Docking windows in Visual C++ .NET

[y_notm]

can anybody show me how to do this, please? preferably code I can include fairly easily into an existing MFC application.

[freestyle]

1. In you .H file add in the following line

<pre>afx_msg void OnWindowPosChanging(WINDOWPOS* lpwndPos);</pre>

after the Generated message map functions part.

2. In your BEGIN_MESSAGE_MAP section in you .CPP file add the line

<pre>ON_WM_WINDOWPOSCHANGING()</pre>

3. Then do the following

<pre>

void CMyTestDlg:: OnWindowPosChanging(WINDOWPOS* lpwndPos)

{

	//Get Desktop Size

	CRect rectScreen;

	SystemParametersInfo(SPI_GETWORKAREA, 0, &rectScreen, 0);



	//Screen Offsets for Snap

	int m_nXOffset = 20;

	int m_nYOffset = 20;



	//Min & Max X Position

	if (lpwndPos->x < 0)

  lpwndPos->x = 0;

	else if (lpwndPos->x + lpwndPos->cx > rectScreen.right)

  lpwndPos->x = rectScreen.right - lpwndPos->cx;



	//Min & Max Y Position

	if (lpwndPos->y < 0)

  lpwndPos->y = 0;

	else if (lpwndPos->y + lpwndPos->cy > rectScreen.bottom)

  lpwndPos->y = rectScreen.bottom - lpwndPos->cy;



	int nGapX = 0;



	//X Snap

	if (abs(lpwndPos->x - rectScreen.left) <= m_nXOffset)

	{

  nGapX = lpwndPos->x - rectScreen.left;

  lpwndPos->cx+= nGapX;

  lpwndPos->x = rectScreen.left;

	}

	else if (abs(lpwndPos->x + lpwndPos->cx - rectScreen.right) <= m_nXOffset)

	{

  nGapX = rectScreen.right - (lpwndPos->x + lpwndPos->cx);

  lpwndPos->cx+= nGapX;

  lpwndPos->x = rectScreen.right - lpwndPos->cx;

	}



	//Y Snap

	if (abs(lpwndPos->y - rectScreen.top) <= m_nYOffset)

  lpwndPos->y = rectScreen.top;

	else if (abs(lpwndPos->y + lpwndPos->cy - rectScreen.bottom) <= m_nYOffset)

  lpwndPos->y = rectScreen.bottom - lpwndPos->cy;

}

</pre>

[freestyle]

PS:

This will Dock/Snap the current window to the edges of the screen, not to another dialog.

[y_notm]

OK, the code runs fine, no errors, but the program won't dock.

am I missing something? I added in all the coding you posted.

[freestyle]

Ok I copied the above code into a new project, and it worked OK. I have put a link to the zip file onto my site: Test Project.

One thing I did notice, was when the dialog gets too close to the left or right side of the screen, the dialog increases in size (this was needed for the client, but I forgot to remove it here).

The code should be as follows:

<pre>

	//X Snap

	if (abs(lpwndPos->x - rectScreen.left) <= m_nXOffset)

	{

//  nGapX = lpwndPos->x - rectScreen.left;

//  lpwndPos->cx+= nGapX;

  lpwndPos->x = rectScreen.left;

	}

	else if (abs(lpwndPos->x + lpwndPos->cx - rectScreen.right) <= m_nXOffset)

	{

//  nGapX = rectScreen.right - (lpwndPos->x + lpwndPos->cx);

//  lpwndPos->cx+= nGapX;

  lpwndPos->x = rectScreen.right - lpwndPos->cx;

	}

</pre>

If it still does not work, or if you have any other questions drop me an email, or PM.

[freestyle]

For the same project done in Visual C++ .NET (MFC) incase there is a difference: Test Project 2

[y_notm]

got it! i had the ON_WM_WINDOWPOSCHANGING() in the wrong message map. thanks for the help!