unity不规则按钮解决方案

一种是alpha检测

一种是设置collider

参考：

https://zhuanlan.zhihu.com/p/34204396

下面给出第二种方案代码

1///按钮多边形点击方案，注意Canvas模式应该是Screen Space - Camera  需设置 Render Camera
2///选中按钮右键UI->变更为多边形按钮，编辑子物体的Collider2D即可
3///如果无法编辑Collider 则是Unity编辑器bug 切换下Unity编辑器的布局模式，即可恢复正常
4
5using UnityEngine;
6using UnityEngine.UI;
7#if UNITY_EDITOR
8using UnityEditor;
9#endif
10
11[RequireComponent(typeof(PolygonCollider2D))]
12public class NonRectangularButtonImage : Image
13{
14    private PolygonCollider2D areaPolygon;
15
16    protected NonRectangularButtonImage()
17    {
18        useLegacyMeshGeneration = true;
19    }
20
21    private PolygonCollider2D Polygon
22    {
23        get
24        {
25            if (areaPolygon != null)
26                return areaPolygon;
27
28            areaPolygon = GetComponent<PolygonCollider2D>();
29            return areaPolygon;
30        }
31    }
32
33    protected override void OnPopulateMesh(VertexHelper vh)
34    {
35        vh.Clear();
36    }
37
38    public override bool IsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera)
39    {
40        return Polygon.OverlapPoint(eventCamera.ScreenToWorldPoint(screenPoint));
41    }
42
43#if UNITY_EDITOR
44    protected override void Reset()
45    {
46        base.Reset();
47        transform.localPosition = Vector3.zero;
48        var w = rectTransform.sizeDelta.x * 0.5f + 0.1f;
49        var h = rectTransform.sizeDelta.y * 0.5f + 0.1f;
50        Polygon.points = new[]
51        {
52            new Vector2(-w, -h),
53            new Vector2(w, -h),
54            new Vector2(w, h),
55            new Vector2(-w, h)
56        };
57    }
58#endif
59}
60#if UNITY_EDITOR
61[CustomEditor(typeof(NonRectangularButtonImage), true)]
62public class CustomRaycastFilterInspector : Editor
63{
64    public override void OnInspectorGUI()
65    {
66    }
67}
68
69public class NonRectAngularButtonImageHelper
70{
71    [MenuItem("GameObject/UI/变更为多边形按钮")]
72    public static void CreateNonRectAngularButtonImage()
73    {
74        var goRoot = Selection.activeGameObject;
75        if (goRoot == null)
76            return;
77
78        var button = goRoot.GetComponent<Button>();
79
80        if (button == null)
81        {
82            Debug.Log("Selecting Object is not a button!");
83            return;
84        }
85
86        // 关闭原来button的射线检测
87        var graphics = goRoot.GetComponentsInChildren<Graphic>();
88        foreach (var graphic in graphics)
89        {
90            graphic.raycastTarget = false;
91        }
92
93        var polygon = new GameObject("NonRectangularButtonImage");
94        polygon.AddComponent<PolygonCollider2D>();
95        polygon.AddComponent<NonRectangularButtonImage>();
96        polygon.transform.SetParent(goRoot.transform, false);
97        polygon.transform.SetAsLastSibling();
98        //设置锚点方案，注意rect transfrom的框必须包住多边形，否则超出的部分无效
99        polygon.GetComponent<RectTransform>().SetInsetAndSizeFromParentEdge(RectTransform.Edge.Left, 0, 0);
100        polygon.GetComponent<RectTransform>().SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top, 0, 0);
101        polygon.GetComponent<RectTransform>().SetInsetAndSizeFromParentEdge(RectTransform.Edge.Right, 0, 0);
102        polygon.GetComponent<RectTransform>().SetInsetAndSizeFromParentEdge(RectTransform.Edge.Bottom, 0, 0);
103        polygon.GetComponent<RectTransform>().anchorMin = new Vector2(0, 0);
104        polygon.GetComponent<RectTransform>().anchorMax = new Vector2(1, 1);
105    }
106}
107
108#endif