Unity5的关卡切换

本文章由cartzhang编写，转载请注明出处。 所有权利保留。
文章链接：http://blog.csdn.net/cartzhang/article/details/51055584
作者：cartzhang

一、Unity关卡

Unity 使用过程中关卡加载和卸载是大多数三维引擎都要提供的基本功能。
因为关卡切换在游戏中非常常用。
在之前的版本中Unity的关卡切换使用的是：

Application.loadedLevel()

看看Application类，此时这个类的功能比较繁杂，比较多。只看与关卡相关的：

        [Obsolete("Use SceneManager.LoadScene")]
        public static void LoadLevel(string name);

        [Obsolete("Use SceneManager.LoadScene")]
        public static void LoadLevel(int index);

        [Obsolete("Use SceneManager.LoadScene")]
        public static void LoadLevelAdditive(string name);

        [Obsolete("Use SceneManager.LoadScene")]
        public static void LoadLevelAdditive(int index);
  //
        // 摘要:
        //     ///
        //     Unloads all GameObject associated with the given scene. Note that assets are
        //     currently not unloaded, in order to free up asset memory call Resources.UnloadAllUnusedAssets.
        //     ///
        //
        // 参数:
        //   index:
        //     Index of the scene in the PlayerSettings to unload.
        //
        //   scenePath:
        //     Name of the scene to Unload.
        //
        // 返回结果:
        //     ///
        //     Return true if the scene is unloaded.
        //     ///
        [Obsolete("Use SceneManager.UnloadScene")]
        public static bool UnloadLevel(string scenePath);
        //
        // 摘要:
        //     ///
        //     Unloads all GameObject associated with the given scene. Note that assets are
        //     currently not unloaded, in order to free up asset memory call Resources.UnloadAllUnusedAssets.
        //     ///
        //
        // 参数:
        //   index:
        //     Index of the scene in the PlayerSettings to unload.
        //
        //   scenePath:
        //     Name of the scene to Unload.
        //
        // 返回结果:
        //     ///
        //     Return true if the scene is unloaded.
        //     ///
        [Obsolete("Use SceneManager.UnloadScene")]
        public static bool UnloadLevel(int index);

这是之前的Application中的关卡的加载和卸载。
当然现在在新版本（Unity5.3以上）中，有了新的变化，那就是SceneManager类了处理。

二、Untiy的SceneManager类

自从Unity5.3版本，Unity 的关卡切换就添加了新的SceneManager的类来处理。
当然要安装过了Unity文档帮助，并且给下面路径一样，就可以知道在本地打开。
本地链接：
file:///C:/Program%20Files/Unity5.3.0/Editor/Data/Documentation/en/Manual/UpgradeGuide53.html
也可以在Unity中搜索SceneManager来查看。

#region 程序集 UnityEngine, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null
// H:UnityUnityProjectShiftLevelsLibraryUnityAssembliesUnityEngine.dll
#endregion

using UnityEngine.Internal;

namespace UnityEngine.SceneManagement
{
    //
    // 摘要:
    //     ///
    //     Scene management at run-time.
    //     ///
    public class SceneManager
    {
        public SceneManager();


        public static int sceneCount { get; }
        //

        public static int sceneCountInBuildSettings { get; }


        public static Scene GetActiveScene();

        public static Scene[] GetAllScenes();
        // 参数:
        //   index:
        //     Index of the scene to get. Index must be greater than or equal to 0 and less
        //     than SceneManager.sceneCount.
        public static Scene GetSceneAt(int index);

        // 返回结果:
        //     ///
        //     The scene if found or an invalid scene if not.
        //     ///
        public static Scene GetSceneByName(string name);

        //     Searches all scenes added to the SceneManager for a scene that has the given
        //     asset path.
        //     ///
        //
        // 参数:
        //   scenePath:
        //     Path of the scene. Should be relative to the project folder. Like: "AssetsMyScenesMyScene.unity".
        public static Scene GetSceneByPath(string scenePath);
        [ExcludeFromDocs]
        public static void LoadScene(int sceneBuildIndex);
        [ExcludeFromDocs]
        public static void LoadScene(string sceneName);

        // 参数:
        //   sceneName:
        //     Name of the scene to load.
        //
        //   sceneBuildIndex:
        //     Index of the scene in the Build Settings to load.
        //
        //   mode:
        //     Allows you to specify whether or not to load the scene additively. See SceneManagement.LoadSceneMode
        //     for more information about the options.
        public static void LoadScene(int sceneBuildIndex, [DefaultValue("LoadSceneMode.Single")] LoadSceneMode mode);

        // 参数:
        //   sceneName:
        //     Name of the scene to load.
        //
        //   sceneBuildIndex:
        //     Index of the scene in the Build Settings to load.
        //
        //   mode:
        //     Allows you to specify whether or not to load the scene additively. See SceneManagement.LoadSceneMode
        //     for more information about the options.
        public static void LoadScene(string sceneName, [DefaultValue("LoadSceneMode.Single")] LoadSceneMode mode);
        [ExcludeFromDocs]
        public static AsyncOperation LoadSceneAsync(int sceneBuildIndex);
        [ExcludeFromDocs]
        public static AsyncOperation LoadSceneAsync(string sceneName);

        // 参数:
        //   sceneName:
        //     Name of the scene to load.
        //
        //   sceneBuildIndex:
        //     Index of the scene in the Build Settings to load.
        //
        //   mode:
        //     If LoadSceneMode.Single then all current scenes will be unloaded before loading.
        public static AsyncOperation LoadSceneAsync(int sceneBuildIndex, [DefaultValue("LoadSceneMode.Single")] LoadSceneMode mode);

