C / C++ / MFC

1-Jun-07 9:01

I "think" you may be able to use a 32-bit ARGB DIBsection - I put together this test just to
make sure the alpha channel stuff was working.

(My "hdc" would be your "dcMem" and you wouldn't want to delete it or un-select your alpha bitmap
like I have if you pass it to UpdateLayeredWindow())

Image TransparentSrcBitmap(L"clockbg.bmp");
 
LONG lImageWidth = TransparentSrcBitmap.GetWidth();
LONG lImageHeight = TransparentSrcBitmap.GetHeight();
WORD wBitsPerPixel = 32;
 
//LONG lBytesPerRow = (((lImageWidth * (long)wBitsPerPixel + 31L) & (~31L)) / 8L);
LONG lBytesPerRow = lImageWidth * 4;
 
BITMAPINFO bmi;
memset(&bmi, 0, sizeof(BITMAPINFO));
bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmi.bmiHeader.biWidth = lImageWidth;
bmi.bmiHeader.biHeight = lImageHeight;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = wBitsPerPixel;
bmi.bmiHeader.biCompression = BI_RGB;
bmi.bmiHeader.biSizeImage = lBytesPerRow * lImageHeight;
//bmi.bmiHeader.biXPelsPerMeter = 0;
//bmi.bmiHeader.biYPelsPerMeter = 0;
//bmi.bmiHeader.biClrUsed = 0;
//bmi.bmiHeader.biClrImportant = 0;
 
HDC hdc = ::CreateCompatibleDC(0);
 
BYTE* pBitmapBits;
HBITMAP hBitmap = ::CreateDIBSection(hdc, &bmi, DIB_RGB_COLORS, (void**)&pBitmapBits, NULL, 0);
 
if (hBitmap)
{   
   memset(pBitmapBits, 0, bmi.bmiHeader.biSizeImage);
 
   HGDIOBJ hOldBitmap = ::SelectObject(hdc, hBitmap);
 
   Graphics DstGraphics(hdc);
   DstGraphics.DrawImage(&TransparentSrcBitmap, 0, 0, TransparentSrcBitmap.GetWidth(), TransparentSrcBitmap.GetHeight());
 
   //** Test - blt the memory dc to the screen to make sure alpha channel data carried over
   BLENDFUNCTION bf;
   bf.BlendOp = AC_SRC_OVER;
   bf.BlendFlags = 0;
   bf.SourceConstantAlpha = 0x7F; // Alpha multiplier applied overall - use 0xFF - 0x7F is a test
   bf.AlphaFormat = AC_SRC_ALPHA;
 
   HDC hClientDC = ::GetDC(*this);
   ::AlphaBlend(hClientDC, 50, 50, TransparentSrcBitmap.GetWidth(), TransparentSrcBitmap.GetHeight(),
                hdc, 0, 0, TransparentSrcBitmap.GetWidth(), TransparentSrcBitmap.GetHeight(), bf);
   ::ReleaseDC(*this, hClientDC);
   //** End Test 
 
   ::SelectObject(hdc, hOldBitmap);<code> //<-- Don't do this when using with UpdateLayeredWindow()</code>
 
   ::DeleteObject(hBitmap);<code> //<-- Don't do this when using with UpdateLayeredWindow()</code>
}
 
::DeleteDC(hdc); <code>//<-- Don't do this when using with UpdateLayeredWindow()</code>

Sorry about all the strange extra variables - I cut and paste from assorted working code to throw
together a test - saves some typing. Smile | :)

-- modified at 15:30 Friday 1st June, 2007

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Adno1-Jun-07 10:39

1-Jun-07 10:39

thank you Mark very much for taking the time, it mean as lot me.
but is not quite there is coming out pixalated, the alpha value is being replace by a black colour.
program running image:
http://img118.imageshack.us/img118/8953/testwindowhu9.png
.
.
.

Code: the main method.
http://rafb.net/p/1Dfouz58.html

thank you so much .... Big Grin | :-D

Mark Salsbery1-Jun-07 10:48

1-Jun-07 10:48

No problem!

Can you show your latest code?

