VC: add images

Overall: for common BMP \ DIB format images, The LoadImage () function is provided in GDI; the OleLoadPicture () function is provided for files in formats such as PNP, JPG, GIF, and VC ++.

I,

1. Create a single-document application and add functions and variables to the View class as follows:

Void LoadPicture ();

LPPICTURE m_picture;

Float size;

CString filename;

2. LoadPicture (); the function code is as follows:

Void CTestView: LoadPicture ()

// LPPICTRUE LoadPicture (CStirng filename)

{

HANDLE hfile = CreateFile (filename, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL );

_ ASSERTE (INVALID_HANDLE_VALUE! = Hfile );

DWORD dfilesize = GetFileSize (hfile, NULL );

_ ASSERTE (-1! = Dfilesize );

LPVOID p = NULL;

HGLOBAL h = GlobalAlloc (GMEM_MOVEABLE, dfilesize );

 

_ ASSERTE (NULL! = H );

P = GlobalLock (h );

 

_ ASSERTE (NULL! = P );

DWORD dw = 0;

BOOL bread = ReadFile (hfile, p, dfilesize, & dw, NULL );

_ ASSERTE (FALSE! = Bread );

GlobalUnlock (h );

CloseHandle (hfile );

LPSTREAM pstm = NULL;

HRESULT hr = CreateStreamOnHGlobal (h, TRUE, & pstm );

_ ASSERTE (SUCCEEDED (hr) & pstm );

If (m_picture)

M_picture-> Release ();

Hr =: OleLoadPicture (pstm, dfilesize, FALSE, IID_IPicture, (LPVOID *) & m_picture );

_ ASSERTE (SUCCEEDED (hr) & m_picture );

Pstm-> Release ();

// Return m_picture;

}

3. Add two buttons in the toolbar to expand and zoom out. In the View class, add a file to open:

Void CTestView: OnFileOpen ()

{

// TODO: Add your command handler code here

Static char sfile [] = "JPEG (*. JPEG ;*. JPE ;*. JIF ;*. JPG) | *. JPEG ;*. JPE ;*. JIF ;*. JPG | BMP Windows Bitmap (*. BMP ;*. DIB ;*. RLE) | *. BMP ;*. DIB ;*. RLE | PNG (*. PNG) | *. PNG | ";

CFileDialog dlg (TRUE, "jpg", "", OFN_ALLOWMULTISELECT, sfile );

If (IDOK = dlg. DoModal ())

{

Filename = dlg. GetPathName ();

LoadPicture ();

}

Invalidate ();

}

 

Void CTestView: OnBig ()

{

// TODO: Add your command handler code here

Size = size * 0.909;

Invalidate ();

}

 

Void CTestView: OnSmall ()

{

// TODO: Add your command handler code here

Size = size * 1.1;

Invalidate ();

}

4. Compile the OnDraw function code:

Void CTestView: OnDraw (CDC * pDC)

{

CTestDoc * pDoc = GetDocument ();

ASSERT_VALID (pDoc );

// TODO: add draw code for native data here

If (m_picture)

{

Long width;

Long height;

M_picture-> get_Width (& width );

M_picture-> get_Height (& height );

Int nwidth = MulDiv (width, GetDeviceCaps (pDC-> GetSafeHdc (), LOGPIXELSX ),

2540 );

Int nheight = MulDiv (height, GetDeviceCaps (pDC-> GetSafeHdc (), LOGPIXELSY ),

2540 );

CRect rc;

GetClientRect (& rc );

M_picture-> Render (pDC-> GetSafeHdc (), (rc. Width ()-nwidth/size)/2, (rc. Height ()-nheight/size)/2,

Nwidth/size, nheight/size, 0, height, width,-height, & rc );

}

 

}

II,

1. Add bitmap Resources

2. functions:

 

Void CTestDlg: OnPaint ()

{

If (IsIconic ())

{

CPaintDC dc (this); // device context for painting

 

SendMessage (WM_ICONERASEBKGND, (WPARAM) dc. GetSafeHdc (), 0 );

 

// Center icon in client rectangle

Int cxIcon = GetSystemMetrics (SM_CXICON );

Int cyIcon = GetSystemMetrics (SM_CYICON );

CRect rect;

GetClientRect (& rect );

Int x = (rect. Width ()-cxIcon + 1)/2;

Int y = (rect. Height ()-cyIcon + 1)/2;

 

// Draw the icon

Dc. DrawIcon (x, y, m_hIcon );

}

Else

{

CPaintDC dc (this );

CRect rect;

GetClientRect (& rect); // obtain the size of the form.

CDC dcMem;

DcMem. CreateCompatibleDC (& dc );

CBitmap BMP background;

BMP background. LoadBitmap (IDB_BITMAP1); // load the background image

BITMAP bitMap;

BMP background. GetBitmap (& bitMap );

CBitmap * pbmpOld = dcMem. SelectObject (& BMP background );

Dc. StretchBlt (, rect. Width (), rect. Height (), & dcMem, bitMap. bmWidth, bitMap. bmHeight, SRCCOPY); // draw a form

// CDialog: OnPaint ();

}

}

III,

1. Bitmap:

CPaintDC dc (this );

CRect rect;

GetClientRect (& rect); // obtain the size of the form.

CDC dcMem;

DcMem. CreateCompatibleDC (& dc );

CBitmap BMP background;

BMP background. LoadBitmap (IDB_BITMAP1); // load the background image

BITMAP bitMap;

BMP background. GetBitmap (& bitMap );

CBitmap * pbmpOld = dcMem. SelectObject (& BMP background );

 

 

Long width;

Width = bitmap. bmWidth;

// M_picture-> get_Width (& width );

Long height;

Height; = bitmap. bmHeight;

// M_picture-> get_Height (& height );

COLORREF color1, color2;

For (long I = 0; I

{

For (long j = 0; j <width; j ++)

{

Color1 = dcMem. GetPixel (j, I );

Color2 = dcMem. GetPixel (width-j, height-I );

DcMem. SetPixel (j, I, color2 );

DcMem. SetPixel (width-j, height-I, color1 );

}

}*/

 

Dc. StretchBlt (, rect. Width (), rect. Height (), & dcMem, bitMap. bmWidth, bitMap. bmHeight, SRCCOPY); // draw a form

 

2. Images:

/* CPaintDC (this );

CDC dcMem;

DcMem. CreateCompatibleDC (& dc );

Long width;

M_picture-> get_Width (& width );

Long height;

M_picture-> get_Height (& height );

COLORREF color1, color2;

For (long I = 0; I

{

For (long j = 0; j <width; j ++)

{

Color1 = dcMem. GetPixel (j, I );

Color2 = dcMem. GetPixel (width-j, height-I );

DcMem. SetPixel (j, I, color2 );

DcMem. SetPixel (width-j, height-I, color1 );

}

}*/