Unity编辑器中何时需要协程
当我们定制Unity编辑器的时候，往往需要启动额外的协程或者线程进行处理。比如当执行一些界面更新的时候，需要大量计算，如果用户在不断修正一个参数，比如从1变化到2，这种变化过程要经历无数中间步骤，调用N多次Update，如果直接在Update中不断刷新，界面很容易直接卡死。所以在一个协程中进行一些优化，只保留用户最后一次参数修正，省去中间步骤，就会好很多。这属于Unity编辑器的内容，也属于优化的内容，还是放在优化中吧。
解决问题思路
Unity官网的questions里面也有很多人在搜索这个问题，不过后来是看到有个人提到了这个方法。问题的关键点就是“EditorApplication.update ”，有个这样的方法，你把要执行的协程传递给它就可以在编辑器下自动执行循环调用。
老外的写法
当然，后来我也找到一个老外的写法，代码贴出来如下：
using UnityEngine;
using UnityEditor;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.CompilerServices;public static class EditorCoroutineRunner
{
private class EditorCoroutine : IEnumerator
{
private Stack<IEnumerator> executionStack;
{
private class EditorCoroutine : IEnumerator
{
private Stack<IEnumerator> executionStack;
public EditorCoroutine(IEnumerator iterator)
{
this.executionStack = new Stack<IEnumerator>();
this.executionStack.Push(iterator);
}
{
this.executionStack = new Stack<IEnumerator>();
this.executionStack.Push(iterator);
}
public bool MoveNext()
{
IEnumerator i = this.executionStack.Peek();
{
IEnumerator i = this.executionStack.Peek();
if (i.MoveNext())
{
object result = i.Current;
if (result != null && result is IEnumerator)
{
this.executionStack.Push((IEnumerator)result);
}
{
object result = i.Current;
if (result != null && result is IEnumerator)
{
this.executionStack.Push((IEnumerator)result);
}
return true;
}
else
{
if (this.executionStack.Count > 1)
{
this.executionStack.Pop();
return true;
}
}
}
else
{
if (this.executionStack.Count > 1)
{
this.executionStack.Pop();
return true;
}
}
return false;
}
}
public void Reset()
{
throw new System.NotSupportedException("This Operation Is Not Supported.");
}
{
throw new System.NotSupportedException("This Operation Is Not Supported.");
}
public object Current
{
get { return this.executionStack.Peek().Current; }
}
{
get { return this.executionStack.Peek().Current; }
}
public bool Find(IEnumerator iterator)
{
return this.executionStack.Contains(iterator);
}
}
{
return this.executionStack.Contains(iterator);
}
}
private static List<EditorCoroutine> editorCoroutineList;
private static List<IEnumerator> buffer;
private static List<IEnumerator> buffer;
public static IEnumerator StartEditorCoroutine(IEnumerator iterator)
{
if (editorCoroutineList == null)
{
editorCoroutineList = new List<EditorCoroutine>();
}
if (buffer == null)
{
buffer = new List<IEnumerator>();
}
if (editorCoroutineList.Count == 0)
{
EditorApplication.update += Update;
}
{
if (editorCoroutineList == null)
{
editorCoroutineList = new List<EditorCoroutine>();
}
if (buffer == null)
{
buffer = new List<IEnumerator>();
}
if (editorCoroutineList.Count == 0)
{
EditorApplication.update += Update;
}
// add iterator to buffer first
buffer.Add(iterator);
buffer.Add(iterator);
return iterator;
}
}
private static bool Find(IEnumerator iterator)
{
// If this iterator is already added
// Then ignore it this time
foreach (EditorCoroutine editorCoroutine in editorCoroutineList)
{
if (editorCoroutine.Find(iterator))
{
return true;
}
}
{
// If this iterator is already added
// Then ignore it this time
foreach (EditorCoroutine editorCoroutine in editorCoroutineList)
{
if (editorCoroutine.Find(iterator))
{
return true;
}
}
return false;
}
}
private static void Update()
{
// EditorCoroutine execution may append new iterators to buffer
// Therefore we should run EditorCoroutine first
editorCoroutineList.RemoveAll
(
coroutine => { return coroutine.MoveNext() == false; }
);
{
// EditorCoroutine execution may append new iterators to buffer
// Therefore we should run EditorCoroutine first
editorCoroutineList.RemoveAll
(
coroutine => { return coroutine.MoveNext() == false; }
);
// If we have iterators in buffer
if (buffer.Count > 0)
{
foreach (IEnumerator iterator in buffer)
{
// If this iterators not exists
if (!Find(iterator))
{
// Added this as new EditorCoroutine
editorCoroutineList.Add(new EditorCoroutine(iterator));
