The DelphiVCL CleanupInstance method or DelphiVCL.Application.CleanupInstance is used to perform finalization on long strings, variants, and interface variables within a class.
Do not call CleanupInstance directly. CleanupInstance is called automatically when the object instance is destroyed.
CleanupInstance releases all long strings and variants. It sets long strings to empty and variants…
OnMinimize or DelphiVCL.Application.OnMinimize occurs when a Python GUI DelphiVCL application is minimized.
Write an OnMinimize event handler to perform special processing when the application is minimized. The application is minimized either because the user minimizes…
In the DelphiVCL Wiindows UI Toolkit TMonitorDefaultTo specifies which monitor to select when there is no match to the specified criteria.
TMonitorDefaultTo indicates which monitor should be used when the selection criteria do not match any of the monitors in the…
As a part of the DelphiVCL Windows UI Toolkit the DelphiVCL.Timer or TTimer is used to encapsulate the Windows API timer functions.
TTimer is used to simplify calling the Windows API timer functions SetTimer and KillTimer, and to simplify processing the WM_TIMER messages. Use one timer component for each timer in the application.
The execution of the timer occurs through its OnTimer event.
When performing development on Windows, the ComponentState property or DelphiVCL.Application.ComponentState is used to describe the current state of the component, indicating when a component needs to avoid certain actions.
ComponentState is a set of constants defined in…
When carrying out Windows development, use the CurrentHelpFile property or DelphiVCL.Application.CurrentHelpFile to indicate the current Help file.
You can read CurrentHelpFile to determine the name of the Help file that is currently used by the application when it…
The Action parameter in DelphiVCL is used to specify the action associated with the control when carrying out Windows development.
Action is the action object that is associated with the control. Actions allow an application to centralize the response to user commands. When control is associated with an action, the action determines the appropriate properties and events of the control (such as…
The ClassNameIs method or DelphiVCL.Application.ClassNameIs is used to determine whether an object is of a specific type when you develop windows software.
ClassNameIs determines whether an object instance or class reference has a class name that matches a specified…
What Is delphivcl.Picture Used For In Windows Development?
February 18, 2022
DelphiVCL.Picture or TPicture contains a bitmap, icon, metafile graphic, or user-defined graphic. It is used in Windows development to display images to the user as part of the graphical user interface.
DelphiVCL.Picture or TPicture is a TGraphic container, used to hold a…
DelphiVCL.PaintBox or TPaintBox provides a canvas that applications can use for rendering an image when you develop Windows software.
We can use TPaintBox to add custom images to a form. Unlike TImage, which displays an image that is stored in a bitmap, icon, or metafile, TPaintBox requires an application to draw the image directly on a canvas. Use the OnPaint event handler to draw on the paint…
