Question

当play.x的值肯定为1或-1时，为什么不能读取if语句？

如果您需要其他任何帮助，我将竭尽全力为您解释。

public class WhyDosntThisWork : MonoBehaviour
{
    public bool North = false;
    public bool South = false;
    public bool West = false;
    public bool East = false;
    public bool jimmy = false;
    public float x = 0;
    public float y = 0;
    public bool IsRotating = false;
    public Vector3 Player;
    public float if0trueifnotfalse = 0;

    void Start()
    {
        //Player = transform.up;// tryed here aswell still no work
    }

    void Update()
    {
        Player = transform.up;
        y = Input.GetAxisRaw("Vertical");// press arrowkey 
        x = Input.GetAxisRaw("Horizontal");// press arrowkey 
        print(" y =  " + y);
        print(" x =  " + x);
        if (y == 0)
        {
            WereAreWeLooking();// run function  should work???
            print("we are Running the Script");
        }
        if (y > 0)
        {
            print("We Presed up player.x is now 1");
            transform.eulerAngles = new Vector3(0,0,-90); // this changes player.x from -1 to 1
        }
        if (y < 0)
        {
            print("We Presed down player.x is now -1");
           // WereAreWeLooking();
            transform.eulerAngles = new Vector3(0,0,90); //this changes player.x from 1 to -1

        }
    }

    void WereAreWeLooking()
    {
        print("HI we are checking for bools Player.x  IS " + Player.x + " so why dont we change the bool");
        if (Player.x == -1)// this never runs even tho play.x is -1
        {   
            print("We Are GoingUp");
            North = true;
            South = false;
            East = false;
            West = false;
        }
        else if (Player.x == 1)
        {
            print("We Are GoingDown");
            South = true;
            North = false;
            East = false;
            West = false;
        }
        else if (Player.z == 1)
        {
            print("We Are going East");
            East = true;
            South = false;
            North = false;
            West = false;
        }
        else if (Player.z == -1)
        {
            print("We Aregoing west");
            West = true;
            East = false;
            South = false;
            North = false;
        }
        print("Thanks Checking done");
        jimmy = true;

        if (if0trueifnotfalse == 1)// this works if i change the value in the inspector
        {
            jimmy = false;
            print("jimmy is 1");
        }
    }
}

Answer 1

您正在通过相等运算符比较浮点数。

如果计算出该值，则很有可能该值将不完全是1或-1。例如，它将是1.0000000001或0.9999999999。

这意味着您的测试是这样的：

if (Player.x == -1)

将始终失败。

您需要在测试中引入四舍五入：

if (Player.x + 1 < 10e-6)

这将检查Player.x等于-1到6个小数位，因此-0.999999和-1.000001将通过测试。您可能需要调整epsilon值才能获得稳定的数据解决方案。

使用Unity时，您可以使用其内置功能Mathf.Approximately：

if (Mathf.Approximately(Player.x, -1.0f))

即使您使用double，您也仍然会遇到这些舍入错误-尽管减少了很多。可能是因为您用来检查值的任何东西都在执行一些舍入操作，所以看起来值是-1或1。

if语句即使为true也不会起作用

1 个答案: