LEADCAPTUREOPTION

typedef struct tagLEADCAPTUREOPTION 
{ 
   L_UINT uStructSize; 
   HCURSOR hCursor; 
   HCURSOR hStatusCursor; 
   L_INT nHotKey; 
   L_UINT uHotKeyModifiers; 
   L_INT nCancelKey; 
   L_INT nDelay; 
   L_UINT uCount; 
   L_INT nInterval; 
   L_UINT32 uFlags; 
} LEADCAPTUREOPTION, * pLEADCAPTUREOPTION; 

This structure is used in L_SetCaptureOptions and L_GetCaptureOption to set/get the capture options.

Member Description
uStructSize Size of this structure in bytes, for versioning. Use the sizeof() macro to calculate this value.
hCursor Cursor to place on image after capture. Default is NULL.
hStatusCursor Cursor to display as status between multiple captures. Default is NULL.
nHotKey Key code for activation key. Keys should be a keyboard keys. The default hot key is F11.

The user can immediately capture by setting the hot key to zero (0).

uHotKeyModifiers Modifier keys used with nHotKey. Default is 0. Possible values are listed below and may be combined:
  MOD_ALT Alt Key pressed.
  MOD_CONTROL Control key pressed.
  MOD_SHIFT Shift key pressed.
  0 No modifier key was pressed.
nCancelKey Key code for capture operation cancel key. Default is ESC. You cannot set this to the 'ALT' key (VK-MENU). If you do, it will be ignored internally and set to 'ESC' (VK-ESCAPE).
nDelay Milliseconds delay before capture. Default is 0
uCount Number of times to capture. 0 or 1 means one capture, 2 means 2 captures, etc. Default is 1.
nInterval Milliseconds delay between captures. Default is 0.
uFlags Flag that indicates whether to optimize hotkey processing. Possible values are:
  Value Meaning
  0 [0x0000] Perform normal hot key processing.
  CAPTURE_OPTIMIZED_HOTKEY [0x0001] Use a global system hook for hotkey processing.

Comments

Normally, when a capture function is called, the function enters a loop, and waits for the hot key specified in nHotKey to be pressed, before capturing. This loop can cause the CPU usage indicator to appear maxed out. Specifying CAPTURE_OPTIMIZED_HOTKEY in uFlags will cause the capture function to return immediately, if a hotkey has been specified in nHotKey. In this case, a global system hotkey hook is established and used to wait for the hotkey to be pressed. When the hotkey is pressed, the capture is performed and the callback passed to the capture function is called with the result of the capture. Use this option only if the normal behavior is causing your application problems. This option is ignored in Win95/98/Me.

Help Version 19.0.2017.10.18
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