1 需求描述
- 点选物体：点击物体，可以选中物体，按住 Ctrl 追加选中，选中的物体设置为红色。
- 框选物体：拖拽鼠标，屏幕上会出现滑动框，滑动框内的物体会被选中，选中的物体设置为红色。
- 绘制外边框：给选中的物体绘制外边框（选中框）。
滑动框效果如下：
选中边框效果如下：
本文完整代码见→ Unity3D点选物体、框选物体、绘制外边框。
2 需求实现
2.1 场景搭建
1）场景对象
说明：Plane 的 Layer 设置为 Plane (值为 6)。
2）滑动框
拖拽鼠标时，屏幕上会出现滑动框。SlideBox 对象用于显示滑动框，其 Image 组件中，Color 设置为红色，去掉 Raycast Target 勾选；RectTransform 组件中，Pivot 设置为 (0, 0)，Width、Height 都设置为 0。参数设置如下:
2）选框
选中物体后，选中的物体边界会显示外边框（选框）。SelectBox 对象用于显示选框，其 Image 组件中，Source Image 设置为黄色外框 Sprite，去掉 Raycast Target 勾选，ImageType 设置为 Sliced；RectTransform 组件中，Pivot 设置为 (0, 0)，Width、Height 都设置为 0。参数设置如下：
外框图片如下：
说明：外框图片是 png 格式，并且除了黄色边角，其他部分都是透明的，图片导入 Unity 后，需要修改 Texture Type 为 Sprite，并且需要在 Sprite Editor 中 编辑 border（九宫格格式），如下：
2.2 代码
EventDetector.cs
using UnityEngine;
public class EventDetector : MonoBehaviour { // 事件检测器
private MyEventType eventType = MyEventType.None; // 事件类型
private MyEventType lastEventType = MyEventType.None; // 上次事件类型
private float scroll; // 滑轮滑动刻度
private bool detecting; // 事件检测中
private Vector3 clickDownMousePos; // 鼠标按下时的坐标
private const float dragThreshold = 1; // 识别为拖拽的鼠标偏移
private void Awake() {
RectPainter.GetInstance();
}
private void Update() {
detecting = true;
DetectMouseEvent();
DetectScrollEvent();
UpgradeMouseEvent();
detecting = false;
lastEventType = eventType;
}
private void DetectMouseEvent() { // 检测鼠标事件
if (Input.GetMouseButtonDown(0)) { // Click Down
eventType = MyEventType.ClickDown;
clickDownMousePos = Input.mousePosition;
} else if (Input.GetMouseButtonUp(0)) {
if (IsDragEvent(eventType)) { // End Drag
eventType = MyEventType.EndDrag;
} else { // Click Up
eventType = MyEventType.ClickUp;
}
} else if (Input.GetMouseButton(0)) {
if (IsDragEvent(eventType)) { // Drag
eventType = MyEventType.Drag;
} else if (Vector3.Distance(clickDownMousePos, Input.mousePosition) > dragThreshold) { // Begin Drag
eventType = MyEventType.BeginDrag;
} else { // Click
eventType = MyEventType.Click;
}
} else {
eventType = MyEventType.None;
}
}
private void DetectScrollEvent() { // 检测滑轮事件
if (eventType != MyEventType.None
&& (!IsBeginEvent(eventType) || lastEventType != MyEventType.None && !IsScrollEvent(lastEventType))) {
scroll = 0;
return;
}
float temScroll = Input.GetAxis("Mouse ScrollWheel");
if (Mathf.Abs(scroll) < float.Epsilon && Mathf.Abs(temScroll) > float.Epsilon) { // Begin Scroll
eventType = MyEventType.BeginScroll;
scroll = temScroll;
} else if (Mathf.Abs(scroll) > float.Epsilon && Mathf.Abs(temScroll) < float.Epsilon) { // End Scroll
eventType = MyEventType.EndScroll;
scroll = temScroll;
} else if (Mathf.Abs(temScroll) > float.Epsilon) { // Scroll
eventType = MyEventType.Scroll;
scroll = temScroll;
} else {
scroll = 0;
}
}
private void UpgradeMouseEvent() { // 升级鼠标事件(关联键盘事件)
if (eventType == MyEventType.None) {
return;
}
if (IsBeginEvent(eventType)) {
if (Input.GetKey(KeyCode.LeftControl) || Input.GetKey(KeyCode.RightControl)) {
AddKeyType("Ctrl");
