Question

JavaScript => static function OverlapCircle(point: Vector2, radius: float, layerMask: int = DefaultRaycastLayers, minDepth: float = -Mathf.Infinity, maxDepth: float = Mathf.Infinity): Collider2D;
C# => static Collider2D OverlapCircle(Vector2 point, float radius, int layerMask = DefaultRaycastLayers, float minDepth = -Mathf.Infinity, float maxDepth = Mathf.Infinity);

Parameters 参数

point	Centre of the circle. 圆的中心点。
radius	Radius of the circle. 圆的半径。
layerMask	Filter to detect Colliders only on certain layers. 只在某些层过滤检测碰撞器。
minDepth	Only include objects with a Z coordinate (depth) greater than this value. 只包括Z坐标(深度)大于这个值的对象。
maxDepth	Only include objects with a Z coordinate (depth) less than this value. 只包括Z坐标(深度)小于这个值的对象。

Description 描述

Check if a collider falls within a circular area.
检测一个碰撞器是否与落在一个圆形区域（里面）。

The circle is defined by its centre coordinate in world space and by its radius. The optional layerMask allows the test to check only for objects on specific layers.
圆形是由一个在世界空间中的中心点和它的半径定义出来的。层遮罩可以用于指定检测特定某些图层的对象。

Although the Z axis is not relevant for rendering or collisions in 2D, you can use the minDepth and maxDepth parameters to filter objects based on their Z coordinate. If more than one collider falls within the circle then the one returned will be the one with the lowest Z coordinate value. Null is returned if there are no colliders in the circle.
虽然Z轴与2D的渲染或碰撞无关，但是你可以使用minDepth和maxDepth参数去排除一些对象基于他们的Z轴。如果有好几个碰撞器都落在（重叠）检测区域，那么最小的Z坐标的那个碰撞器将会被返回。如果没有碰撞器在区域中就返回Null了。

Note that this function will allocate memory for the returned Collider2D object. You can use OverlapCircleNonAlloc to avoid this overhead if you need to make the check frequently.
还要注意这个函数会分配内存给返回的Collider2D对象。在你需要频繁做这个检测的时候，可以使用OverlapCircleNonAlloc这个函数去避免这些开销。

See Also: OverlapArea, OverlapPoint, OverlapCircleAll, OverlapCircleNonAlloc.