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POPreserve painted client area between calls to WM_PAINT in win32
 

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    <p>I am trying to paint(draw) text on the client area on a window in response to some event(not in the <code>WM_PAINT</code> message), so how can I preserve the state of the client area between calls to <code>WM_PAINT</code>? I understand that every time there is a <code>WM_PAINT</code> message(or window refreshes) the window gets redrawn and everything out side <code>WM_PAINT</code> doesn't matter anymore. I think I will be able to communicate better with code, so here is what I have now.</p> <pre><code>HDC mdc; int WINAPI WinMain (HINSTANCE hThisInstance, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nFunsterStil) { LoadBitmap(...); // for skinning the app. stuff.. } LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { case WM_PAINT: PAINTSTRUCT ps; HDC hdc = BeginPaint(hwnd, &amp;ps); BITMAP bm; HDC dcSkin = CreateCompatibleDC(hdc); GetObject(hSkinBmp, sizeof(bm), &amp;bm); SelectObject(dcSkin, hSkinBmp); BitBlt(dcSkin, 0, 0, wWidth, wHeight, mdc, 0, 0, SRCCOPY); BitBlt(hdc, 0, 0, wWidth, wHeight, dcSkin, 0, 0, SRCCOPY); DeleteDC(dcSkin); EndPaint(hwnd, &amp;ps); break; case WM_LBUTTONDOWN; HDC hdc = GetDC( hwnd ); mdc = CreateCompatibleDC( hdc ); LPRECT rect; GetClientRect( hwnd, rect); SelectObject( mdc, CreateCompatibleBitmap( hdc, rect-&gt;right, rect-&gt;bottom ) ); BitBlt( mdc,0,0,rect-&gt;right,rect-&gt;bottom,hdc,0,0,SRCCOPY ); HFONT hfont = CreateFont( 0, 0, 0, 0, FW_NORMAL, FALSE, FALSE, FALSE, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, PROOF_QUALITY, DEFAULT_PITCH | FF_SWISS , 0 ); HFONT hOldFont = (HFONT)SelectObject( mdc, hfont ); SetTextColor( mdc, RGB(255,0,0) ); SetBkColor( mdc, RGB(255,255,0) ); TextOut( mdc, 50, 150, logintext.c_str(), strlen( logintext.c_str() ) ); SelectObject( mdc, hOldFont ); ReleaseDC( hwnd, hdc); InvalidateRect( hwnd, 0, TRUE ); break; } </code></pre> <p>As you can see, I have to paint the client area of the window with a bmp, then when mouse button down message comes, I have to output some text on top of the skinned client area. What I am doing is saving the memory dc created in the <code>WM_LBUTTONDOWN</code> message and trying to paint the window dc first with the dc for skin then the dc for text(memory dc created in <code>WM_LBUTTONDOWN</code>).</p> <p>The skin bitmap show as it is supposed to, but the Text doesn't.</p> <p>How do I achieve this ?</p>
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    1. USStudentX
    1. USStudentX
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      1. VTUpMod
    1. COWhat you need to do is tell your `WM_PAINT` handler, "Hey, when you paint, could you also draw the login text? Thanks."
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      1. USRaymond Chen
 

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