} else if (Input.GetKey(KeyCode.LeftAlt) || Input.GetKey(KeyCode.RightAlt)) {
AddKeyType("Alt");
}
} else {
ContinueKeyType(); // 保持按键事件
}
}
public MyEventType EventType() { // 事件类型
if (detecting) {
return lastEventType;
}
return eventType;
}
public bool HasClickEvent() { // 是否有点击事件
MyEventType type = EventType();
return IsClickEvent(type);
}
public bool HasDragEvent() { // 是否有拖拽事件
MyEventType type = EventType();
return IsDragEvent(type);
}
public bool HasScrollEvent() { // 是否有滑轮事件
MyEventType type = EventType();
return IsScrollEvent(type);
}
public bool IsBeginDrag() { // 是否是开始拖拽类型事件
MyEventType type = EventType();
return type == MyEventType.BeginDrag || type == MyEventType.BeginCtrlDrag || type == MyEventType.BeginAltDrag;
}
public float Scroll() { // 鼠标滑轮滑动刻度
if (HasScrollEvent()) {
return scroll;
}
return 0;
}
private bool IsClickEvent(MyEventType type) { // 是否是点击事件
return type >= MyEventType.ClickDown && type <= MyEventType.CtrlClickUp;
}
private bool IsDragEvent(MyEventType type) { // 是否是拖拽事件
return type >= MyEventType.BeginDrag && type <= MyEventType.EndAltDrag;
}
private bool IsScrollEvent(MyEventType type) { // 是否是滑轮事件
return type >= MyEventType.BeginScroll && type <= MyEventType.EndCtrlScroll;
}
private bool IsBeginEvent(MyEventType type) { // 是否是开始类型事件
return type == MyEventType.ClickDown
|| type == MyEventType.BeginDrag
|| type == MyEventType.BeginCtrlDrag
|| type == MyEventType.BeginAltDrag
|| type == MyEventType.BeginScroll
|| type == MyEventType.BeginCtrlScroll;
}
private bool HasCtrlKey(MyEventType type) { // 是否有Ctrl按键事件
return type >= MyEventType.CtrlClickDown && type <= MyEventType.CtrlClickUp
|| type >= MyEventType.BeginCtrlDrag && type <= MyEventType.EndCtrlDrag
|| type >= MyEventType.BeginCtrlScroll && type <= MyEventType.EndCtrlScroll;
}
private bool HasAltKey(MyEventType type) { // 是否有Alt按键事件
return type >= MyEventType.BeginAltDrag && type <= MyEventType.EndAltDrag;
}
private void ContinueKeyType() { // 保持按键事件
if (HasCtrlKey(lastEventType)) {
AddKeyType("Ctrl");
} else if (HasAltKey(lastEventType)) {
AddKeyType("Alt");
}
}
private void AddKeyType(string key) { // 添加按键事件
if ("Ctrl".Equals(key)) {
if (eventType == MyEventType.ClickDown) { // 点击事件
eventType = MyEventType.CtrlClickDown;
} else if (eventType == MyEventType.Click) {
eventType = MyEventType.CtrlClick;
} else if (eventType == MyEventType.ClickUp) {
eventType = MyEventType.CtrlClickUp;
} else if (eventType == MyEventType.BeginDrag) { // 拖拽事件
eventType = MyEventType.BeginCtrlDrag;
} else if (eventType == MyEventType.Drag) {
eventType = MyEventType.CtrlDrag;
} else if (eventType == MyEventType.EndDrag) {
eventType = MyEventType.EndCtrlDrag;
} else if (eventType == MyEventType.BeginScroll) { // 滑轮事件
eventType = MyEventType.BeginCtrlScroll;
} else if (eventType == MyEventType.Scroll) {
eventType = MyEventType.CtrlScroll;
} else if (eventType == MyEventType.EndScroll) {
eventType = MyEventType.EndCtrlScroll;
