Is there a way to enable them in gameplay mode?
The purpose of anchors is that they can be edited in the Scene window. You can't edit them in the Game window (like many other editable stuff), so there is no need for them to be visible there. But you can use Gizmos to visualize their positions in the Game window even when the game is not running. To do this add either OnDrawGizmos() or OnDrawGizmosSelected() methods to your MonoBehaviour class. There are various forms of Gizmos visualization available: 
Example:
/// <summary> /// Draw wired cube at `transform.position` of the current object. /// </summary> private void OnDrawGizmos() { float cubeSize = 0.1f; Gizmos.color = Color.white; Gizmos.DrawWireCube(transform.position, Vector3.one * cubeSize); }
In your case, you should add Gizmos.* drawing for each anchor position you want to be visible and replace transform.position with their actual positions. Keep in mind that Gizmos methods accept position and size parameters in world coordinates.
Here is an example of a component class that shows (visualizes with Gizmos) its anchors both in Game and Scene windows:
[DisallowMultipleComponent] public class ShowAnchors : MonoBehaviour { #pragma warning disable CS0649 [SerializeField] private float _gizmosSize = 5f; [SerializeField] private Color _color = Color.white; #pragma warning restore CS0649 private void OnDrawGizmos() { RectTransform rt = transform as RectTransform; if (!rt) return; // the object is not an UI element if (!rt.parent) return; // the object doesn't have a parent Gizmos.color = _color; RectTransform parent = rt.parent as RectTransform; Rect parentRect = parent.rect; Matrix4x4 mat = parent.localToWorldMatrix; Vector2 minPos = parentRect.min + new Vector2(rt.anchorMin.x * parentRect.size.x, rt.anchorMin.y * parentRect.size.y); Vector2 maxPos = parentRect.min + new Vector2(rt.anchorMax.x * parentRect.size.x, rt.anchorMax.y * parentRect.size.y); // Anchor positions in screen coordinates. Vector2[] anchors = new Vector2[4] { minPos, new Vector2(minPos.x, maxPos.y), maxPos, new Vector2(maxPos.x, minPos.y) }; for (int i = 0; i < anchors.Length; i++) { Vector3 anchor = anchors[i]; // convert anchor position from screen to world coordinates Vector3 worldPos = mat.MultiplyPoint(anchor); // make gizmos look the same size for different camera projections & sizes float size = constGizmoSize(worldPos); // draw point Gizmos.DrawSphere(worldPos, size); // draw line Vector3 dir = Vector3.ClampMagnitude(_dirs[i], size * 2); Gizmos.DrawLine(worldPos, worldPos + dir); } } private static readonly Vector3[] _dirs = new Vector3[4] { Vector2.left + Vector2.down, Vector2.left + Vector2.up, Vector2.right + Vector2.up, Vector2.right + Vector2.down, }; private float constGizmoSize(Vector3 position) { Camera camera = Camera.current; if (!camera) return _gizmosSize; position = Gizmos.matrix.MultiplyPoint(position); Transform transform = camera.transform; Vector3 position2 = transform.position; float z = Vector3.Dot(position - position2, transform.TransformDirection(new Vector3(0f, 0f, 1f))); Vector3 a = camera.WorldToScreenPoint(position2 + transform.TransformDirection(new Vector3(0f, 0f, z))); Vector3 b = camera.WorldToScreenPoint(position2 + transform.TransformDirection(new Vector3(1f, 0f, z))); float magnitude = (a - b).magnitude; float size = _gizmosSize / Mathf.Max(magnitude, 0.0001f); return size; } }
Add it to the UI elements and you'll get a picture in the editor like this:
(added to the Button(red) and its child Text(green))
If I move them around dynamically, it would be great if I could preview them moving in the unity editor dynamically.
Could you explain this more clearly?
