Unity3D 基本撤消脚本

Question

目前，我正在尝试在我的游戏中设置一个基本的撤消功能。在我的设置中，我只是试图将游戏对象设置为活动状态，从假到真。我已经添加了 undo.recordobject 以便 unity 可以跟踪更改，但是之后我需要做什么？我想创建一个按钮，允许最终用户撤消之前的操作。我的代码中目前缺少哪些步骤让我的软件执行撤消选项？

using System.Collections;
using UnityEngine;
using UnityEngine.UI;
using System;
using UnityEditor;

public class LoadAssets : MonoBehaviour
{    
    public GameObject Mud;
    public GameObject DrillFormationMain;
    public GameObject DrillFormation1;
    public GameObject DrillFormation2;
    public GameObject DrillFormation3;

    int count = 0;

    public void DrillHole()
    {
        if (count == 0)
        {
            Mud.SetActive(true);
            DrillFormationMain.SetActive(false);
            DrillFormation1.SetActive(true);

            Undo.RecordObject(DrillFormationMain, "Change");
            DrillFormationMain.transform.position = Vector3.zero;
        }

        else if (count == 1)
        {
            DrillFormation1.SetActive(false);
            DrillFormation2.SetActive(true);

            Undo.RecordObject(DrillFormation1, "Change1");
            DrillFormation1.transform.position = Vector3.zero;
        }  
        count++;
    }   
}

Answer 1

Undo 是 UnityEditor 命名空间的一部分。

此命名空间（因此得名）仅存在于 Unity 编辑器本身中，并在构建中被完全删除

=> 您不能使用其中的任何内容，当然 Undo.RecordObject 用于实际的运行时代码，但只能用于自定义编辑器脚本。

您将不得不为您的 undo/redo 系统想出另一个解决方案。

一个非常简化的示例可能类似于

public class UndoableAction
{
    public UndoableActionType Type;
    public UnityEngine.Object target;
    public object from;
    public object to;

    public UndoableAction(UndoableActionType type, UnityEngine.Object target, object from, object to)
    {
        Type = type;
        Target = target;
        From = from;
        To = to;
    }
}

public enum UndoableActionType
{
    Enable,
    SetActive,
    Position,

    // ... according to your needs
}

public class UndoRedoSystem : MonoBehaviour
{
    private Stack<UndoableAction> availableUndos = new Stack<UndoableAction>();
    private Stack<UndoableAction> availableRedos = new Stack<UndoableAction>();

    public void TrackChangeAction(UndoableActionType type, UnityEngine.Object target, object from, object to)
    {
        // if you change something redo is cleared
        availableRedos.Clear();

        // Add this action do undoable actions
        availableUndos.Push(new UndoableAction(type, target, from, to));
    }

    public void Redo()
    {
        if(availableRedos.Count == 0) return;

        // get latest entry added to available Redos
        var redo = availableRedos.Pop();

        switch(redo.Type)
        {
            case UndoableActionType.Enable:
                ((Component) redo.target).enabled = (bool)redo.To;
                break;

            case UndoableActionType.SetActive:
                ((GameObject) redo.target).SetActive((bool) redo.To);
                break;

            case UndoableActionType.Position:
                ((Transform) redo.target).position = (Vector3) redo.To;
                break;

            // ... According to your needs 
        }

        // finally this is now a new undoable action
        availableUndos.Push(redo);
    }

    public void Undo()
    {
        if(availableUndos.Count == 0) return;

        // get latest entry added to available Undo
        var undo = availableUndos.Pop();

        switch(undo.Type)
        {
            case UndoableActionType.Enable:
                ((Component) undo.target).enabled = (bool)undo.From;
                break;

            case UndoableActionType.SetActive:
                ((GameObject) undo.target).SetActive((bool) undo.From);
                break;

            case UndoableActionType.Position:
                ((Transform) undo.target).position = (Vector3) undo.From;
                break;

            // ... According to your needs 
        }

        // finally this is now a new  redoable action
        availableRedos.Push(undo);
    }
}

现在您可以做一些事情，例如

SomeGameObject.SetActive(true);

undoSystemReference.TrackChange((UnityEngine.Object)SomeGameObject, (object)false, (object)true);

然后在某个地方

undoSystemReference.Undo();

这当然非常简单并且容易出错。

注意 在智能手机上打字，所以没有保修，但我希望这个想法能清楚

Unity3D 基本撤消脚本

Unity3D Basic Undo scripting

c#

undo-redo

unity3d