TDBMemo.KeyDown procedure

Declaration

procedure KeyDown(var Key: Word; Shift: TShiftState); override

Arguments

Description

KeyDown is an overridden method used to handle key down events in the control.

Key is the virtual key code examined and handled in the method. Shift is the Shift-Ctrl-Alt modifier for the virtual key code.

KeyDown calls the inherited method to handle the key down event in the method form ancestor class. If Key is not already applied, it is checked for the following values:

VK_ESCAPE

Editing is being cancelled. Calls the Reset method in the TFieldDataLink instance used in the class. Call SelectAll to re-select content in the control. Sets Key to VK_UNKNOWN to indicate that it was handled in the method.

VK_DELETE, VK_BACK

Content is being removed in the control. If the Field in the internal TFieldDataLink is not editable, the value in Key is set VK_UNKNOWN.

For the macOS (Darwin) platform, additional virtual key codes are detected (and discarded) if the contents of the field in the linked dataset cannot be modified. These keys include:

VK_0..VK_9

numeric characters not on the numeric keypad

VK_A..VK_Z

alphabetic characters

VK_SPACE

space character

VK_NUMPAD0..VK_NUMPAD9

numeric digits on the numeric keypad

VK_MULTIPLY, VK_DIVIDE, VK_ADD, VK_SUBTRACT

operators on the numeric keypad

VK_SEPARATOR, VK_DECIMAL

padded and non-padded Decimal separators

VK_OEM_1

';:' keycap on the US standard keyboard

VK_OEM_2

'/?' keycap on the US standard keyboard

VK_OEM_3

'`~' keycap on the US standard keyboard

VK_OEM_4

'[{' keycap on the US standard keyboard

VK_OEM_5

'\|' keycap on the US standard keyboard

VK_OEM_6

']}' keycap on the US standard keyboard

VK_OEM_7

''"' (Apostrophe and Quote) keycap on the US standard keyboard

VK_OEM_8

miscellaneous character; varies by keyboard layout

For these macOS-specific keys, the value in Key is set to 0 if the field cannot be modified.

Modified in LCL version 3.6 to handle additional data keys on the macOS (Darwin) platform.

See also

• TWinControl.KeyDown