public class Level
{
	/// <summary>
	/// 关卡ID
	/// </summary>
	public string ID;

	/// <summary>
	/// 关卡名称
	/// </summary>
	public string Name;

	/// <summary>
	/// 关卡是否解锁	
	/// </summary>
	public bool UnLock = false;
}

<?xml version="1.0" encoding="utf-8"?>
<levels>
  <level id="0" name="level0" unlock="1" />
  <level id="1" name="level1" unlock="0" />
  <level id="2" name="level2" unlock="0" />
  <level id="3" name="level3" unlock="0" />
  <level id="4" name="level4" unlock="0" />
  <level id="5" name="level5" unlock="0" />
  <level id="6" name="level6" unlock="0" />
  <level id="7" name="level7" unlock="0" />
  <level id="8" name="level8" unlock="0" />
  <level id="9" name="level9" unlock="0" />
</levels>

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

public static class LevelSystem 
{
	/// <summary>
	/// 加载Xml文件	
	/// </summary>
	/// <returns>The levels.</returns>
	public static List<Level> LoadLevels()
	{
		//创建Xml对象
		XmlDocument xmlDoc = new XmlDocument();
		//如果本地存在配置文件则读取配置文件
		//否则在本地创建配置文件的副本
		//为了跨平台及可读可写，需要使用Application.persistentDataPath
		string filePath = Application.persistentDataPath + "/levels.xml";
		if (!IOUntility.isFileExists (filePath)) {
			xmlDoc.LoadXml (((TextAsset)Resources.Load ("levels")).text);
			IOUntility.CreateFile (filePath, xmlDoc.InnerXml);
		} else {
			xmlDoc.Load(filePath);
		}
		XmlElement root = xmlDoc.DocumentElement;
		XmlNodeList levelsNode = root.SelectNodes("/levels/level");
		//初始化关卡列表
		List<Level> levels = new List<Level>();
		foreach (XmlElement xe in levelsNode) 
		{
			Level l=new Level();
			l.ID=xe.GetAttribute("id");
			l.Name=xe.GetAttribute("name");
			//使用unlock属性来标识当前关卡是否解锁
			if(xe.GetAttribute("unlock")=="1"){
				l.UnLock=true;
			}else{
				l.UnLock=false;
			}

			levels.Add(l);
		}

		return levels;
	}

	/// <summary>
	/// 设置某一关卡的状态
	/// </summary>
	/// <param name="name">关卡名称</param>
	/// <param name="locked">是否解锁</param>
	public static void SetLevels(string name,bool unlock)
	{
		//创建Xml对象
		XmlDocument xmlDoc = new XmlDocument();
		string filePath=Application.persistentDataPath + "/levels.xml";
		xmlDoc.Load(filePath);
		XmlElement root = xmlDoc.DocumentElement;
		XmlNodeList levelsNode = root.SelectNodes("/levels/level");
		foreach (XmlElement xe in levelsNode) 
		{
			//根据名称找到对应的关卡
			if(xe.GetAttribute("name")==name)
			{
				//根据unlock重新为关卡赋值
				if(unlock){
					xe.SetAttribute("unlock","1");
				}else{
					xe.SetAttribute("unlock","0");
				}
			}
		}

		//保存文件
		xmlDoc.Save (filePath);
	}
}

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;
using System.Xml.Serialization;

public class Main : MonoBehaviour 
{
	//关卡列表
	private List<Level> m_levels;

	void Start () 
	{
		//获取关卡
		m_levels = LevelSystem.LoadLevels ();
		//动态生成关卡
		foreach (Level l in m_levels) 
		{
			GameObject prefab=(GameObject)Instantiate((Resources.Load("Level") as GameObject));
			//数据绑定
			DataBind(prefab,l);
			//设置父物体
			prefab.transform.SetParent(GameObject.Find("UIRoot/Background/LevelPanel").transform);
			prefab.transform.localPosition=new Vector3(0,0,0);
			prefab.transform.localScale=new Vector3(1,1,1);
			//将关卡信息传给关卡
			prefab.GetComponent<LevelEvent>().level=l;
			prefab.name="Level";
		}

		//人为解锁第二个关卡
		//在实际游戏中玩家需要满足一定条件方可解锁关卡
		//此处仅作为演示
		LevelSystem.SetLevels ("level1", true);

	}
	

	/// <summary>
	/// 数据绑定
	/// </summary>
	void DataBind(GameObject go,Level level)
	{
		//为关卡绑定关卡名称
		go.transform.Find("LevelName").GetComponent<Text>().text=level.Name;
		//为关卡绑定关卡图片
		Texture2D tex2D;
		if(level.UnLock){
			tex2D=Resources.Load("nolocked") as Texture2D;
		}else{
			tex2D=Resources.Load("locked") as Texture2D;
		}
		Sprite sprite=Sprite.Create(tex2D,new Rect(0,0,tex2D.width,tex2D.height),new Vector2(0.5F,0.5F));
		go.transform.GetComponent<Image>().sprite=sprite;
	}
}

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class LevelEvent : MonoBehaviour
{
	//当前关卡
	public Level level;

	public void OnClick()
	{
		if(level.UnLock){
			//假设关卡的名称即为对应场景的名称
			//Application.LoadLevel(level.Name);
			Debug.Log ("当前选择的关卡是:"+level.Name);
		}else{
			Debug.Log ("抱歉!当前关卡尚未解锁!");
		}

	}

}