I want to display information somewhere on the desktop for say, 15
seconds, and then have it disappear.
What I do now is spawn a thread that calls CreateDC for DISPLAY, draws
stuff, then sleeps for 15 seconds and calls DestroyDC when it is
needed.
However, after DeleteDC the image I have shown on the screen is still
there.
What do I do to wipe the image?

Sergei Shelukhin wrote:
Create a window and draw in it when it receives a WM_PAINT message.
Destroy the window after 15 seconds.

--
Norm

To reply, change domain to an adult feline.

Hmm... You mean drawing opaque stuff on a transparent layered window?

On 5 avr, 23:21, Sergei Shelukhin <realg...@gmail.com> wrote:
If you want to make a Splash Screen, KB230090 or KB186459

On Apr 7, 2:21 am, Christian ASTOR <casto...@club-internet.fr> wrote:
What I actually want to do is output some text to my desktop.
I am trying to use the following code, but to no avail. if I replace
drawing and UpdateLayeredWindow in this code with
SetLayeredWindowAttributes w/some opacity, I do get a semi-transparent
empty window at appropriate place, so I guess there are no problems
with window itself.

Also, none of the functions set last error, and setting the font/text
color (just in case) doesn't help either.

HWND textHWND = CreateWindowEx(WS_EX_LAYERED | WS_EX_TRANSPARENT |
WS_EX_TOPMOST | WS_EX_TOOLWINDOW, L"DWMHelper", NULL, WS_POPUP, left,
top, right - left, bottom - top, hWnd, NULL, hInst, NULL);
ShowWindow(textHWND, SW_SHOW); // moving this anywhere or adding
UpdateWindow doesn't help either

HDC hdc = GetDC(textHWND);
HDC sourceHdc = CreateCompatibleDC(hdc);

TextOut(sourceHdc, 0, 0, L"Hello world!", 12);

POINT zz;
zz.x = zz.y = 0;

BLENDFUNCTION bf;
bf.BlendOp = AC_SRC_OVER;
bf.BlendFlags = 0;
bf.AlphaFormat = 0;
bf.SourceConstantAlpha = 255;

UpdateLayeredWindow(textHWND, NULL, NULL, NULL, sourceHdc, &zz, 1,
&bf, ULW_OPAQUE);

//tried update/show whatever here

On 8 avr, 10:06, Sergei Shelukhin <realg...@gmail.com> wrote:

It's normal : a bitmap must be selected in sourceHdc and psize must be
set correctly...

On Apr 8, 6:03 am, Christian ASTOR <casto...@club-internet.fr> wrote:
Thanks, made it work