c++ - 获取键状态函数？

Question

为什么我按下方向箭头 ON 后，函数 GetKeyState 继续给我一个大于 0 的值？

#include <iostream>
#include <windows.h>
using namespace std;

int main()
{
    for(int i = 0; i < 1000; ++i)
    {
        if(GetKeyState(VK_UP))
        {
            cout << "UP pressed" << endl;
        }
        else
            cout << "UP not pressed" << endl;

        Sleep(150);
    }

    return 0;
}

Answer 1

来自documentation :

The key status returned from this function changes as a thread reads key messages from its message queue. The status does not reflect the interrupt-level state associated with the hardware. Use the GetAsyncKeyState function to retrieve that information.

由于您不处理消息，因此您需要调用 GetAsyncKeyState。

像这样测试按下的键:

if (GetAsyncKeyState(VK_UP) < 0)
    // key is pressed