在調用一些簡單的方法實現一系列的動作時,回退的問題比較重要。作爲一款用戶體驗良好的產品而言,有回退功能將顯得比較人性化,想想如果我們常用的window,在刪除一個文件後無法恢復將變得多麼的糟糕。更爲直觀的例子是在玩一些小遊戲時,比如象棋、推箱子,提供了悔棋的功能,用戶有了更多選擇的餘地。
本文主要將的將是在Unity中實現一個以常聽說的命令模式爲設計原理,實現一個可以撤銷移動、旋轉、顏色和文字信息的小Demo。
命令模式,主要成員有提出要求的客戶、設置命令的收集者、執行命令的接收者。客戶要求很簡單,點擊按扭就要實現一項目具體的效果,設置命令的收集者無需要知道命令如何執行,只需要爲執行者做好配製。用命令的執行者將執行一個方法,所有的命令者是繼承於有這個方法的接口的類。
抽象到程序代碼中,這三類成員分別對應於界面上的用戶,RemoteControl (這裏是隨便命名的),RemoteLoader
先製作如上的界面,方便你比較直觀的認識,其中左邊兩個是用於切換選擇不同的命令。下面第一個按扭可以執行選中的命令,第二個按扭可以進行撤銷操作。
程序,UGUI面局如下,在Canvas下分別設置了執行者和配製者。
製作好界面之後就可以來實現具體的腳本編輯了,分別創建好接口ICommand,配製腳本RemoteLoader和執行腳本RemoteControl,結構如下:
在Commonds中,分別編寫了用於移動,旋轉,顏色,文字的腳本
這樣一來,就可以實現一個可撤銷的命令模式了,效果如下所示:
其中用於保存undo方法和具體怎麼undo都是使用Stack來實現的,下面分別是部分代碼實現 :
一、接口
public interface ICommand
{
void Execute();
void UnDo();
}
二、執行器
public class RemoteControl : MonoBehaviour {
public Button ctrlBtn;
public Button undoBtn;
public Text ctrlName;
private ICommand icommand;
public Stack<UnityAction> undoFunctions = new Stack<UnityAction>();
void Awake(){
ctrlBtn.onClick.AddListener(OnCtrlBtnClicked);
undoBtn.onClick.AddListener(OnUnDoBtnClicked);
}
public void SetText(string textinfo)
{
ctrlName.text = textinfo;
}
public void SetCommond(ICommand icommand)
{
this.icommand = icommand;
}
/// <summary>
/// 執行
/// </summary>
public void OnCtrlBtnClicked()
{
if (icommand != null)
{
icommand.Execute();
undoFunctions.Push(icommand.UnDo);
}
}
/// <summary>
/// 撤銷
/// </summary>
private void OnUnDoBtnClicked()
{
if (undoFunctions.Count > 0)
{
undoFunctions.Pop().Invoke();
}
}
}
三、配製加載器
public class RemoteLoader : MonoBehaviour
{
public Button lastBtn;
public Button nextBtn;
private int index;
private const int NUM_COMMAND = 10;
private ICommand[] commands;
private string[] textinfos;
private MoveCommand movexCmd;
private MoveCommand moveyCmd;
private MoveCommand movezCmd;
private RotateCommand rotxCmd;
private RotateCommand rotyCmd;
private RotateCommand rotzCmd;
private ColorChangeCommand redColorCmd;
private ColorChangeCommand greenColorCmd;
private ColorChangeCommand blueColorCmd;
private TextChangeCommand textCmd;
private string[] infos = { "A","B", "C", "D", "E", "F" };
public RemoteControl remoteCtrl;
public GameObject cube;
void Awake()
{
lastBtn.onClick.AddListener(OnLastBtnClicked);
nextBtn.onClick.AddListener(OnNextBtnClicked);
}
void Start()
{
commands = new ICommand[NUM_COMMAND];
textinfos = new string[NUM_COMMAND];
textinfos[0] = "x方向移動";
commands[0] = new MoveCommand(cube.transform, Vector3.right);
textinfos[1] = "y方向移動";
commands[1] = new MoveCommand(cube.transform, Vector3.up);
textinfos[2] = "z方向移動";
commands[2] = new MoveCommand(cube.transform, Vector3.forward);
textinfos[3] = "x軸旋轉10度";
commands[3] = new RotateCommand(cube.transform, Vector3.right * 10);
textinfos[4] = "y軸旋轉10度";
commands[4] = new RotateCommand(cube.transform, Vector3.up * 10);
textinfos[5] = "z軸旋轉10度";
