CFile - C / C++ / MFC Discussion Boards

Stephane Rodriguez.8-May-03 1:29

8-May-03 1:29

NHM wrote:
how can the VC# dll receive messages... in vc++6.0 PreTranslateMessage is the answer... n in VC#?

A Windows Forms app has a UI thread which processes windows messages just like any WIN32 app with a message loop. Any Windows Form control has a virtual WndProc method that can be overridden to respond accordingly.

The other way, a C# app can send a WIN32 message to any window (for instance a window from a VC++6 app) by using the [DllImport] P/Invoke technique :

[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern int SendMessage(IntPtr hWnd, int msg, int wParam, int lParam);

Re: Passing around params VC++6.0 VC#

NHM8-May-03 3:18

NHM

8-May-03 3:18

if i override WndProc in the windows form (C# dll) then when i try to open it through the VC++ 6.0 App it stops execution... just gives a runtime error... ideas? thanks 4 your suport .S.Rod!

Re: Passing around params VC++6.0 VC#

Stephane Rodriguez.8-May-03 3:29

Stephane Rodriguez.

8-May-03 3:29

NHM wrote:
when i try to open it through the VC++ 6.0 App

What do you mean ?

Has it anything to do with the debug session ? Do you mean you are trying to access the C# WndProc implementation from your VC++ debug session ? No need to go further, you simply can't.

Or do you mean you are processing the message in the C# wndproc implementation and then it fails? If the code fails at this point, then it might be helpful for those listening if you post the code.

Re: Passing around params VC++6.0 VC#

NHM8-May-03 3:45

NHM

8-May-03 3:45

i've just overriden the WndProc... no code added to the base override...

this is what i have...

a) a vc++ 6.0 Mdi app (.exe)
b) a vc# dll with:
- class A (interface) (cominterop)
(i have to call some methods and access some properties)
- class B (windows form)

in the vc++ 6.0 mdi app i create an instance of classA
then i call a method from class A wich does this:

public void SomeThing()
{
Form1 f = new Form1();
f.Show();
}

and this is what i intended to do:

public void SomeThing( Form parent)
{
Form1 f = new Form1( Form parent);
f.MdiParent = parent;
f.Show();
}

i just want to say to the VC# winForm that his container is the VC++ 6.0 APP

what can i do?

Re: Passing around params VC++6.0 VC#

Stephane Rodriguez.8-May-03 3:51

Stephane Rodriguez.

8-May-03 3:51

The simplest thing that comes to my mind is to reparent the C# form window.
This can be done with simple things :
- the window handle of the C# form is obtained using this.Handle if you use managed code. Otherwise, from C++ code you can enum windows or use FindWindow(...) with a particular caption to get that window handle.
- then, use WIN32 ::SetParent(hwndForm, hwndNewParent /*MDIapp frame window hande*/) to reparent the form.

Good luck!

WS_CLIPSIBLINGS.........

Neha8-May-03 0:15

Neha

8-May-03 0:15

Hi,

I have a image control(child of main window) in a window,which is created with WS_CLIPSIBLING flag.
But when i move some other window over my main window. image control receives WM_PAINT message. How can i avoid receiving the WM_PAINT message for the image control?

Re: WS_CLIPSIBLINGS.........

jhaga8-May-03 2:59

jhaga

8-May-03 2:59

I dont know any way to avoid recieving WM_PAINT but
you can ignore (comment code out) where you handle
the message.

jhaga

CFile

macmac387-May-03 23:19

macmac38

7-May-03 23:19

Why this generates "test.pmjaaaaYYYYY" as output??

  <br />
<br />
<br />
<br />
<br />
   char* szBuffer = NULL;<br />
   int i = 0;<br />
<br />
   CFile f;<br />
          <br />
   if( f.Open ("F:\\test\\id.txt", CFile::modeRead ) ){  <br />
	   try {                           // Get the size of the file.    <br />
		   i = f.GetLength();        // Create buffer to hold filedata.    <br />
		   szBuffer = new char[i];   // Read in the file data <br />
		      <br />
		   if(szBuffer != NULL)<br />
			   <br />
		   f.Read(szBuffer, i);       <br />
		   f.Close();                  // Close the file. <br />
<br />
            } <br />
	   <br />
	   catch (CFileException *e)  <br />
	   {    <br />
		   AfxMessageBox ("Error!");    <br />
		   e->Delete();  <br />
	   } // end TRY-CATCH<br />
<br />
   } // end IF<br />
   <br />
     CString csPath = szBuffer;<br />
	  <br />
     SaveStream(csPath);<br />
<br />
	 if(szBuffer != NULL)  <br />
          delete [] szBuffer;<br />

Thanks, Mark

Re: CFile

Neville Franks8-May-03 0:08

Neville Franks

8-May-03 0:08

The file you are reading won't have a 0 terminator. Try:

szBuffer = new char[i+1]; // Read in the file data 
szBuffer[i] = 0;

Neville Franks, Author of ED for Windows. www.getsoft.com
Make money with our new Affilate program

Re: CFile

macmac388-May-03 0:36

macmac38

8-May-03 0:36

Now it works. Will a "Detected memory leaks!" be a problem?

Thanks, Mark

Re: CFile

Neville Franks8-May-03 1:56

Neville Franks

8-May-03 1:56

macmac38 wrote:
Will a "Detected memory leaks!" be a problem?

Short answer, Yes.

Also if you are reading a fixed length file, you should write using fixed length routines, not a stream. ie, don't mix file i/o types unless you have to.

