unity简单设计模式---AManagerClass

 
/// Contribution Create Missing Instance 10/2010: Daniel P. Rossi (DR9885)
 
using UnityEngine;
 using System.Collections; 
 
 /// AManager is a singleton.
 /// To avoid having to manually link an instance to every class that needs it, it has a static property called
 /// instance, so other objects that need to access it can just call:
 ///        AManager.instance.DoSomeThing();
 ///
 public class AManager : MonoBehaviour {
    // s_Instance is used to cache the instance found in the scene so we don‘t have to look it up every time.
    private static AManager s_Instance = null;
 
    // This defines a static instance property that attempts to find the manager object in the scene and
    // returns it to the caller.
    public static AManager instance {
        get {
            if (s_Instance == null) {
                // This is where the magic happens.
                //  FindObjectOfType(...) returns the first AManager object in the scene.
                s_Instance =  FindObjectOfType(typeof (AManager)) as AManager;
            }
 
            // If it is still null, create a new instance
            if (s_Instance == null) {
                GameObject obj = new GameObject("AManager");
                s_Instance = obj.AddComponent(typeof (AManager)) as AManager;
                Debug.Log ("Could not locate an AManager object. \ AManager was Generated Automaticly.");
            }
 
            return s_Instance;
        }
    }
 
    // Ensure that the instance is destroyed when the game is stopped in the editor.
    void OnApplicationQuit() {
        s_Instance = null;
    }
 
    // Add the rest of the code here...
    public void DoSomeThing() {
        Debug.Log("Doing something now", this);
    }
 
 }