}
} else if ("Alt".Equals(key)) {
if (eventType == MyEventType.BeginDrag) { // 拖拽事件
eventType = MyEventType.BeginAltDrag;
} else if (eventType == MyEventType.Drag) {
eventType = MyEventType.AltDrag;
} else if (eventType == MyEventType.EndDrag) {
eventType = MyEventType.EndAltDrag;
}
}
}
}
public enum MyEventType { // 事件类型
None = 0,
ClickDown = 1,
Click = 2,
ClickUp = 3,
CtrlClickDown = 4,
CtrlClick = 5,
CtrlClickUp = 6,
BeginDrag = 10,
Drag = 11,
EndDrag = 12,
BeginCtrlDrag = 13,
CtrlDrag = 14,
EndCtrlDrag = 15,
BeginAltDrag = 16,
AltDrag = 17,
EndAltDrag = 18,
BeginScroll = 20,
Scroll = 21,
EndScroll = 22,
BeginCtrlScroll = 23,
CtrlScroll = 24,
EndCtrlScroll = 25,
}说明： EventDetector 脚本组件挂在相机下，用于统一管理事件。点选物体（ClickUp / Ctrl + ClickUp）、滑动选框（Drag）、场景变换（Ctrl + Drag / Alt + Drag）都有鼠标事件，这些事件相互冲突，不便于在每个类里都去捕获鼠标和键盘事件，因此需要 EventDetector 统一管理事件。
ClickSelect.cs
using System.Collections.Generic;
using UnityEngine;
public class ClickSelect : MonoBehaviour { // 点选物体
private EventDetector eventDetector; // 鼠标事件检测器
private List<Transform> targets; // 选中的游戏对象
private List<Transform> loseFocus; // 失焦的游戏对象
private RaycastHit hit; // 碰撞信息
private void Awake() {
targets = new List<Transform>();
loseFocus = new List<Transform>();
eventDetector = Camera.main.GetComponent<EventDetector>();
GameObject.Find("Work").GetComponent<SlideSelect>().targetsChangedHandler += SetTargets;
}
private void Update() {
if (eventDetector.EventType() == MyEventType.ClickUp || eventDetector.EventType() == MyEventType.CtrlClickUp) {
Transform hitTrans = GetHitTrans();
if (hitTrans == null || hitTrans.gameObject.layer == LayerMask.NameToLayer("Plane")) { // 未选中物体或点到地面, 全部取消选中
targets.ForEach(obj => loseFocus.Add(obj));
targets.Clear();
}
else if (eventDetector.EventType() == MyEventType.CtrlClickUp) {
if (targets.Contains(hitTrans)) { // Ctrl重复选中, 取消选中
loseFocus.Add(hitTrans);
targets.Remove(hitTrans);
} else { // Ctrl追加选中
targets.Add(hitTrans);
}
} else { // 单选
targets.ForEach(trans => loseFocus.Add(trans));
loseFocus.Remove(hitTrans);
targets.Clear();
targets.Add(hitTrans);
}
UpdateSelectColor();
RectPainter.DrawRect(targets);
}
}
private void UpdateSelectColor() { // 更新选中的物体颜色
foreach(var item in loseFocus) {
item.GetComponent<Renderer>().material.color = Color.gray;
}
foreach(var item in targets) {
item.GetComponent<Renderer>().material.color = Color.red;
}
loseFocus.Clear();
}
private void SetTargets(List<Transform> targets) { // 框选时触发
this.targets.ForEach(trans => loseFocus.Add(trans));
if (targets == null) {
this.targets.Clear();
} else {
this.targets = targets;
this.targets.ForEach(trans => loseFocus.Remove(trans));
}
UpdateSelectColor();
}
private Transform GetHitTrans() { // 获取屏幕射线碰撞的物体
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit)) {
return hit.transform;
}
return null;
}
}说明：ClickSelect 脚本组件挂在 Work 对象下，用于点选物体。
SlideSelect.cs
using System;
using System.Collections.Generic;
