在新手引导每一步中实现可以遮掉其他部分而显示当前需要点击的部分，只需要在每一步引导的时候设置对应的镂空区域的RectTransform.效果如下图：

代码：

public class SelfMaskSet : MaskableGraphic, ICanvasRaycastFilter
{[SerializeField]public RectTransform _target;private Vector3 _targetMin = Vector3.zero;private Vector3 _targetMax = Vector3.zero;private bool _canRefresh = true;private Transform _cacheTrans = null;/// <summary>/// 设置镂空的目标/// </summary>public void SetTarget(RectTransform target){_canRefresh = true;_target = target;_RefreshView();}private void _SetTarget(Vector3 tarMin, Vector3 tarMax){if (tarMin == _targetMin && tarMax == _targetMax)return;_targetMin = tarMin;_targetMax = tarMax;SetAllDirty();}private void _RefreshView(){if (!_canRefresh) return;_canRefresh = false;if (null == _target){_SetTarget(Vector3.zero, Vector3.zero);SetAllDirty();}else{Bounds bounds = RectTransformUtility.CalculateRelativeRectTransformBounds(_cacheTrans, _target);_SetTarget(bounds.min, bounds.max);}}protected override void OnPopulateMesh(VertexHelper vh){if (_targetMin == Vector3.zero && _targetMax == Vector3.zero){base.OnPopulateMesh(vh);return;}vh.Clear();// 填充顶点UIVertex vert = UIVertex.simpleVert;vert.color = color;Vector2 selfPiovt = rectTransform.pivot;Rect selfRect = rectTransform.rect;float outerLx = -selfPiovt.x * selfRect.width;float outerBy = -selfPiovt.y * selfRect.height;float outerRx = (1 - selfPiovt.x) * selfRect.width;float outerTy = (1 - selfPiovt.y) * selfRect.height;// 0 - Outer:LTvert.position = new Vector3(outerLx, outerTy);vh.AddVert(vert);// 1 - Outer:RTvert.position = new Vector3(outerRx, outerTy);vh.AddVert(vert);// 2 - Outer:RBvert.position = new Vector3(outerRx, outerBy);vh.AddVert(vert);// 3 - Outer:LBvert.position = new Vector3(outerLx, outerBy);vh.AddVert(vert);// 4 - Inner:LTvert.position = new Vector3(_targetMin.x-10, _targetMax.y +10);vh.AddVert(vert);// 5 - Inner:RTvert.position = new Vector3(_targetMax.x + 10, _targetMax.y + 10);vh.AddVert(vert);// 6 - Inner:RBvert.position = new Vector3(_targetMax.x +10, _targetMin.y -10);vh.AddVert(vert);// 7 - Inner:LBvert.position = new Vector3(_targetMin.x -10, _targetMin.y-10);vh.AddVert(vert);// 设定三角形vh.AddTriangle(4, 0, 1);vh.AddTriangle(4, 1, 5);vh.AddTriangle(5, 1, 2);vh.AddTriangle(5, 2, 6);vh.AddTriangle(6, 2, 3);vh.AddTriangle(6, 3, 7);vh.AddTriangle(7, 3, 0);vh.AddTriangle(7, 0, 4);}bool ICanvasRaycastFilter.IsRaycastLocationValid(Vector2 screenPos, Camera eventCamera){if (null == _target) return true;// 将目标对象范围内的事件镂空（使其穿过）return !RectTransformUtility.RectangleContainsScreenPoint(_target, screenPos, eventCamera);}protected override void Awake(){base.Awake();_cacheTrans = GetComponent<RectTransform>();}void Update(){_canRefresh = true;_RefreshView();}public void OnButtonClick() {Debug.Log("测试镂空区域！");}
}