回避由于Unity3D编辑器播放时编译脚本重加载程序集导致报错卡死等问题

Unity3D有一个叫做”live recompile”的功能，即在编辑器处于播放状态时修改脚本代码或替换托管dll等操作时，当场触发重新编译生成项目脚本assembly，并会进行重新加载操作，然而，这个功能很多时候并不能保证重加载后的代码逻辑依然能正常运行，轻则报错，重则卡死。经过博主测试发现，Unity在重加载assembly后，会清空类实例部分成员变量的值（如在Awake中new出的数组对象等），且不负责还原。最终，为了避免由于此导致的问题，采取了一种回避的手段：通过Editor脚本方式检测是否在播放状态时触发了脚本编译，是的话立即停止播放，代码如下：

 // Cape Guy, 2015. Use at your own risk.
 using UnityEngine;
 using UnityEditor;
 
 /// <summary>
 /// This script exits play mode whenever script compilation is detected during an editor update.
 /// </summary>
 [InitializeOnLoad] // Make static initialiser be called as soon as the scripts are initialised in the editor (rather than just in play mode).
 public class ExitPlayModeOnScriptCompile {
     
     // Static initialiser called by Unity Editor whenever scripts are loaded (editor or play mode)
     static ExitPlayModeOnScriptCompile () {
         Unused (_instance);
         _instance = new ExitPlayModeOnScriptCompile ();
     }
 
     private ExitPlayModeOnScriptCompile () {
         EditorApplication.update += OnEditorUpdate;
     }
     
     ~ExitPlayModeOnScriptCompile () {
         EditorApplication.update -= OnEditorUpdate;
         // Silence the unused variable warning with an if.
         _instance = null;
     }
     
     // Called each time the editor updates.
     private static void OnEditorUpdate () {
         if (EditorApplication.isPlaying && EditorApplication.isCompiling) {
             Debug.Log ("Exiting play mode due to script compilation.");
             EditorApplication.isPlaying = false;
         }
     }
 
     // Used to silence the 'is assigned by its value is never used' warning for _instance.
     private static void Unused<T> (T unusedVariable) {}
 
     private static ExitPlayModeOnScriptCompile _instance = null;
 }

参考文章：
Can I disable live recompile? http://answers.unity3d.com/questions/286571/can-i-disable-live-recompile.html