How can I check the state of Num, Caps, and Scoll Lock?

How can I check the state of Num, Caps, and Scoll Lock?

Applies To: C++Builder 1 or higher
Category: Knowledge Base

Is it possible to know the state of -lock keys such as Num Lock, Caps Lock or Scroll Lock?

Start a new project using File | New Application.

Add three (3) Shapes and set their Brush->Color to clBlack.

Edit the OnShow event of your form:

void __fastcall TForm1::FormShow(TObject *Sender)

{

// Num Lock

if(GetKeyState(VK_NUMLOCK))

Shape1->Brush->Color = clYellow;

// Caps Lock

if(GetKeyState(VK_CAPITAL))

Shape2->Brush->Color = clYellow;

// Scroll Lock

if(GetKeyState(VK_SCROLL))

Shape3->Brush->Color = clYellow;

}

The Win32 API function GetKeyState returns the current state of the specified key.