Unity 进阶之简单模仿鼠标交互（场景：手机屏幕当做触摸板Touch Pad，移动鼠标，鼠标确定等操作）

一、简单介绍

二、实现原理

三、注意事项

四、效果预览

五、实现步骤

六、关键代码

一、简单介绍

Unity中的一些知识点整理。

本节简单介绍在Unity开发中的，因为项目的开发需要，需要把手机屏幕当做触控板，模拟鼠标移动和点击交互等，所以这里简单的整理一些，或许场景不同，你可能需要进行屏幕适配，这里仅供参考学习使用，如果你有新的方式也可以留言，多谢。

二、实现原理

1、这里使用 Input.GetMouseButtonDown(0) 、Input.GetMouseButton(0) 、Input.GetMouseButtonUp(0) 相关事件来获取位置相关信息进行处理，用来当做UI射线交互的位置

2、获取当前的 UI 的 EventSystem，然后进行对应改写，关键代码如下

m_eventSystem = EventSystem.current; // 获取当前的 EventSystem
m_pointerEvent = new PointerEventData(m_eventSystem);
m_pointerEvent.button = PointerEventData.InputButton.Left;

m_pointerEvent.position = mFunPointerPos != null ? mFunPointerPos.Invoke() : new Vector2(Screen.width * 1 / 2, Screen.height / 2); // 这里就是模拟鼠标位置

List<RaycastResult> raycastResults = new List<RaycastResult>();
m_eventSystem.RaycastAll(m_pointerEvent, raycastResults);

三、注意事项

1、使用场景不同，可能需要做适当的屏幕适配

2、因为使用模拟鼠标交互，EventSystem 上默认的 Standalone Input Module 最好移除或者禁用，不然可能影响模拟的鼠标交互操作

3、可能有些情况模拟的鼠标会被遮住，你可以进行对应处理，可以调整UI层级，可以换种方式显示模拟鼠标，可以添加材质调整渲染队列，等

四、效果预览

五、实现步骤

1、打开 Unity ，新建空工程

2、布置场景，一个是模拟的鼠标点，一些事交互控件

3、创建脚本，编写对应的逻辑代码，实现对应功能，IMouseGesturePointerCallback 回调接口，MousePointerMoveWrapper 鼠标位置，ScreenRayRaycasterUIWrapper 获取改写EventSystem当前的UI交互等等

4、把脚本挂载到场景中，并对应把模拟的鼠标赋值，如图

5、这里Button 设置如下，并挂载一个脚本，用来点击交互，计数使用，方便效果演示

6、EventSystem 上默认的 Standalone Input Module 最好移除或者禁用，不然可能影响模拟的鼠标交互操作

7、运行场景，点击屏幕，移动，就可看到对应鼠标移动，并能简单交互，效果如上

六、关键代码

1、TestMousePointerInteraction

using System.Collections;
using System.Collections.Generic;
using UnityEngine;namespace XANUtil { public class TestMousePointerInteraction : MonoBehaviour,IMouseGesturePointerCallback{public RectTransform PointerImageRectTrans;private MousePointerMoveWrapper mMousePointerMoveWrapper = new MousePointerMoveWrapper();private ScreenRayRaycasterUIWrapper mScreenRayRaycasterUIWrapper = new ScreenRayRaycasterUIWrapper();void Start(){Init();}void Update(){if (mMousePointerMoveWrapper != null){mMousePointerMoveWrapper.Update();}if (mScreenRayRaycasterUIWrapper != null){mScreenRayRaycasterUIWrapper.Update();}}void Init(){if (mMousePointerMoveWrapper != null){// 把鼠标的位置传 Ray 发射位置mMousePointerMoveWrapper.Init(this);}if (mScreenRayRaycasterUIWrapper != null){// 把鼠标的位置传 Ray 发射位置mScreenRayRaycasterUIWrapper.Init(() => { return PointerImageRectTrans.anchoredPosition; });}}#region PointerImageRectTransvoid SetPointerImageRectTrans(Vector2 deltrPos){if (PointerImageRectTrans != null){Vector2 val = PointerImageRectTrans.anchoredPosition;val += ModifyPointerPos(deltrPos);PointerImageRectTrans.anchoredPosition = ClampValue(val);}}/// <summary>/// 根据需要做指针位置修正处理/// </summary>/// <param name="deltrPos"></param>/// <returns></returns>Vector2 ModifyPointerPos(Vector2 deltrPos){return deltrPos;}/// <summary>/// 显示指针位置/// </summary>/// <param name="val"></param>/// <returns></returns>Vector2 ClampValue(Vector2 val){val.x = val.x < 0 ? 0 : val.x;val.y = val.y < 0 ? 0 : val.y;val.x = val.x > Screen.width ? Screen.width : val.x;val.y = val.y > Screen.height ? Screen.height : val.y;return val;}#endregion#region Interface IMouseGesturePointerCallbackpublic void MousePointerMoveDeltraPos(Vector2 deltraPos){SetPointerImageRectTrans(deltraPos);}#endregion}
}

