c# Using an IEnumerator yield WaitForSeconds to temporarily pause a While loop

[Reverend-Speed]

So - I see there are numerous questions relating to this issue, but I’ve been unable to find one that scratches this particular itch… or if I have, I’m not savvy enough to recognise it. Please be patient - and if you know of a previously answered question that can clear my problem up, please send it right along. =)

I’m executing a while loop which iterates through an array - but as this naturally crashes Unity, I’m trying to execute a coroutine which will slow the execution to once every 4 seconds (in this case).

In theory: The While loop starts, performs the actions in the For section, encounters StartCoroutine(WaitASec (4.0F)); , bounds off to IEnumerator WaitASec, pauses for 4 seconds, then evaluates the While condition and starts again as long as loophandle is true.

In practice: CRASH.

Using Debug.Logs and inserting the line ‘loophandle = false’ at the end of the While loop seems to indicate that the program reaches the Debug.Log line ‘At end of While Loop’ BEFORE the Debug.Log line ‘Waited a sec’.

So - the newbie is baffled.

Right, code:

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class CameraControllerRevCsharp : MonoBehaviour {

        ...

	//Boolean switch to turn the tracking on and off
	public bool loophandle = true;

        ...

	public void Start() {
		
		Transform target = GameObject.Find("Player").transform;
			while (loophandle){
				Debug.Log ("Started While Loop");
				if(cameraNodes.Count > 0){
					int node = 0;
					for (int i = 0; i < cameraNodes.Count; i++){
						Debug.Log ("Started for section");
						if(cameraNodes_.range >= Vector3.Distance(target.position, cameraNodes*.position))*_

* {*
* node = i;*
* }*
* }*
* Debug.Log (“About to transform camera”);*
* transform.position = ( (CameraNode)cameraNodes[node]).position;*
* }*
* Debug.Log (“Calling StartCoroutine”);*
* StartCoroutine(WaitASec(4.0F));*
* // FOR TESTING: loophandle = false;*
* Debug.Log (“At end of While Loop”);*
* }*
* }*
* IEnumerator WaitASec(float waitTime){*
* yield return new WaitForSeconds(waitTime);*
* Debug.Log (“Waited a sec”);*
* }*

* public void Update (){*
* transform.LookAt(target);*
* Debug.Log (“Looking at target”);*
* }*

}
Thanks for your brain time on this. Here’s hoping you can phrase the solution in plain enough language so I never end up doing this bloody stupid thing again. =)
–Rev

[by0log1c]

Hey there again, I just realized the error while going over the comments on the last question. A while loop need to yield a pause every now and then or it’ll crash the game.

You may do it like this:

while(true)
{
    DoSomething();
    yield return null; //wait for a frame
    yield return new WaitForSeconds(3.14f);
}

EDIT: I notice you actually call a coroutine that does the waiting, that could work but you need to wait for that method to return after itself waited after the yield to return

You’d do something like:

//method return type has to be IEnumerator
IEnumerator Start()
{
    yield return StartCoroutine(MyDelayMethod(3.1415f));
    //3.1415 seconds later
}

IEnumerator MyDelayMethod(float delay)
{
    yield return new WaitForSeconds(delay);
}

[Berenger]

Indeed, calling a coroutine without yielding it’s return value in a while() is just going to start a bazillion (and that’s a lot !) instances of coroutines and freeze the program.

[josetgg]

Just curious, why are you running a while loop on the start function?

[VillainT]

You can use (for javascript)

while (condition) {
//codes
yield WaitForSeconds (0);
}

http://forum.unity3d.com/threads/160337-How-to-use-while-loop-without-crashing-the-game?p=1096760#post1096760