public class BaseCommand
{
 
 //執(zhí)行命令
 public virtual void ExcuteCommand() { }
 
 
 //撤銷命令
 public virtual void RevocationCommand() { }
 
}

public class CommandManager : MonoBehaviour
{
 public static CommandManager Instance = null;
 //管理命令
 private Stack<BaseCommand> commandStack = new Stack<BaseCommand>();
 
 private void Awake()
 {
  Instance = this;
 }
 
 
 //增加命令 
 public void AddCommand(BaseCommand baseCommand)
 {
  commandStack.Push(baseCommand);
 }
 
 
 //移除命令 并且撤銷一步操作
 public void RemoveCommand()
 {
  if(commandStack.Count>0)
  {
   BaseCommand baseCommand = commandStack.Pop();
   baseCommand.RevocationCommand();
  }
 }
}

//保存模型的位置 角度 大小信息
public class TransformCommand : BaseCommand
{
 private Transform target;
 private Vector3 pos;
 private Vector3 rota;
 private Vector3 scale;
 private Transform parent;
//我們在構(gòu)造函數(shù)里直接傳進(jìn)來我們改變狀態(tài)前的Transform信息
 public TransformCommand(Transform target, Vector3 pos, Vector3 rota, Vector3 scale,Transform parent)
 {
  this.target = target;
  this.pos = pos;
  this.rota = rota;
  this.scale = scale;
  this.parent = parent;
 }
 
 public override void ExcuteCommand()
 {
  base.ExcuteCommand();
 }
 
 public override void RevocationCommand()
 {
  target.SetParent(parent);
  target.transform.localPosition = pos;
  target.transform.localEulerAngles = rota;
  target.transform.localScale = scale;
 }
}

public class CameraMove : MonoBehaviour {
 
 
 // Update is called once per frame
 void Update ()
 {
  if(Input.GetKeyDown(KeyCode.W))
  {
   TransformCommand cmd = new TransformCommand(transform,transform.localPosition,
    transform.localEulerAngles,transform.localScale,null);
   CommandManager.Instance.AddCommand(cmd);
   transform.Translate(Vector3.forward,Space.Self);
  }
 }
}

public class Test : MonoBehaviour {
 
 private void Update()
 {
  if(Input.GetKeyDown(KeyCode.Escape))
  {
   CommandManager.Instance.RemoveCommand();
  }
 }
}

public class MyInputField : MonoBehaviour,IPointerClickHandler
{
 private InputField input;
 private string preString;//用來記錄改變前得值
 
 private bool IsValueChange = false;//判斷值是否發(fā)生改變
 
 private bool IsClick = false;//用來判斷InputField是否被選中交互
 
 
 
 private void Awake()
 {
  input = GetComponent<InputField>();
  input.onValueChanged.AddListener(delegate { IsValueChange=true; });
  input.onEndEdit.AddListener(OnEndEditCallBck);
 }
 
 //結(jié)束編輯得回調(diào)函數(shù)
 void OnEndEditCallBck(string content)
 {
  IsClick = false;
  //如果值沒變 直接返回 沒必要增加命令
  if (IsValueChange == false) return;
  InputFieldCommand cmd = new InputFieldCommand(input,preString);
  CommandManager.Instance.AddCommand(cmd);
 }
 
 //當(dāng)被點(diǎn)擊時(shí)，我們的UI組件被交互 有被更改值得可能 所以要記錄當(dāng)前值
 public void OnPointerClick(PointerEventData eventData)
 {
  Debug.Log("點(diǎn)擊");
  if (IsClick) return;
  preString = input.text;
  IsClick = true;
 }
}
public class InputFieldCommand : BaseCommand
{
 private InputField targetInput;
 private string content;
 
 
 public InputFieldCommand(InputField inputField,string content)
 {
  this.targetInput = inputField;
  this.content = content;
 }
 
 
 public override void RevocationCommand()
 {
  base.RevocationCommand();
  targetInput.text = content;
 }
}

public class DestoryCommand : BaseCommand
{
 private List<GameObject> objects;
 
 public DestoryCommand(List<GameObject> objects)
 {
  this.objects = objects;
 }
 
 public override void RevocationCommand()
 {
  for(int i=0;i< objects.Count;i++)
  {
   //利用對象池技術(shù)回收物體 這里就不寫了 因?yàn)檫€要把對象池的腳本添加進(jìn)來
  }
 }
}