview*> (GetActiveWindow());

then when I include MyCView.h file inside MyCMainFrame file to use GetActiveView(), then I get CDocument ERROR!!!

Richard MacCutchan31-Dec-20 21:26

Re: How to get access to CMyView variables from CMainFrame in MFC

31-Dec-20 21:26

Your CMyView object should be a member of the CMainFrame, so you just need to add a public method to CMyView that does what you want.

modified 1-Jan-21 6:55am.

Member 150337041-Jan-21 4:52

Re: How to get access to CMyView variables from CMainFrame in MFC

1-Jan-21 4:52

Dear Friend
I did it,Because it seemed very easy, but then I get CDocument ERROR!
After adding #include "CMyView.h" into CMyMainFrame, I get CDocument ERROR!
I searched a lot on the internet, all say use GetActiveView() but it does not work!

Best Regards

Richard MacCutchan1-Jan-21 4:55

Re: How to get access to CMyView variables from CMainFrame in MFC

1-Jan-21 4:55

Sorry, we cannot guess what you are doing. You need to show the code that that you are running, and explain exactly what error(s) you see and where it happens.

Member 150337041-Jan-21 5:06

Re: How to get access to CMyView variables from CMainFrame in MFC

1-Jan-21 5:06

Dear friend
I write the following code inside MyCMainFrame.cpp file :

MyCView*pView = static_cast<mycview*> (GetActiveWindow());
pView->m_CMyView_Pulic_Variable;

To get access to public variables inside CMyview class.

But when I include MyCView.h file inside MyCMainFrame file to use GetActiveView(), then I get CDocument ERROR!

In fact, I just want to change a public variable inside CMyView class from MyCMainFrame.
How can I get access to CMyView class public variables, from MyCMainFrame?

Best Regards

Richard MacCutchan1-Jan-21 5:13

Re: How to get access to CMyView variables from CMainFrame in MFC

1-Jan-21 5:13

Why are you using GetActiveWindow rather than GetActiveView? And what is the exact text of the error you receive and where does it occur?

Member 150337044-Jan-21 7:07

Re: How to get access to CMyView variables from CMainFrame in MFC

4-Jan-21 7:07

Dear Richard
Firstly "HAPPY NEW YEAR"

Many thanks for your help, I was engaged with the CMyDoc error, finally I found it, simply it was redefinition of CMyDoc header in 2 different classes that I never guessed such mistake.

Best Regards

Richard MacCutchan4-Jan-21 9:46

Re: How to get access to CMyView variables from CMainFrame in MFC

4-Jan-21 9:46

Glad you found it. Happy New Year (as much as it can be) to you also.

11917640 Member 4-Jan-21 22:29

11917640 Member

4-Jan-21 22:29

For future use:

MFC Doc/View: How to obtain a pointer to various objects?[^]

Re: How to get access to CMyView variables from CMainFrame in MFC

Member 150337045-Jan-21 2:44

having problem to find an error

5-Jan-21 2:44

Excellent, Thanks

bot-joy28-Dec-20 7:25

bot-joy

28-Dec-20 7:25

Nobita and String | Basics of String Manipulation & Algorithms Practice Problems | HackerEarth[^]

this is the question. my code:

#include<bits/stdc++.h>
using namespace std;

int main()
{
	int t;
	cin>>t;
    std::string s[t];
	for(int i=0;i<=t-1;i++)
	{
   string st;
    getline(cin,st);     
     int l=(int)st.length();
    string s2="",s3="";      
   for(int i=0;i<=l;i++)
   {
       if(st[i]==' '||st[i]=='\0')
       {
           s3=s2+" "+s3;
           s2.clear();
       }
       else
       {
           s2+=st[i];
       }   
   }      
    s[i]=s3;
	}
    for(int i=0;i<=t-1;i++)
    cout<<s[i]<<endl;
    return 0;
}

the error message is saying " your program doesnt print anything. can anyone help me find whats wrong?

jeron128-Dec-20 7:40

jeron1

28-Dec-20 7:40

for(int i=0;i<=l;i++)

Try changing to

for(int i=0;i<l;i++)

You're index is going out of bounds on the st variable 'st[i]', when i is equal to l.
Also, having nested for loops with the same index variable name is tough to read.

"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment
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CPallini28-Dec-20 20:22

CPallini

28-Dec-20 20:22

After the following line

C++

cin>>t;

there are still charactes in the input buffer, hence, the next call to getline gets them.
A commont way to deal with this issue is using cin.ignore (see, for instance What is the use of cin.ignore() in C++?[^]).

"In testa che avete, Signor di Ceprano?"
-- Rigoletto

David Crow29-Dec-20 3:14

David Crow

29-Dec-20 3:14

Have you tried stepping through the code using a debugger? Doing so will let you know in a hurry what is wrong.

gdi+ bitmap save on existing file - showing error

Patrice T30-Dec-20 12:42

Patrice T

30-Dec-20 12:42

In addition to other answers.

Advice: Learn to indent properly your code, it show its structure and it helps reading and understanding. It also helps spotting structures mistakes.

C++

#include<bits/stdc++.h>
using namespace std;

int main()
{
	int t;
	cin>>t;
	std::string s[t];
	for(int i=0;i<=t-1;i++)
	{
		string st;
		getline(cin,st);
		int l=(int)st.length();
		string s2="",s3="";
		for(int i=0;i<=l;i++)
		{
			if(st[i]==' '||st[i]=='\0')
			{
				s3=s2+" "+s3;
				s2.clear();
			}
			else
			{
				s2+=st[i];
			}
		}
		s[i]=s3;
	}
	for(int i=0;i<=t-1;i++)
		cout<<s[i]<<endl;
	return 0;
}

Indentation style - Wikipedia[^]

Professional programmer's editors have this feature and others ones such as parenthesis matching and syntax highlighting.
Notepad++ Home[^]
ultraedit[^]
Enabling Open Innovation & Collaboration | The Eclipse Foundation[^]

Patrice

“Everything should be made as simple as possible, but no simpler.” Albert Einstein

Gopi Nath24-Dec-20 22:21

Gopi Nath

24-Dec-20 22:21

Hello,

I am trying to draw an image (2nd image) over the other image (existing image file - 1st image) using gdi+ bitmap and graphics and then saving (overwriting) the same 1st image file. But saving is not getting done, when i use GetLasError(), it shows error message,
"The process cannot access the file because it is being used by another process"

Here is the code what i am doing.

C++

<pre>Gdiplus::Bitmap *gpBitmap = new Gdiplus::Bitmap(mImagePath1); /// existing image file
Gdiplus::Graphics *gr = Gdiplus::Graphics::FromImage(gpBitmap);

Gdiplus::Bitmap img(mImagePath2); // second image 
Gdiplus::Bitmap* pThumbnail = static_cast<Gdiplus::Bitmap*>(img.GetThumbnailImage(32, 32, NULL, NULL));
gr->DrawImage(pThumbnail, newWpos, newHpos); // drawing the second image on some position of first image

Gdiplus::Status stat = gpBitmap->Save(mImagePath1, pClsid); // pClsid - image encoder set for png output

I tried making copy also, but same issue.

please suggest.

Regards,
Gopi.

Re: gdi+ bitmap save on existing file - showing error

Richard MacCutchan24-Dec-20 23:33