为什么我的程序没有像我需要的那样等待？

Question

Ok pretty much what I am trying to do is have my program wait a predetermined amount of times then move the character to another spot on the grid (which is notated by the "panel_x" and "panel_y" variables). Instead it waits and then moves the character around every frame...Im not sure what I am doing wrong. I believe I need a coroutine, but I may be wrong.

//How I am calling the coroutine
void Update()
    {
       if(HP != 0)
       { 
       StartCoroutine(Wait());
       }
    }

//The Coroutine I need to run to move my character
//around...I need this to run until the character's
//hp reaches 0.
IEnumerator Wait()
    {
        while(true)
        {
            //I need it to wait...  
            yield return new WaitForSeconds(3);
            //Then move the character to another
            //grid...
            panel_x = Random.Range(1, 4);
            panel_y = Random.Range(1, 4);
        }
    }

Answer 1

Update runs on every frame. What's happening here is that you're calling Wait() on every frame which will run multiple instances in an infinite loop.

I believe what you're trying to do is change the x and y values every 3 seconds. If so, try something like this.

float timer = 0.0f;
void Update()
{
    if (HP != 0)
    {
       timer += Time.deltaTime;
       if (timer >= 3)
       {
           panel_x = Random.Range(1, 4);
           panel_y = Random.Range(1, 4);
           timer = 0;
       }
    }
}

Time.deltaTime returns the time passed between frames so it can be used as a timer by summing it every frame. When 3 seconds has passed, we reset the timer to 0 and run our method.

Answer 2

Did you modify that HP ever after? If HP is not 0, then the StartCoroutine(Wait()) will be called every time Update() is executed. That is why you get the weird result.

Answer 3

Your function doesn't seem to take any parameters, so I can provide you other method like Invoke as an alternative.

Invoke(x, y) executes a function after a certain amount of seconds delay. In your case for example:

void Update(){
    if(HP != 0)
        Invoke("MoveChar", 3); //execute MoveChar() after 3 seconds
}

MoveChar(){
    panel_x = Random.Range(1,4);
    panel_y = Random.Range(1,4);
}

Just for your info, there is also InvokeRepeating(x, y, z) which maybe you won't need in this case.
It repeats every z seconds after function x being called with y delay.

void Start(){ 
    //execute MoveChar() after 3 seconds and call the
    //function again after 0.5 seconds repeatedly
    InvokeRepeating("MoveChar", 3, 0.5);
}

MoveChar(){
    panel_x = Random.Range(1,4);
    panel_y = Random.Range(1,4);
}