按下播放按钮时 Unity 冻结

Question

I am learning Unity through an udemy course.

Now I am stuck at a point where unity screen freezes when I hit the play button. It happens in the spawn manager for the random positioned enemies and powerups the IEnumerator for enemy works perfectly, but as soon as I add the same for the powerup, and hit the play button, it freezes.

When I comment out the powerup section in the spawn manager, and restart unity, it works perfectly.

What should I do for my powerup spawn to work?

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

public class SpawnManager : MonoBehaviour
{
    [SerializeField]
    private GameObject _enemyShipPrefab;
    [SerializeField]
    private GameObject[] powerup;

    // Start is called before the first frame update
    void Start()
    {
        StartCoroutine(EnemySpawnRoutine());
        StartCoroutine(PowerupSpawnRoutine());
    }

    public IEnumerator EnemySpawnRoutine()
    {
        while(true)
        {
            float enemyPositionX = Random.Range(-8.34f, 8.34f);
            Instantiate(_enemyShipPrefab, new Vector3(enemyPositionX, 6.39f, 0), Quaternion.identity);
            yield return new WaitForSeconds(5.0f);
        }
    }

    public IEnumerator PowerupSpawnRoutine()
    {
        while(true)
        {
            // float powerupPositionX = Random.Range(-8.622f, 8.622f);
            int randomPowerup = Random.Range(0, 3);
            Instantiate(powerup[randomPowerup], new Vector3(Random.Range(-8.622f, 8.622f), 4.5f, 0), Quaternion.identity);
        }
    }
}

Answer 1

In your PowerupSpawnRoutine the while(true) is always going to run as its an infinite loop. You don't yield anywhere inside it.

You should add a delay in your PowerupSpawnRoutine as well.

public IEnumerator PowerupSpawnRoutine()
{
    while(true)
    {
        // float powerupPositionX = Random.Range(-8.622f, 8.622f);
        int randomPowerup = Random.Range(0, 3);
        Instantiate(powerup[randomPowerup], new Vector3(Random.Range(-8.622f, 8.622f), 4.5f, 0), Quaternion.identity);

        // this e.g. will spawn powerup after every 5 seconds.
        yield return new WaitForSeconds(5.0f); 
    }
}

Answer 2

As already mentioned in by Muhammad Farhan Aqeel you are not yield ing anywhere inside of the while(true) loop in PowerupSpawnRoutine .

---

However, as complete alternative here instead of using Coroutines at all you could also use InvokeRepeating in your use case:

[SerializeField] private float enemySpawnDelay = 5f;
[SerializeField] private float powerupSpawnDelay = 5f;

// Start is called before the first frame update
void Start()
{
    // The first parameter is the initial delay so 0 makes the first call
    // immediately.
    // The second parameter is the repeating delay
    InvokeRepeating(nameof(EnemySpawnRoutine), 0f, enemySpawnDelay);
    InvokeRepeating(nameof(PowerupSpawnRoutine), 0f, powerupSpawnDelay);
}

private void EnemySpawnRoutine()
{
    float enemyPositionX = Random.Range(-8.34f, 8.34f);
    Instantiate(_enemyShipPrefab, new Vector3(enemyPositionX, 6.39f, 0), Quaternion.identity);
}

private void PowerupSpawnRoutine()
{
    // when getting random indices use the actual length of the array to be more
    // flexible and secure against errors
    int randomPowerup = Random.Range(0, powerup.Length);
    Instantiate(powerup[randomPowerup], new Vector3(Random.Range(-8.622f, 8.622f), 4.5f, 0), Quaternion.identity);
}