commands[5] = new RotateCommand(cube.transform, Vector3.forward * 10);
textinfos[6] = "變紅";
commands[6] = new ColorChangeCommand(Color.red, cube.GetComponent<Renderer>().material);
textinfos[7] = "變綠";
commands[7] = new ColorChangeCommand(Color.green, cube.GetComponent<Renderer>().material);
textinfos[8] = "變藍";
commands[8] = new ColorChangeCommand(Color.blue, cube.GetComponent<Renderer>().material);
textinfos[9] = "換信息";
commands[9] = new TextChangeCommand(cube.GetComponentInChildren<TextMesh>(), infos);
}
private void OnNextBtnClicked()
{
if (index == NUM_COMMAND || index == -1)
{
index = 0;
}
remoteCtrl.SetCommond(commands[index]);
remoteCtrl.SetText(textinfos[index]);
index++;
}
private void OnLastBtnClicked()
{
if (index == NUM_COMMAND || index == -1)
{
index = NUM_COMMAND - 1;
}
remoteCtrl.SetCommond(commands[index]);
remoteCtrl.SetText(textinfos[index]);
index--;
}
}
四、顏色轉換命令腳本
public class ColorChangeCommand : ICommand
{
private Stack<Color> m_OriginColor = new Stack<Color>();
private Color m_Color;
private Material m_Material;
public ColorChangeCommand(Color color, Material material)
{
m_Color = color;
m_Material = material;
}
public void Execute()
{
m_OriginColor.Push(m_Material.color);
m_Material.color = m_Color;
}
public void UnDo()
{
m_Material.color = m_OriginColor.Pop();
}
}
五、移動命令腳本
public class MoveCommand : ICommand
{
private Vector3 m_Offset;
private Transform m_Object;
public MoveCommand(Transform obj, Vector3 offset)
{
this.m_Object = obj;
this.m_Offset = offset;
}
public void Execute()
{
m_Object.transform.position += m_Offset;
}
public void UnDo()
{
m_Object.transform.position -= m_Offset;
}
}
六、轉換命令腳本
public class RemoteControl : MonoBehaviour {
public Button ctrlBtn;
public Button undoBtn;
public Text ctrlName;
private ICommand icommand;
public Stack<UnityAction> undoFunctions = new Stack<UnityAction>();
void Awake(){
ctrlBtn.onClick.AddListener(OnCtrlBtnClicked);
undoBtn.onClick.AddListener(OnUnDoBtnClicked);
}
public void SetText(string textinfo)
{
ctrlName.text = textinfo;
}
public void SetCommond(ICommand icommand)
{
this.icommand = icommand;
}
/// <summary>
/// 執行
/// </summary>
public void OnCtrlBtnClicked()
{
if (icommand != null)
{
icommand.Execute();
undoFunctions.Push(icommand.UnDo);
}
}
/// <summary>
/// 撤銷
/// </summary>
private void OnUnDoBtnClicked()
{
if (undoFunctions.Count > 0)
{
undoFunctions.Pop().Invoke();
}
}
}
七、文字加載腳本
public class TextChangeCommand : ICommand
{
private Stack<string> lastInfos = new Stack<string>();
private IEnumerator<string> datas;
private TextMesh m_Textmesh;
public TextChangeCommand(TextMesh textMesh,ICollection<string> texts)
{
datas = texts.GetEnumerator();
m_Textmesh = textMesh;
}
public void Execute()
{
if (!datas.MoveNext())
{
datas.Reset();
datas.MoveNext();
}
lastInfos.Push(m_Textmesh.text);
m_Textmesh.text = datas.Current;
}
public void UnDo()
{
m_Textmesh.text = lastInfos.Pop();
}
}
僅供參考,謝謝閱讀