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dev_clear_windowdev_clear_windowDevClearWindowDevClearWindow (Operator)


dev_clear_windowdev_clear_windowDevClearWindowDevClearWindow — Clear the contents of the active graphics window.


dev_clear_window( : : : )

Herror dev_clear_window()

Herror T_dev_clear_window()

void DevClearWindow()

static void HWindow::DevClearWindow()

static void HOperatorSet.DevClearWindow()

static void HWindow.DevClearWindow()


dev_clear_windowdev_clear_windowDevClearWindowDevClearWindowDevClearWindow clears the contents of the active graphics window including the history of the displayed iconic objects. The output parameters that have been set for this window via the context menu, the visualization parameters dialog, or the appropriate operators (e.g., with dev_set_colordev_set_colorDevSetColorDevSetColorDevSetColor, dev_set_drawdev_set_drawDevSetDrawDevSetDrawDevSetDraw, etc.) remain unmodified.

The operator is equivalent to pressing the Clear button of the active graphics window.

A graphics window can be activated by calling dev_set_windowdev_set_windowDevSetWindowDevSetWindowDevSetWindow or by pressing the Activate button in the tool bar of the selected graphics window.


Using the code export feature of HDevelop, the code that is generated for this operator may have a different behavior than the related HALCON operator. For a detailed description of the code export of HDevelop graphics operators into the different programming languages see in the “HDevelop User's Guide” the chapter Code Export -> General Aspects of Code Generation -> Graphics Windows.

Example (HDevelop)

read_image (Image, 'fabrik')
regiongrowing (Image, Regions, 3, 3, 6, 100)
Number := |Regions|
dev_update_window ('off')
for i := 1 to Number by 1
  select_obj (Regions, RegionSelected, i)
  dev_clear_window ()
  dev_display (RegionSelected)
  * stop ()


dev_clear_windowdev_clear_windowDevClearWindowDevClearWindowDevClearWindow returns always 2 (H_MSG_TRUE).

Possible Predecessors

dev_set_windowdev_set_windowDevSetWindowDevSetWindowDevSetWindow, dev_open_windowdev_open_windowDevOpenWindowDevOpenWindowDevOpenWindow, dev_displaydev_displayDevDisplayDevDisplayDevDisplay

Possible Successors


See also