using UnityEngine;
public class SlideSelect : MonoBehaviour { // 滑动框选物体
public Action<List<Transform>> targetsChangedHandler; // 框选目标改变时的处理器
private EventDetector eventDetector; // 鼠标事件检测器
private RectTransform slideTrans; // 滑动选框
private Vector3 preMousePos; // 鼠标滑动前的位置
private Transform work; // 需要检测是否被框选的物体根对象
private List<Transform> targets; // 框选的目标对象
private void Awake() {
slideTrans = GameObject.Find("Canvas/SlideBox").GetComponent<RectTransform>();
work = GameObject.Find("Work").transform;
eventDetector = Camera.main.GetComponent<EventDetector>();
}
private void Update() {
if (eventDetector.EventType() == MyEventType.BeginDrag) {
preMousePos = Input.mousePosition;
} else if (eventDetector.EventType() == MyEventType.EndDrag) {
Rect rect = slideTrans.rect;
rect.position = slideTrans.position;
targets = RectPainter.DrawRect(work, rect);
targetsChangedHandler?.Invoke(targets);
ClearRect();
} else if (eventDetector.EventType() == MyEventType.Drag) {
DrawRect();
}
}
private void DrawRect() { // 绘制滑动选框
float minX = Mathf.Min(Input.mousePosition.x, preMousePos.x);
float minY = Mathf.Min(Input.mousePosition.y, preMousePos.y);
slideTrans.position = new Vector3(minX, minY, 0);
Vector3 delta = Input.mousePosition - preMousePos;
slideTrans.sizeDelta = new Vector2(Mathf.Abs(delta.x), Mathf.Abs(delta.y));
}
private void ClearRect() { // 清除滑动选框
slideTrans.sizeDelta = Vector2.zero;
}
}说明：SlideSelect 脚本组件挂在 Work 对象下，用于滑动框选物体。
RectDetector.cs
using System;
using System.Collections.Generic;
using UnityEngine;
public class RectDetector { // 边框检测器
public static Rect GetRect(List<Transform> targets) { // 获取物体的外边框(包含子对象)
if (targets != null && targets.Count > 0) {
Rect[] rects = new Rect[targets.Count];
for (int i = 0; i < targets.Count; i++) {
rects[i] = GetRect(targets[i]);
}
return GetRect(rects);
}
return new Rect();
}
public static Rect GetCurrRect(List<Transform> targets) { // 获取物体的外边框(不包含子对象)
if (targets != null && targets.Count > 0) {
Rect[] rects = new Rect[targets.Count];
for (int i = 0; i < targets.Count; i++) {
rects[i] = GetCurrRect(targets[i]);
}
return GetRect(rects);
}
return new Rect();
}
public static Rect GetRect(Transform transform) { // 获取物体外边框(包含子物体)
Rect rect = GetInitRect();
ForAllChildren(transform, trans => {
Rect rect1 = GetCurrRect(trans);
rect.xMin = Mathf.Min(rect.xMin, rect1.xMin);
rect.yMin = Mathf.Min(rect.yMin, rect1.yMin);
rect.xMax = Mathf.Max(rect.xMax, rect1.xMax);
rect.yMax = Mathf.Max(rect.yMax, rect1.yMax);
});
return rect;
}
public static Rect GetCurrRect(Transform transform) { // 获取物体外边框(不包含子对象)
Rect rect = GetInitRect();
Vector3[] vertices = GetVertices(transform);
if (vertices != null && vertices.Length > 0) {
for (int i = 0; i < vertices.Length; i++) {
Vector3 screenPos = Camera.main.WorldToScreenPoint(vertices[i]);
rect.xMin = Mathf.Min(rect.xMin, screenPos.x);
rect.yMin = Mathf.Min(rect.yMin, screenPos.y);
