Invalidate - forces the window to be redrawn as soon as possible (that is, marks the client part of the window as "invalid", as a result, the system, in the order of the queue, sends the window all the necessary messages to redraw its contents);

InvalidateEx - forces the window and all its child windows to be redrawn recursively;

InvalidateNC(recursive) - Marks as "invalid" the entire window along with the non-client part, and if the parameter recursive = true, then in this case the same is done recursively for all child windows;

Update - immediately refreshes the window (if required, the system sends it all the necessary messages);

BeginUpdate - increases the counter of "prohibitions" on updating the window, as a result the window will not redraw its contents until this counter is reset after the corresponding number of calls to the EndUpdate method;

EndUpdate - decreases the counter of "prohibitions" for redrawing. When this counter reaches 0, the window is redrawn if necessary;

 

DoubleBuffered- determines whether double buffering is used to draw the window (and all windows that are children of this object). Double buffering increases the speed at which the visual is redrawn. In KOL, almost any visual object (including a form) can use double buffering. Exception: rich edit;

DblBufTopParent - returns the parent visual with the top-level double buffering property;

Transparent - transparency of the background of the client part of the visual object. In KOL, a lot of visual elements (there are a few exceptions) can be "transparent". To implement transparency, double buffering is also used, i.e. all parents of transparent "controls" are automatically set to DoubleBuffered = true;

UpdateRgn - handle of the region to be redrawn. Set in the OnPaint event handler, can be used to restrict the redrawing area in order to optimize performance;

EraseBackground - a boolean flag for passing it to the GetUpdateRegion function, when the system asks for the window area to be redrawn when processing the WM_PAINT message (what did you think?). If you set this property to true, then the system will ensure that the background is erased in the entire marked area (which can lead to flickering with frequent redrawing, so this property is set to false by default);

OnPaint - for almost any windowed and non-windowed visual object in KOL, it is possible to override the drawing procedure by assigning a handler for this event (but in this case, your code must provide all the drawing of the client side of the window). Usually such a handler is assigned to a paint box object specially designed for this purpose, sometimes for panels (in fact, panels do not differ from paint box controls except for the presence of text: in KOL, the "paint box" is an ordinary window object, and can serve parent for other visual objects;

OnEraseBkgnd - this event will allow you to define your own procedure for erasing the background. If such a handler is assigned, the system no longer erases the background on its own by the default procedure. If at the same time the handler code does nothing, then the erasure is not performed at all, and if you ensure the correct erasure of the background simultaneously with painting in the OnPaint event handler, this allows you to completely eliminate the flickering of the image during redrawing;

Canvas - the canvas of the visual object. Almost all windows allow you to override or redefine the standard window drawing procedure, for example, see the events OnPaint, OnDrawItem, in this case it is convenient to program the drawing procedure through the methods and properties of the canvas object provided here.