GetKeyState() Verständnisproblem

[wuehfbkjucvf]

struct key_type {
	int key;
	key_state state{ key_state::none };

	void get() {
		SHORT k = GetKeyState(key);

		if (key < 0)
			state = key_state::down;

		else if (key&1 != 0)
			state = key_state::toggled;

		else
			state = key_state::up;
	}
};

#include <iostream>

int main() {
	key_type k;
	k.key = 0x14;

	while (true) {
		k.get();

		if (k.state == key_state::down)
			std::cout << "down\n";

		else if (k.state == key_state::toggled)
			std::cout << "toggled\n";
	}
}

Warum ist egal wie oft und wie lang ich CAPS drücke der Key immer auf key_state::up?

Return value

Type: SHORT

The return value specifies the status of the specified virtual key, as follows:

If the high-order bit is 1, the key is down; otherwise, it is up.
If the low-order bit is 1, the key is toggled. A key, such as the CAPS LOCK key, is toggled if it is turned on. The key is off and untoggled if the low-order bit is 0. A toggle key's indicator light (if any) on the keyboard will be on when the key is toggled, and off when the key is untoggled.

Wenn das high-order bit 1 ist, ist der Key down. Short ist signed, deshalb if(key < 0).

Ansonsten, wenn gesetzt, dann key&1 (damit prüfe ich den lowest bit).

Ansonsten up.

[Mox]

wuehfbkjucvf schrieb:

Warum ist egal wie oft und wie lang ich CAPS drücke der Key immer auf key_state::up?

Die Antwort steht in den Remarks: "The key status returned from this function changes as a thread reads key messages from its message Queue."

Die liest gar keine Messages (GetMessage), und deswegen ändert sich nichts. Versuch's mit GetAsyncKeyState.