如何确保在 C# 中没有按下按钮？

Question

So I'm currently making a game in C# and I've added the ability sprint by pressing and holding left shift but the problem is that I don't want the player to be able to sprint while crouching which can happen at the moment so long as the are holding down both left shift and left control. I've tried 'GetButtonUp' and 'GetButtonDown' but they don't work at all. Here is my current sprint script with the issue:

public class AdvancedMovement : MonoBehaviour
{
    //Variables;
    PlayerMovement basicMovementScript;
    public float speedBoost = 10f;

    // Start is called before the first frame update
    void Start()
    {
        basicMovementScript = GetComponent<PlayerMovement>();
    }

    // Update is called once per frame
    void Update()
    {

        if (Input.GetKeyDown(KeyCode.LeftShift))
            beginSprint();
        else if (Input.GetKeyUp(KeyCode.LeftShift))
            endSprint();
    }

    private void beginSprint()
    {
        basicMovementScript.speed += speedBoost;
    }

    private void endSprint()
    {
        basicMovementScript.speed -= speedBoost;
    }
}

I would greatly appreciate some help. Thanks.

Answer 1

Input.GetKeyDown and Input.GetKeyUp are only called once, and that's when the action is made and the next frame is rendered.

If by any misfortune that specific frame is skipped, either for performance or debugging reasons, they could lead to unexpected behavior. which in your case could possibly translate into endSprint being called without the Input.GetKeyDown(KeyCode.LeftShift) being detected as an example.

What I suggest is that you use Input.GetKey instead, which is called at every update, so long as the Key is held down.

In your case, you could do:

if (Input.GetKeyDown(KeyCode.LeftShift) &&.Input.GetKey(KeyCode.Leftcontrol)) which will make sure the Left Ctrl Key is not held down.

What I would also do in a similar situation, instead of using Input.GetKeyDown(KeyCode.LeftShift) I would create a flag _isSprinting and use it in a way similar to the following:

void Update()
{

    if (!_isSprinting && Input.GetKey(KeyCode.LeftShift) && !Input.GetKey(KeyCode.Leftcontrol)))
    {
        beginSprint();

        _isSprinting = true;
    }

    if (_isSprinting && !Input.GetKey(KeyCode.LeftShift))
    {
        endSprint();

        _isSprinting = false;
    }
}