How can I change the state of Caps Lock?

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

Getting the state of Caps Lock as shown in How can I check the state of Num, Caps, and Scroll Lock? was quite easy. I need now to change this state. Is it possible?

 

1.

  Start a new project using File | New Application.

 

2.

  Add two (2) Buttons.

 

3.

  Set their OnClick event to:

 

void __fastcall TForm1::Button1Click(TObject *Sender)

{

    // Enable Caps Lock

    unsigned char key[256];

    GetKeyboardState(key);

    key[VK_CAPITAL] = 1;

    SetKeyboardState(key);

}

 

void __fastcall TForm1::Button2Click(TObject *Sender)

{

    // Disable Caps Lock

    unsigned char key[256];

    GetKeyboardState(key);

    key[VK_CAPITAL] = 0;

    SetKeyboardState(key);

}

 

The Win32 API function SetKeyboardState allows you to change this state.

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