Problem with drawing using GDI functions...
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I've created an application that paints on the window using GDI functions. It works fine. But because it is still under development it sometimes craches. It seems that if there are certain craches Windows Vista suddenly decides to treat my application in a new way: while drawing on the window it decides it must redraw that was on the screen when i started my application. The effect is that some drawing is lost. Windows continues with this behavour till i reboot my pc. After i booted the same piece of code draws the window correctly. I used Spy++ to find out what's happening. When the window is correctly displayed i see the following:
<00037> 00340626 P WM_LBUTTONDOWN fwKeys:MK_LBUTTON xPos:1215 yPos:640
<00038> 00340626 P WM_LBUTTONUP fwKeys:0000 xPos:1215 yPos:640
<00039> 00340626 P WM_LBUTTONDOWN fwKeys:MK_LBUTTON xPos:1249 yPos:711
<00040> 00340626 P WM_LBUTTONUP fwKeys:0000 xPos:1249 yPos:711(I press the mousebutton to start drawing, it draws the window, i press the mousebutton again to close the window)
When things go wrong Spy++ reports the following:
<00037> 00340626 P WM_LBUTTONDOWN fwKeys:MK_LBUTTON xPos:1219 yPos:643
<00038> 00340626 P WM_LBUTTONUP fwKeys:0000 xPos:1219 yPos:643
<00039> 004904B2 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00040> 004904B2 R WM_WINDOWPOSCHANGING
<00041> 004F0646 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00042> 004F0646 R WM_WINDOWPOSCHANGING
<00043> 00340626 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00044> 00340626 R WM_WINDOWPOSCHANGING
<00045> 004904B2 S WM_WINDOWPOSCHANGED lpwp:0012FE20
<00046> 004904B2 R WM_WINDOWPOSCHANGED
<00047> 004F0646 S WM_WINDOWPOSCHANGED lpwp:0012FE20
<00048> 004F0646 R WM_WINDOWPOSCHANGED
<00049> 00340626 S WM_WINDOWPOSCHANGED lpwp:0012FE20
<00050> 00340626 S .WM_SIZE fwSizeType:SIZE_RESTORED nWidth:1280 nHeight:770
<00051> 00340626 R .WM_SIZE
<00052> 00340626 R WM_WINDOWPOSCHANGED
<00053> 004904B2 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00054> 004904B2 R WM_WINDOWPOSCHANGING
<00055> 004F0646 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00056> 004F0646 R WM_WINDOWPOSCHANGING
<00057> 00340626 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00058> 00340626 R WM_WINDOWPOSCHANGING
<00059> 00340626 P WM_PAINT hdc:00000000
<00060> 00340626 S WM_ERASEBKGND hdc:D1011D9A
<00061> 00340626 R WM_ERASEBKGND fErased:False
<00062> 00340626 S WM_GETICO -
I've created an application that paints on the window using GDI functions. It works fine. But because it is still under development it sometimes craches. It seems that if there are certain craches Windows Vista suddenly decides to treat my application in a new way: while drawing on the window it decides it must redraw that was on the screen when i started my application. The effect is that some drawing is lost. Windows continues with this behavour till i reboot my pc. After i booted the same piece of code draws the window correctly. I used Spy++ to find out what's happening. When the window is correctly displayed i see the following:
<00037> 00340626 P WM_LBUTTONDOWN fwKeys:MK_LBUTTON xPos:1215 yPos:640
<00038> 00340626 P WM_LBUTTONUP fwKeys:0000 xPos:1215 yPos:640
<00039> 00340626 P WM_LBUTTONDOWN fwKeys:MK_LBUTTON xPos:1249 yPos:711
<00040> 00340626 P WM_LBUTTONUP fwKeys:0000 xPos:1249 yPos:711(I press the mousebutton to start drawing, it draws the window, i press the mousebutton again to close the window)
When things go wrong Spy++ reports the following:
<00037> 00340626 P WM_LBUTTONDOWN fwKeys:MK_LBUTTON xPos:1219 yPos:643
<00038> 00340626 P WM_LBUTTONUP fwKeys:0000 xPos:1219 yPos:643
<00039> 004904B2 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00040> 004904B2 R WM_WINDOWPOSCHANGING
<00041> 004F0646 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00042> 004F0646 R WM_WINDOWPOSCHANGING
<00043> 00340626 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00044> 00340626 R WM_WINDOWPOSCHANGING
<00045> 004904B2 S WM_WINDOWPOSCHANGED lpwp:0012FE20
<00046> 004904B2 R WM_WINDOWPOSCHANGED
<00047> 004F0646 S WM_WINDOWPOSCHANGED lpwp:0012FE20
<00048> 004F0646 R WM_WINDOWPOSCHANGED
<00049> 00340626 S WM_WINDOWPOSCHANGED lpwp:0012FE20
<00050> 00340626 S .WM_SIZE fwSizeType:SIZE_RESTORED nWidth:1280 nHeight:770
<00051> 00340626 R .WM_SIZE
<00052> 00340626 R WM_WINDOWPOSCHANGED
<00053> 004904B2 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00054> 004904B2 R WM_WINDOWPOSCHANGING
<00055> 004F0646 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00056> 004F0646 R WM_WINDOWPOSCHANGING
<00057> 00340626 S WM_WINDOWPOSCHANGING lpwp:0012FE20
<00058> 00340626 R WM_WINDOWPOSCHANGING
<00059> 00340626 P WM_PAINT hdc:00000000
<00060> 00340626 S WM_ERASEBKGND hdc:D1011D9A
<00061> 00340626 R WM_ERASEBKGND fErased:False
<00062> 00340626 S WM_GETICOThat just looks like the window position is getting changed. Hard to say what may be wrong from just looking at the messages that Windows is sending your applications window. You probably need to post some of the applicable code.