The ClassType method or DelphiVCL.Application.ClassType is used to return the class reference for the object’s class.
Note: ClassType dynamically determines the type of an object and returns its class reference, or metaclass.
Avoid using ClassType in application code.
Let’s browse all the properties, methods, and built-in properties of the…
The ClassName method or DelphiVCL.Application.ClassName is used to return a string indicating the type of the object instance (as opposed to the type of the variable passed as an argument).
Use ClassName to obtain the class name from an object instance or class…
The ClassInfo method or DelphiVCL.Application.ClassInfo is used to return a pointer to the run-time type information (RTTI) table for the object type.
ClassInfo provides access to the RTTI table for a given object type.
Some classes do not provide run-time type…
The CancelHint method or DelphiVCL.Application.CancelHint is used to cancel the display of a hint for a control.
Applications rarely, if ever, call CancelHint directly. CancelHint is used internally to cancel the display of hints at appropriate times, such as when a window is not valid or when the application closes. CancelHint calls a series of routines that clean up the display and timing…
Learn Python With How I Solved My NYC Parking Problem Using Python by Jessica Garson (PyCon 2020) Video
June 5, 2021
Python programming language is one of the widely used programming languages in the world. It is often described as an easy-to-use language and is most ideal for beginners. We have learned from the previous videos from the recently concluded PyCon 2020 that Python has been…
We use Caption to specify a text string that identifies the control to the user.
To underline a character in a Caption that labels a component, include an ampersand (&) before the character. This type of character is called an accelerator character. The user can…
We use the Parent property to get or set the parent of the control. The parent of a control is the control that contains it. For example, if an application includes three radio buttons in a group box, the group box is the parent of the three radio buttons, and the radio buttons are the child controls of the group box.
To serve as a parent, a control must be an instance of a TWinControl…
We use TextRect to write a string inside a clipping rectangle or within a limited rectangular region. Any portions of the string that fall outside the rectangle passed in the Rect parameter are clipped and don’t appear. The upper left corner of the text is placed at…
OnClose event occurs when the form closes.
We use OnClose to perform special processing when the form closes. The OnClose event specifies which event handler to call when a form is about to close. The handler specified by OnClose might, for example, test to make sure…
OnSelectCell event occurs before a cell in the grid is selected.
Write an OnSelectCell event handler to specify whether any particular cell in the grid can be selected. The Col and Row parameters indicate the column and row indexes of the cell that is about to be selected. Set the CanSelect parameter to False to prevent the cell being selected.
Here is the working example of the…