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Mark Salsbery1-Jun-07 10:50

1-Jun-07 10:50

~~What's "image" and what's "program window" in your screenshot?~~

Never mind I get it LOL

I'd still like to see your updated code if you can Smile | :)

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Adno1-Jun-07 10:52

1-Jun-07 10:52

Code: the main method.

http://rafb.net/p/1Dfouz58.html

^i posted here

Mark Salsbery1-Jun-07 11:06

1-Jun-07 11:06

Try replacing

int t = UpdateLayeredWindow(hwnd, NULL, NULL, &sz, hdc, &ptSrc, NULL, &bf, ULW_COLORKEY );

with

int t = UpdateLayeredWindow(hwnd, NULL, NULL, &sz, hdc, &ptSrc, NULL, &bf, ULW_ALPHA );

You probably want to set bf.SourceConstantAlpha = 0xFF; (instead of 0x7F) too.

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Mark Salsbery1-Jun-07 11:10

1-Jun-07 11:10

And comment out these lines - they were there for testing only (leave in the BLENDFUNCTION
since you're using that)...

// comment these out
HDC hClientDC = ::GetDC(hwnd);
::AlphaBlend(hClientDC, 50, 50, TransparentSrcBitmap.GetWidth(), TransparentSrcBitmap.GetHeight(),
hdc, 0, 0, TransparentSrcBitmap.GetWidth(), TransparentSrcBitmap.GetHeight(), bf);
::ReleaseDC(hwnd, hClientDC);

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Adno1-Jun-07 11:23

1-Jun-07 11:23

thanks a million

one more thing since i've got you here.
will i be able to draw on this window?
i.e:
Graphics graphics(GetDC(hwnd));
Bitmap bitmap(L"clockbg.bmp");
graphics.DrawImage(&bitmap, 100,100);

i did a quick test it dont seem to be working.

my goal would be to be as great as you one day lol

Mark Salsbery1-Jun-07 11:33

1-Jun-07 11:33

Lamefif wrote:
will i be able to draw on this window?

Absolutely not!

Just kidding.

The DIBSection bitmap is already in a DC which is associated with a Graphics object (DstGraphics).
That's where you should draw. Example...

// redraw the image background
DstGraphics.DrawImage(&TransparentSrcBitmap, 0, 0, TransparentSrcBitmap.GetWidth(), TransparentSrcBitmap.GetHeight());
 
// draw some stuff on top of the background
Bitmap bitmap(L"clockbg.bmp");
DstGraphics.DrawImage(&bitmap, 100,100);

You have full access to the bitmap that IS your window. You can write directly to the pixel
bytes, use GDI+ to draw, use GDI to draw, or any combination of those Smile | :)

You may need to call UpdateLayeredWindow() again to see changes (i think the hdcSrc param can be
NULL for updates).

Mark

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

Adno1-Jun-07 11:55

1-Jun-07 11:55

Cheers Mark man

i new i could do it. :->

Mark Salsbery1-Jun-07 12:02

1-Jun-07 12:02

"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder

How to get GUID

john56321-Jun-07 3:31

john5632

1-Jun-07 3:31

Hi Experts,

I want to create instance of a inteface(IPropertyBag) ,defind in a abc.dll file.
And same name interface exist in ocidl.h file.How can i pass a correct GUID
so that i can access method defind in abc.dll.

i try like this

IPropertyBag* Properties;
hr=CoCreateInstance(__uuidof(PropertyBag),NULL,CLSCTX_INPROC_SERVER,
__uuidof(IPropertyBag),(void**) &Properties);

Roger Stoltz1-Jun-07 4:13

Roger Stoltz

1-Jun-07 4:13

pther wrote:
I want to create instance of a inteface(IPropertyBag) ,defind in a abc.dll file.

You don't "create" interfaces.
You create a component and ask for one, or several, of its interfaces.

When you create a component you have to specify which component you want to create and which interface you want to access in that component.
This is what the arguments to ::CoCreateInstance() is for.
The first parameter should be the CLSID of the component you want to create, have a look here[^].

"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown

CPallini1-Jun-07 5:44

CPallini

1-Jun-07 5:44

You can use the Visual Studio Ole View tool to see the CLSID of the object.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

john56321-Jun-07 21:15

john5632

1-Jun-07 21:15

I saw the CLSID by ole Tool as u suggested.And i try to put the CLSID directly in CoCreateInstance().
Like:
hr=::CoCreateInstance(uuid(47000673-7DB2-44C9-8AC1-65266117D280),NULL,CLSCTX_INPROC_SERVER,
__uuidof(IPropertyBag),(void**) &Properties);

But it dispaly syntext error.

error C2059: syntax error : ')'
error C2059: syntax error : 'bad suffix on number'
error C2059: syntax error : 'bad suffix on number'
error C2059: syntax error : 'bad suffix on number'

How can i make it correct