}
}
if (buffer.Count > 0)
{
foreach (IEnumerator iterator in buffer)
{
// If this iterators not exists
if (!Find(iterator))
{
// Added this as new EditorCoroutine
editorCoroutineList.Add(new EditorCoroutine(iterator));
}
}
// Clear buffer
buffer.Clear();
}
buffer.Clear();
}
// If we have no running EditorCoroutine
// Stop calling update anymore
if (editorCoroutineList.Count == 0)
{
EditorApplication.update -
// Stop calling update anymore
if (editorCoroutineList.Count == 0)
{
EditorApplication.update -
用法就是大概在你自己的类的Start方法中稍作修改，再增加一个协程函数，如下：
void Start()
{
rope = gameObject.GetComponent<QuickRope>();
#if UNITY_EDITOR
//调用方法
EditorCoroutineRunner.StartEditorCoroutine(OnThreadLoop());
#endif
}
public IEnumerator OnThreadLoop()
{
while(true)
{
Debug.Log("Looper");
yield return null;
}
}当然最好是加上#if UNITY_EDITOR预处理了。这个类基本是满足要求了。如果你把你自己的脚本做了这样的修改之后，它是可以在编辑状态不断执行到Loop的，要注意它需要先执行到Start，也就是说，你可能需要把GameObject做成Prefab，然后把它从场景中删除，再把Prefab拖回场景，才会在编辑状态下触发脚本上的Star方法，从而激发Loop。
我的写法
然而，用久了你就会发现几个问题，一旦Loop开始了，你是无法停止的，哪怕你把GameObject从场景中删掉都无济于事，当然隐藏也没有效果。为了解决这个问题，也把脚本弄得简单点儿，我重写了这个脚本，希望需要的同学可以愉快地使用。
using UnityEngine;
using UnityEditor;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.CompilerServices;public static class EditorCoroutineLooper
{
{
private static Dictionary<IEnumerator,MonoBehaviour> m_loopers = new Dictionary<IEnumerator,MonoBehaviour> ();
private static bool M_Started = false;
/// <summary>
/// 开启Loop
/// </summary>
/// <param name="mb">脚本</param>
/// <param name="iterator">方法</param>
public static void StartLoop(MonoBehaviour mb, IEnumerator iterator)
{
if(mb!=null && iterator != null)
{
if(!m_loopers.ContainsKey(iterator))
{
m_loopers.Add(iterator,mb);
}
else
{
m_loopers[iterator]=mb;
}
}
if (!M_Started)
{
M_Started = true;
EditorApplication.update += Update;
}
}
private static List<IEnumerator> M_DropItems=new List<IEnumerator>();
private static void Update()
{
if (m_loopers.Count > 0)
{
private static bool M_Started = false;
/// <summary>
/// 开启Loop
/// </summary>
/// <param name="mb">脚本</param>
/// <param name="iterator">方法</param>
public static void StartLoop(MonoBehaviour mb, IEnumerator iterator)
{
if(mb!=null && iterator != null)
{
if(!m_loopers.ContainsKey(iterator))
{
m_loopers.Add(iterator,mb);
}
else
{
m_loopers[iterator]=mb;
}
}
if (!M_Started)
{
M_Started = true;
EditorApplication.update += Update;
}
}
private static List<IEnumerator> M_DropItems=new List<IEnumerator>();
private static void Update()
{
if (m_loopers.Count > 0)
{
var allItems = m_loopers.GetEnumerator();
while(allItems.MoveNext())
{
var item = allItems.Current;
var mb = item.Value;
//卸载时丢弃Looper
if(mb == null)
{
M_DropItems.Add(item.Key);
continue;
}
//隐藏时别执行Loop
if(!mb.gameObject.activeInHierarchy)
{
continue;
}
//执行Loop，执行完毕也丢弃Looper
IEnumerator ie = item.Key;
if(!ie.MoveNext())
{
M_DropItems.Add(item.Key);
}
}
//集中处理丢弃的Looper
for(int i = 0;i < M_DropItems.Count;i++)
{
if(M_DropItems[i] != null)
{
m_loopers.Remove(M_DropItems[i]);
}
}
M_DropItems.Clear();
}
while(allItems.MoveNext())
{
var item = allItems.Current;
var mb = item.Value;
//卸载时丢弃Looper
if(mb == null)
{
M_DropItems.Add(item.Key);
continue;
}
//隐藏时别执行Loop
if(!mb.gameObject.activeInHierarchy)
{
continue;
}
//执行Loop，执行完毕也丢弃Looper
IEnumerator ie = item.Key;
if(!ie.MoveNext())
{
M_DropItems.Add(item.Key);
}
}
//集中处理丢弃的Looper
for(int i = 0;i < M_DropItems.Count;i++)
{
if(M_DropItems[i] != null)
{
m_loopers.Remove(M_DropItems[i]);
}
}
M_DropItems.Clear();
}
if (m_loopers.Count == 0)
{
EditorApplication.update -= Update;
M_Started = false;
}
}
}
{
EditorApplication.update -= Update;
M_Started = false;
}
}
}
//调用方法原来这个样
EditorCoroutineRunner.StartEditorCoroutine(OnThreadLoop());
//现在改成这个样
EditorCoroutineLooper.StartLoop(this,OnThreadLoop());使用这个脚本的时候，需要传两个参数，一个就是你自己的脚本，另外一个就是协程函数。原理就是代码里面会检测你的脚本状态，当脚本关闭或者卸载的时候，都会停掉Loop调用。老外有时候写代码，也不那么讲究，有没有？