Neville Franks, Author of ED for Windows. www.getsoft.com
Make money with our new Affilate program

Re: CFile

Hari Krishnan (Noida)8-May-03 0:46

Hari Krishnan (Noida)

8-May-03 0:46

Hi,
As, franks mentioned, it happens because, the output is not null-terminated. Here's the code snippet, which very well read your file, without any memory leaks.

-----------------------------------------------------------
CFile oFile;
DWORD dwFileLength;
if(oFile.Open("F:\\test\\id.txt", CFile::modeRead))
{
try
{
CString strBuffer;
dwFileLength = oFile.GetLength();
LPTSTR szBuffer = strBuffer.GetBufferSetLength(dwFileLength);

oFile.Read((LPVOID)szBuffer, dwFileLength);
oFile.Close();
CString csPath(strBuffer);
strBuffer.ReleaseBuffer();
}
catch(CFileException *e)
{
AfxMessageBox ("Error!");
e->Delete();
}
}
-----------------------------------------------------------

regards
~Hari~

Carray doubt

doctorpi7-May-03 22:38

doctorpi

7-May-03 22:38

Sorry if this is a silly question, but I'm a little confused.
I've got a class MyClass and I want to have a CArray of MyClass objects in the Doc class of my application.
Ex:
In CMyAppDoc
CArray <<cmyclass,cmyclass>> m_myArray;

My question is.
How I have to declare and have acces to the array to touch the values of it directly (by reference) in the view?
CMyAppView
?????

Best Regards
Dr. Pi

Re: Carray doubt

Dr-Kuulun7-May-03 22:54

Dr-Kuulun

7-May-03 22:54

Hi,

i had the same problem and it seems to be impossible.
i created a lot of instances of my class with 'new' and than i stored the pointers in an CObList or CObArray.
This array stores only the pointers, so clean the memory up ('delete pClass') when deleting the array.

Dr-Kuulun

Re: Carray doubt

Cedric Moonen7-May-03 22:57

Cedric Moonen

7-May-03 22:57

Try this:

CArray<CMyClass*,CMyClass*&> m_MyArray;

And to acces any data:

CMyClass* Temp = m_MyArray[i];<br />
Temp->DoSomething();

Hope this helps !
Ced

Re: Carray doubt

jhwurmbach7-May-03 23:15

jhwurmbach

7-May-03 23:15

You are probably better off using the standardized std::vector class:
std::vector< CMyClass > m_myArray;

... now you can fill the vector e.g. using push_back()...

And now you can use
CMyClass c = GetDocument()->m_myArray[0];
to access the first data item in the associated document.

Hope this helps

My opinions may have changed, but not the fact that I am right.

Re: Carray doubt

David Crow8-May-03 3:29

David Crow

8-May-03 3:29

I have something similar in one of my projects.

class CMyDoc : public CDocument
{
public:
void GetAddressList( CDWordArray *pAddresses );

private:
CDWordArray m_arrAddresses;
};

void CMyDoc::GetAddressList( CDWordArray *pAddresses )
{
pAddresses->RemoveAll();

pAddresses->Append(m_arrAddresses);
}

void CMyView::OnUpdate(CView* pSender, LPARAM lHint, CObject* pHint)
{
CMyDoc *pDoc;
CDWordArray arrAddresses;

pDoc = GetDocument();
pDoc->GetAddressList(&arrAddresses);
}

Hope this helps, or at least gives you an idea.

Refresh problem...

Neha7-May-03 22:24

Neha

7-May-03 22:24

Hi,

I have a bitmap displayed in a window. When some other window is moved over this window. This bitmap gets refreshed,i don't want that to happen. I don't want to create bitmap with WS_CLIPSIBLINGS style. Any idea how can i avoid the bitmap to get refreshed?

Regards

Re: Refresh problem...

Ernest Laurentin8-May-03 3:59

Ernest Laurentin

8-May-03 3:59

Why? why did you say (write) that you don't want it to get refreshed? (just curious!)

ÿFor the bread of God is he who comes down from heaven and gives life to the world. - John 6:33

Bitmap processing

sooyewguan7-May-03 21:33

sooyewguan

7-May-03 21:33

Could anyone who are good in image processing give me some advises for my question:

1. How to do an 'edge detection' on a bitmap?
2. How to change the contrast of a bitmap?

Confused | :confused:

thanks you.

Re: Bitmap processing

C^hris L^osinger8-May-03 3:07

C^hris L^osinger

8-May-03 3:07

1. apply a convolution filter (see "Laplacian")
2. to raise contrast, lower the low pixel values, raise the high pixel values. to lower contrast, do the opposite.

-c

C^hris L^osinger
Smaller Animals Software

small ques about handles

r i s h a b h s7-May-03 18:19

r i s h a b h s

7-May-03 18:19

dear all,
how can i get the handles of controls present in my dialog.
Confused | :confused:

thanx

Re: small ques about handles

_crs_7-May-03 19:51

_crs_

7-May-03 19:51

hello,

I don't know exactly what you want but:

1. if you are programming MFC and you need a CWnd pointer to an edit box(his resource id is for example IDC_EDIT1) or any other control in your dialog (dialog1) :

dialog1.GetDlgItem(IDC_EDIT1);

2. in old windows programming style

GetDlgItem(dialog1, IDC_EDIT1);

where dialog1 is a handle to your dialog and IDC_EDIT1 is the resource id of the control

for both functions the return value is what you want....

Re: small ques about handles

r i s h a b h s7-May-03 21:36

r i s h a b h s

7-May-03 21:36

thanx a lot _crs_
thats exactly what i was asking for,
but how do i get the handle of dialog box (dialog1 in ur example)

Re: small ques about handles

David Crow8-May-03 3:33

David Crow

8-May-03 3:33

Use CWnd::GetSafeHwnd() for any window.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.