C / C++ / MFC

1. Get the area of the main dialog that you want to obscure - this is most likely to be in client co-ordinates
2. Convert to screen co-ordinates using CWnd::ClientToScreen[^]
3. Now ensure that the child dialog covers that (screen co-ordinate) area. If you use MoveWindow, the screen co-ordinates are what you want to position the dialog

Neil Urquhart wrote:

I am terribly confused about how to move CWnd objects around. With screen coords, client coords, dialog units, screen units, AaaRGh.

pashamsridhar wrote:

Hi i am new to vc++6.0 and i want to get menu item text which clicked by user.

Copies the label of the specified menu item to the specified buffer.

 
int GetMenuString(
   UINT nIDItem,
   LPTSTR lpString,
   int nMaxCount,
   UINT nFlags 
) const;
int GetMenuString(
   UINT nIDItem,
   CString& rString,
   UINT nFlags 
) const;

<code>
	HDC pDC=::GetDC(0);
HDC TmpDC=CreateCompatibleDC(pDC);
CImage _image;
_image.Load(_T("//read.tif"));
int width=_image.GetWidth();
int height=_image.GetHeight();
HGDIOBJ TmpObj2 = SelectObject(TmpDC,(HGDIOBJ)(HBITMAP)_image);			
Rectangle(TmpDC, 0,0, width/2, height/2 );
SelectObject(TmpDC,TmpObj2);
_image.Save( _T("D:\\newy.jpg"), Gdiplus::ImageFormatBMP);
::ReleaseDC(NULL,pDC);

</code>

HDC pDC=::GetDC(0);
HDC TmpDC=CreateCompatibleDC(pDC);
CImage _image;
_image.Load(_T("//read.tif"));
int width=_image.GetWidth();
int height=_image.GetHeight();
HGDIOBJ TmpObj2 = SelectObject(TmpDC,(HGDIOBJ)(HBITMAP)_image);			

int newWidth  = width/2;
int newHeight = height/2;
HDC NewDC = CreateCompatibleDC(TmpDC);
HBITMAP NewBitmap = CreateCompatibleBitmap(TmpDC, newWidth, newHeight);
HGDIOBJ NewTmpObj = SelectObject(NewDC, NewBitmap);

BitBlt(NewDC, 0, 0, newWidth, newHeight, TmpDC, 0, 0, SRCCOPY);

SelectObject(NewDC, NewTmpObj);
DeleteDC(NewDC);

SelectObject(TmpDC,TmpObj2);
::ReleaseDC(NULL,pDC);

CImage newImage;
newImage.Attach(NewBitmap);
newImage.Save( _T("D:\\newy.jpg"), Gdiplus::ImageFormatJPEG);
DeleteObject(NewBitmap); //Is this needed, will CImage destroy the bitmap or not?

// First load the original image
CImage imageOriginal;
imageOriginal.Load(_T("Here is the path to your original image"));

// Make a copy of the original image
CImage imageNew;
imageNew.Create(imageOriginal.GetWidth(), imageOriginal.GetHeight(), imageOriginal.GetBPP());
imageOriginal.BitBlt(imageNew.GetDC(), CPoint(0,0));
imageNew.ReleaseDC();

// Now imageNew holds the copy of original image
....

// First load the original image
CImage imageOriginal;
imageOriginal.Load(_T("Here is the path to your original image"));

// Here is the rect that we will copy from the original image (in this case 1/4 of it)
CRect rectCopy(0, 0, imageOriginal.GetWidth() / 2, imageOriginal.GetHeight() / 2);
	
// Make a copy of the specific part
CImage imageNew;
imageNew.Create(rectCopy.Width(), rectCopy.Height(), imageOriginal.GetBPP());
imageOriginal.BitBlt(imageNew.GetDC(), rectCopy, rectCopy.TopLeft());
imageNew.ReleaseDC();

// Now imageNew holds the copy of the specific part from original image

CImage imageOriginal;
imageOriginal.Load(_T( "read.tif" ));

// Here is the rect that we will copy from the original image (in this case 1/4 of it)
//CRect rectCopy(0, 0, imageOriginal.GetWidth() / 2, imageOriginal.GetHeight() / 2);

<code>CRect rectCopy(9177,68, 10566, 635);</code>

// Make a copy of the specific part
CImage imageNew;
imageNew.Create(rectCopy.Width(), rectCopy.Height(), imageOriginal.GetBPP());
imageOriginal.BitBlt(imageNew.GetDC(), rectCopy, rectCopy.TopLeft());
imageNew.Save(_T("D://imgnew.jpg"));

imageNew.ReleaseDC();

rajugis wrote:

when i gave this rect portion ..the saving images contains ..full black

// Check for color table after the creation of the new image
if(imageOriginal.IsIndexed())
{
	// If there is a color table for the original image
	// copy this table for the new image too.
	const int nMaxColors = imageOriginal.GetMaxColorTableEntries();
	RGBQUAD* pColorTable = new RGBQUAD[nMaxColors];
	imageOriginal.GetColorTable(0, nMaxColors, pColorTable);
	imageNew.SetColorTable(0, nMaxColors, pColorTable);
	delete [] pColorTable;
}

void CTestCImageAppDlg::OnBnClickedButtonTest()
{
	// First load the original image
	CImage imageOriginal;
	HRESULT hrLoad = imageOriginal.Load(_T("D:\\testImg1.tif"));
	if(FAILED(hrLoad))
	{
		CString msg;
		msg.Format(_T("Error on load. Code:%08x"), hrLoad);
		AfxMessageBox(msg);
		return;
	}
	
	// Here is the rect that we will copy from the original image (in this case 1/4 of it)
	CRect rectCopy(0, 0, imageOriginal.GetWidth() / 2, imageOriginal.GetHeight() / 2);

	// Create the new image
	CImage imageNew;
	imageNew.Create(rectCopy.Width(), rectCopy.Height(), imageOriginal.GetBPP());
	
	// Check the original image for color table 
        // after the creation of the new image
	if(imageOriginal.IsIndexed())
	{
		// If there is a color table for the original image
		// copy this table for the new image too.
		const int nMaxColors = imageOriginal.GetMaxColorTableEntries();
		RGBQUAD* pColorTable = new RGBQUAD[nMaxColors];
		imageOriginal.GetColorTable(0, nMaxColors, pColorTable);
		imageNew.SetColorTable(0, nMaxColors, pColorTable);
		delete [] pColorTable;
	}

        CRect rect(rectCopy);
        rect.OffsetRect(-rectCopy.left, -rectCopy.top);
	
        // Now we can blit the original image on the new image
	imageOriginal.BitBlt(imageNew.GetDC(), rect, rectCopy.TopLeft());

	// It is good to release the DC first
	imageNew.ReleaseDC();


	// Lets save the new image
	HRESULT hrSave = imageNew.Save(_T("D:\\testImg2.tif"), Gdiplus::ImageFormatTIFF);
	if(FAILED(hrSave))
	{
		CString msg;
		msg.Format(_T("Error on save. Code:%08x"),hrSave);
		AfxMessageBox(msg);
		return;
	}
}