rect.xMax = Mathf.Max(rect.xMax, screenPos.x);
rect.yMax = Mathf.Max(rect.yMax, screenPos.y);
}
}
return rect;
}
private static Rect GetRect(Rect[] rects) { // 合并一组边框
if (rects == null || rects.Length == 0) {
return new Rect();
}
Rect rect = rects[0];
for (int i = 1; i < rects.Length; i++) {
rect.xMin = Mathf.Min(rect.xMin, rects[i].xMin);
rect.yMin = Mathf.Min(rect.yMin, rects[i].yMin);
rect.xMax = Mathf.Max(rect.xMax, rects[i].xMax);
rect.yMax = Mathf.Max(rect.yMax, rects[i].yMax);
}
return rect;
}
private static Rect GetInitRect() { // 获取初始的边框
Rect rect = new Rect();
rect.xMin = float.MaxValue;
rect.yMin = float.MaxValue;
rect.xMax = float.MinValue;
rect.yMax = float.MinValue;
return rect;
}
private static Vector3[] GetVertices(Transform transform) { // 获取网格顶点的世界坐标
if (transform.GetComponent<MeshFilter>() == null || transform.GetComponent<MeshFilter>().mesh == null) {
return null;
}
Vector3[] vertices = transform.GetComponent<MeshFilter>().mesh.vertices;
for (int i = 0; i < vertices.Length; i++)
{
vertices[i] = transform.TransformPoint(vertices[i]);
}
return vertices;
}
private static void ForAllChildren(Transform transform, Action<Transform> action) { // 对所有子对象执行活动
if (transform == null || action == null) {
return;
}
Transform[] children = transform.GetComponentsInChildren<Transform>();
for(int i = 0; i < children.Length; i++) {
action(children[i]);
}
}
}RectPainter.cs
using System;
using System.Collections.Generic;
using UnityEngine;
public class RectPainter { // 矩形选框渲染器
private const float border = 5; // 矩形选框的边界宽度
private static RectPainter instance; // 单例
private RectTransform selectTrans; // 选框
private List<Transform> targets; // 选中的游戏对象
private RectPainter() {
selectTrans = GameObject.Find("Canvas/SelectBox").transform as RectTransform;
Camera.main.GetComponent<SceneController>().camChangedHandler += DrawRect;
}
public static RectPainter GetInstance() { // 获取单例
if (instance == null) {
instance = new RectPainter();
}
return instance;
}
public static void DrawRect(List<Transform> targets) { // 绘制被选中物体的外边框(包含子对象)
if (instance != null) {
instance.targets = targets;
Rect rect = RectDetector.GetRect(targets);
instance.DrawRect(rect);
}
}
public static void DrawCurrRect(List<Transform> targets) { // 绘制被选中物体的外边框(不包含子对象)
if (instance != null) {
instance.targets = targets;
Rect rect = RectDetector.GetCurrRect(targets);
instance.DrawRect(rect);
}
}
public static List<Transform> DrawRect(Transform root, Rect rect) { // 绘制root下面的在rect内的物体的外边框
if (instance != null) {
instance.targets = new List<Transform>();
ForAllChildren(root, trans => {
Rect rect1 = RectDetector.GetCurrRect(trans);
if (ContainsRect(rect, rect1)) {
instance.targets.Add(trans);
}
});
instance.DrawCurrRect();
return instance.targets;
}
return null;
}
private void DrawRect() { // 绘制边框(包含子对象)
Rect rect = RectDetector.GetRect(targets);
DrawRect(rect);
}
private void DrawCurrRect() { // 绘制边框(不包含子对象)
