由于UGUI中的Button组件只能添加Click一种事件有一定的局限性，如果我要做当按钮被按下时并且手指不离开屏幕让按钮缩小如果只用Click事件当手指滑动到其他地方后就没办法恢复到按钮原来的大小了。还比如我没还要检测手指在按钮上滑动的距离这时Button组件明显也不满足需求。所以我就根据UGUI中Button组件的源码写了拥有按下、抬起、离开按钮、开始滑动、停止滑动、滑动等事件的组件代码如下：
1 using System;
2
3 using UnityEngine;
4 using UnityEngine.Events;
5 using UnityEngine.EventSystems;
6 using UnityEngine.Serialization;
7 using UnityEngine.UI;
8
9 [AddComponentMenu("UGUIExpend/UITouch", 30)]
10 public class UITouch : Selectable, IBeginDragHandler, IDragHandler, IEndDragHandler
11 {
12 [Serializable]
13 public class TouchEvent : UnityEvent
14 {
15 public PointerEventData eventData = default;
16 }
17
18 [SerializeField]
19 private TouchEvent m_OnTouchDown = new TouchEvent();
20
21 [SerializeField]
22 private TouchEvent m_OnTouchUp = new TouchEvent();
23
24 [SerializeField]
25 private TouchEvent m_OnTouchExit = new TouchEvent();
26
27 [SerializeField]
28 private TouchEvent m_OnBeginSlide = new TouchEvent();
29
30 [SerializeField]
31 private TouchEvent m_OnSlide = new TouchEvent();
32
33 [SerializeField]
34 private TouchEvent m_OnEndSlide = new TouchEvent();
35
36 protected UITouch(){}
37 public TouchEvent OnTouchDown
38 {
39 get { return this.m_OnTouchDown; }
40 set { m_OnTouchDown = value; }
41 }
42
43 public TouchEvent OnTouchUp
44 {
45 get { return this.m_OnTouchUp; }
46 set { this.m_OnTouchUp = value; }
47 }
48
49 public TouchEvent OnTouchExit
50 {
51 get { return m_OnTouchExit; }
52 set { m_OnTouchExit = value; }
53 }
54
55 public TouchEvent OnBeginSlider
56 {
57 get { return m_OnBeginSlide; }
58 set { m_OnBeginSlide = value; }
59 }
60
61 public TouchEvent OnSlider
62 {
63 get { return m_OnSlide; }
64 set { m_OnSlide = value; }
65 }
66 public TouchEvent OnEndSlider
67 {
68 get { return m_OnEndSlide; }
69 set { m_OnEndSlide = value; }
70 }
71
72 private void touchDownOption(PointerEventData eventData)
73 {
74 if(!IsActive() || !IsInteractable())
75 {
76 return;
77 }
78 UISystemProfilerApi.AddMarker("UITouch.OnTouchDown",this);
79 m_OnTouchDown.eventData = eventData;
80 m_OnTouchDown.Invoke();
81 }
82
83 private void touchExitOption(PointerEventData eventData)
84 {
85 if (!IsActive() || !IsInteractable())
86 {
87 return;
88 }
89 UISystemProfilerApi.AddMarker("UITouch.OnTouchExit", this);
90 m_OnTouchExit.eventData = eventData;
91 m_OnTouchExit.Invoke();
92 }
93
94 private void touchUpOption(PointerEventData eventData)
95 {
96 if (!IsActive() || !IsInteractable())
97 {
98 return;
99 }
100 UISystemProfilerApi.AddMarker("UITouch.OnTouchUp", this);
101 m_OnTouchUp.eventData = eventData;
102 m_OnTouchUp.Invoke();
103 }
104
105 private void slideOption(PointerEventData eventData)
106 {
107 if (!IsActive() || !IsInteractable())
108 {
109 return;
110 }
111 UISystemProfilerApi.AddMarker("UITouch.OnSlider", this);
112 m_OnSlide.eventData = eventData;
113 m_OnSlide.Invoke();
114 }
115 private void beginSlideOption(PointerEventData eventData)
116 {
117 if (!IsActive() || !IsInteractable())
118 {
119 return;
120 }
121 UISystemProfilerApi.AddMarker("UITouch.OnSlider", this);
122 m_OnBeginSlide.eventData = eventData;
123 m_OnBeginSlide.Invoke();
124 }
125 private void endSlideOption(PointerEventData eventData)
126 {
127 if (!IsActive() || !IsInteractable())
128 {
129 return;
130 }
131 UISystemProfilerApi.AddMarker("UITouch.OnSlider", this);
132 m_OnEndSlide.eventData = eventData;
133 m_OnEndSlide.Invoke();
134 }
135 public override void OnPointerDown(PointerEventData eventData)
136 {
137 if (eventData.button != PointerEventData.InputButton.Left)
138 {
139 return;
140 }
141 touchDownOption(eventData);
142 }
143 public override void OnPointerUp(PointerEventData eventData)
144 {
145 if(eventData.button != PointerEventData.InputButton.Left)
146 {
147 return;
148 }
149 touchUpOption(eventData);
150 }
151 public override void OnPointerExit(PointerEventData eventData)
152 {
153 if (eventData.button != PointerEventData.InputButton.Left)
154 {
155 return;
156 }
157 touchExitOption(eventData);
158 }
159
160 public void OnBeginDrag(PointerEventData eventData)
161 {
162 if (eventData.button != PointerEventData.InputButton.Left)
163 {
164 return;
165 }
166 beginSlideOption(eventData);
167 //throw new NotImplementedException();
168 }
169
170 public void OnDrag(PointerEventData eventData)
171 {
172 if (eventData.button != PointerEventData.InputButton.Left)
173 {
174 return;
175 }
176 slideOption(eventData);
177 }
178
179 public void OnEndDrag(PointerEventData eventData)
180 {
181 if (eventData.button != PointerEventData.InputButton.Left)
182 {
183 return;
184 }
185 endSlideOption(eventData);
186 }
187 }