2、SimulationPointerButtonItem

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;namespace XANUtil { /// <summary>/// 简单的模拟指针选中的按钮脚本/// （可以不用这个，也可重写，仅做参考）/// </summary>public class SimulationPointerButtonItem : MonoBehaviour{private Button mBtn;private Text mBtnText;Action mOnClick;private int mCounter = 0;private void Awake(){Init(null);}public void Init(Action onClick){mBtn = this.GetComponent<Button>();mBtnText = this.GetComponentInChildren<Text>();mCounter = 0;mOnClick = onClick;mBtn.onClick.AddListener(OnClick);}public void OnClick(){mCounter++;mBtnText.text = mCounter.ToString();mOnClick?.Invoke();}}
}

3、ScreenRayRaycasterUIWrapper

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;namespace XANUtil { public class ScreenRayRaycasterUIWrapper {// Prevents loop over the same selectableSelectable m_excluded;Selectable m_currentSelectable = null;RaycastResult m_currentRaycastResult;IPointerClickHandler m_clickHandler;IDragHandler m_dragHandler;EventSystem m_eventSystem;PointerEventData m_pointerEvent;Func<Vector2> mFunPointerPos;private bool mIsClick = false;private bool mIsSwipe = false;private bool mIsDrag = false;private Vector2 oldPos;private Vector2 lastPos;private const float MOVE_LENGTH_LIMIT = 10;public void Init(Func<Vector2> funPointerPos){m_eventSystem = EventSystem.current;m_pointerEvent = new PointerEventData(m_eventSystem);m_pointerEvent.button = PointerEventData.InputButton.Left;mFunPointerPos = funPointerPos;}public void Update(){// 没有数据屏幕中心（即为 width * 3/4，height * 1/2）// Set pointer positionm_pointerEvent.position = mFunPointerPos != null ? mFunPointerPos.Invoke() : new Vector2(Screen.width * 1 / 2, Screen.height / 2);List<RaycastResult> raycastResults = new List<RaycastResult>();m_eventSystem.RaycastAll(m_pointerEvent, raycastResults);// Detect selectableif (raycastResults.Count > 0){foreach (var result in raycastResults){var newSelectable = result.gameObject.GetComponentInParent<Selectable>();if (newSelectable){if (newSelectable != m_excluded && newSelectable != m_currentSelectable){Select(newSelectable);m_currentRaycastResult = result;}break;}}}else{if (m_currentSelectable || m_excluded){Select(null, null);}}// Target is being activatingif (m_currentSelectable){if (m_clickHandler != null && Input.GetMouseButtonUp(0) && mIsSwipe == false){m_clickHandler.OnPointerClick(m_pointerEvent);Select(null, null);}else if (m_dragHandler != null && mIsClick /*&& mIsSwipe == false*/){mIsDrag = true;m_pointerEvent.pointerPressRaycast = m_currentRaycastResult;m_dragHandler.OnDrag(m_pointerEvent);}if (m_dragHandler == null){mIsClick = false;mIsSwipe = false;}if (m_clickHandler != null || m_dragHandler != null){if (Input.GetMouseButtonDown(0)){oldPos = Input.mousePosition;mIsClick = true;}else if (Input.GetMouseButtonUp(0)){mIsSwipe = false;mIsClick = false;mIsDrag = false;Select(null, null);}else{lastPos = Input.mousePosition;mIsSwipe = JudgeISSwipe(oldPos, lastPos);}}}else{mIsClick = false;mIsSwipe = false;Select(null, null);}if (Input.GetMouseButtonUp(0)){mIsSwipe = false;mIsClick = false;mIsDrag = false;Select(null, null);}}/// <summary>/// 判断是否是缓动/// </summary>/// <param name="oldPos"></param>/// <param name="lastPos"></param>/// <returns></returns>private bool JudgeISSwipe(Vector2 oldPos, Vector2 lastPos){return Vector3.Distance(oldPos, lastPos) > MOVE_LENGTH_LIMIT;}/// <summary>/// 选择操作/// </summary>/// <param name="s"></param>/// <param name="exclude"></param>void Select(Selectable s, Selectable exclude = null){if (mIsDrag == true){return;}m_excluded = exclude;if (m_currentSelectable)m_currentSelectable.OnPointerExit(m_pointerEvent);m_currentSelectable = s;if (m_currentSelectable){m_currentSelectable.OnPointerEnter(m_pointerEvent);m_clickHandler = m_currentSelectable.GetComponent<IPointerClickHandler>();m_dragHandler = m_currentSelectable.GetComponent<IDragHandler>();}else{m_clickHandler = null;m_dragHandler = null;}}}
}

4、MousePointerMoveWrapper

using System.Collections;
using System.Collections.Generic;
using UnityEngine;namespace XANUtil { public class MousePointerMoveWrapper{private Vector2 mOldPos;private Vector2 mLastPos;private IMouseGesturePointerCallback mIMouseGesturePointerCallback;public void Init(IMouseGesturePointerCallback callback) {mIMouseGesturePointerCallback = callback;}public void Update(){if (Input.GetMouseButtonDown(0)){mOldPos = Input.mousePosition;}else if (Input.GetMouseButton(0)){mLastPos = Input.mousePosition;Vector2 deltaPosition = (mLastPos - mOldPos);mIMouseGesturePointerCallback?.MousePointerMoveDeltraPos(deltaPosition);mOldPos = mLastPos;}}}
}

5、IMouseGesturePointerCallback

using System.Collections;
using System.Collections.Generic;
using UnityEngine;namespace XANUtil
{ public interface IMouseGesturePointerCallback {void MousePointerMoveDeltraPos(Vector2 deltraPos);}
}