Rect rect = RectDetector.GetCurrRect(targets);
DrawRect(rect);
}
private void DrawRect(Rect rect) { // 绘制边框
selectTrans.position = new Vector3(rect.x - border, rect.y - border, 0);
selectTrans.sizeDelta = new Vector2(rect.width + border * 2, rect.height + border * 2);
}
private static bool ContainsRect(Rect rect1, Rect rect2) { // 判断rect1是否包含rect2
if (rect1.width <= 0 || rect1.height <= 0 || rect2.width <= 0 || rect2.height <= 0) {
return false;
}
if (rect2.xMin < rect1.xMin || rect2.yMin < rect1.yMin || rect2.xMax > rect1.xMax || rect2.yMax > rect1.yMax) {
return false;
}
return true;
}
private static void ForAllChildren(Transform transform, Action<Transform> action) { // 对所有子对象执行活动
if (transform == null || action == null) {
return;
}
Transform[] children = transform.GetComponentsInChildren<Transform>();
for(int i = 0; i < children.Length; i++) {
action(children[i]);
}
}
}SceneController.cs
using System;
using UnityEngine;
public class SceneController : MonoBehaviour {
private EventDetector eventDetector; // 鼠标事件检测器
public Action camChangedHandler; // 相机改变处理器
private Transform cam; // 相机
private float nearPlan; // 近平面
private Vector3 preMousePos; // 上一帧的鼠标坐标
private void Awake() {
cam = Camera.main.transform;
nearPlan = Camera.main.nearClipPlane;
eventDetector = cam.GetComponent<EventDetector>();
}
private void Update() { // 更新场景(Ctrl+Scroll: 缩放场景, Ctrl+Drag: 平移场景, Alt+Drag: 旋转场景)
if (eventDetector.EventType() == MyEventType.CtrlScroll) { // 缩放场景
ScaleScene(eventDetector.Scroll());
} else if (eventDetector.IsBeginDrag()) {
preMousePos = Input.mousePosition;
} else if (eventDetector.HasDragEvent()) {
Vector3 offset = Input.mousePosition - preMousePos;
if (eventDetector.EventType() == MyEventType.CtrlDrag) { // 移动场景
MoveScene(offset);
} else if (eventDetector.EventType() == MyEventType.AltDrag) { // 旋转场景
RotateScene(offset);
}
preMousePos = Input.mousePosition;
}
}
private void ScaleScene(float scroll) { // 缩放场景
cam.position += cam.forward * scroll;
camChangedHandler?.Invoke();
}
private void MoveScene(Vector3 offset) { // 平移场景
cam.position -= (cam.right * offset.x / 100 + cam.up * offset.y / 100);
camChangedHandler?.Invoke();
}
private void RotateScene(Vector3 offset) { // 旋转场景
Vector3 rotateCenter = GetRotateCenter(0);
cam.RotateAround(rotateCenter, Vector3.up, offset.x / 3); // 水平拖拽分量
cam.LookAt(rotateCenter);
cam.RotateAround(rotateCenter, -cam.right, offset.y / 5); // 竖直拖拽分量
camChangedHandler?.Invoke();
}
private Vector3 GetRotateCenter(float planeY) { // 获取旋转中心
if (Mathf.Abs(cam.forward.y) < Vector3.kEpsilon || Mathf.Abs(cam.position.y) < float.Epsilon)
{
return cam.position + cam.forward * (nearPlan + 1 / nearPlan);
}
float t = (planeY - cam.position.y) / cam.forward.y;
float x = cam.position.x + t * cam.forward.x;
float z = cam.position.z + t * cam.forward.z;
return new Vector3(x, planeY, z);
}
}说明： SceneController 脚本组件挂在相机下，用于平移、旋转、缩放场景，其原理见→缩放、平移、旋转场景。
3 运行效果