        // 参数:
        //   sceneName:
        //     Name of the scene to load.
        //
        //   sceneBuildIndex:
        //     Index of the scene in the Build Settings to load.
        //
        //   mode:
        //     If LoadSceneMode.Single then all current scenes will be unloaded before loading.
        public static AsyncOperation LoadSceneAsync(string sceneName, [DefaultValue("LoadSceneMode.Single")] LoadSceneMode mode);
        //

        // 参数:
        //   sourceScene:
        //     The scene that will be merged into the destination scene.
        //
        //   destinationScene:
        //     Existing scene to merge the source scene into.
        public static void MergeScenes(Scene sourceScene, Scene destinationScene);
        //
        // 摘要:
        //     ///
        //     Move a GameObject from its current scene to a new scene. /// It is required that
        //     the GameObject is at the root of its current scene.
        //     ///
        //
        // 参数:
        //   go:
        //     GameObject to move.
        //
        //   scene:
        //     Scene to move into.
        public static void MoveGameObjectToScene(GameObject go, Scene scene);
        //

        // 返回结果:
        //     ///
        //     Returns false if the scene is not loaded yet.
        //     ///
        public static bool SetActiveScene(Scene scene);

        //     ///
        public static bool UnloadScene(string sceneName);
        //
        // 摘要:
        //     ///
        //     Unloads all GameObjects associated with the given scene. Note that assets are
        //     currently not unloaded, in order to free up asset memory call Resources.UnloadAllUnusedAssets.
        //     ///
        //
        // 参数:
        //   sceneBuildIndex:
        //     Index of the scene in the Build Settings to unload.
        //
        //   sceneName:
        //     Name of the scene to unload.
        //
        // 返回结果:
        //     ///
        //     Returns true if the scene is unloaded.
        //     ///
        public static bool UnloadScene(int sceneBuildIndex);
    }
}

注意的是这里面还有可以带对象来在关卡中移动的，还有穿越功能啊！！哈哈

三、5.3的实现代码

上代码：

/**************************************************************************
Copyright:@cartzhang
Author: cartzhang
Date: 2016-04-01
Description:加载关卡，可以分组加载和卸载。使用Unity版本为5.3.0.
因为里面使用了场景管理的一个类，这个类在5.3.0以上版本才添加的。
测试操作：使用空格键来切换场景，然后间隔5秒后才开始卸载。
**************************************************************************/
using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;

[System.Serializable]
public class LevelOrder
{

    [Header("每组关卡名称")]
    public string[] LevelNames;
}

public class ChangLevelsHasMain : MonoBehaviour
{
    [Header("所有关卡列表")]
    public LevelOrder[] levelOrder;
    private static int index;
    private int totalLevels = 0;
    private int levelOrderLength;

    void Start ()
    {
        for (int i = 0; i < levelOrder.Length; i++)
        {
            totalLevels += levelOrder[i].LevelNames.Length;
        }

        if (totalLevels != SceneManager.sceneCountInBuildSettings)
        {

        }
        levelOrderLength = levelOrder.Length;
    }

    // Update is called once per frame
    void Update ()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            bool isOk = LoadNextLevels();
            if (isOk)
            {
                InvokeRepeating("UnloadLastLevel", 2.0f, 5);
            }
        }
    }

    bool LoadNextLevels()
    {
        bool bResult = true;
        //index = index % levelOrderLength;
        if (index < 0 || index >= levelOrderLength)
        {
            bResult = false;
            return bResult;
        }

        int LoadTimes = levelOrder[index].LevelNames.Length;
        for (int i = 0; i < LoadTimes; i++)
        {
            SceneManager.LoadSceneAsync(levelOrder[index].LevelNames[i], LoadSceneMode.Additive);
        }
        return bResult;
    }

    void UnloadLastLevel()
    {
        if (index == 0)
        {
            index++;
            CancelInvoke("UnloadLastLevel");
            return;
        }
        // 上一組的關卡
        int TmpLast = (index - 1) >= 0 ? (index - 1) : levelOrderLength - 1;
        int LoadTimes = levelOrder[index].LevelNames.Length;
        for (int i = 0; i < LoadTimes; i++)
        {
            Scene Tmp = SceneManager.GetSceneByName(levelOrder[index].LevelNames[i]);
            if (!Tmp.isLoaded)
            {
                return;
            }
        }

        // 下一關卡全部加載完畢後，卸載之前關卡
        for (int i = 0; i < levelOrder[TmpLast].LevelNames.Length; i++)
        {
            SceneManager.UnloadScene(levelOrder[TmpLast].LevelNames[i]);
        }
        index++;
        CancelInvoke("UnloadLastLevel");
    }
}

就这样就可以了。
代码主要是按组来加载关卡，然后按组来卸载。
测试中，按下空格键来加载，每组关卡在一定时间后，（这里设置的5秒）自动卸载前一组关卡。这里主地图是不卸载的，会一直存在的。

怎么设置的呢？首先需要在Build setting中中把所有要处理的关卡放进来。要不就会在加载过程中报错。
如下图：

然后把代码挂在主地图的任意对象对象上就可以了。

四、测试结果

随意做了几张地图，不那么好看。但是功能很明显。
第一组：

第二组

第三组

参考

file:///C:/Program%20Files/Unity5.3.0/Editor/Data/Documentation/en/Manual/UpgradeGuide53.html

追加Github地址：https://github.com/cartzhang/ShiftLevels

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若有问题，请随时联系！！
非常感谢！！
你在桥上看风景，我在楼里加班！