编队系统重置 选角页面基本完成 等待存入playerprefs

Assets/scripts/utils/DragGhost.cs

@@ -0,0 +1,50 @@
+using UnityEngine;
+using UnityEngine.UI;
+
+namespace Utils
+{
+    public static class DragGhost
+    {
+        private static GameObject ghost;
+        private static Image ghostImage;
+        private static Canvas parentCanvas;
+
+        // Ensure ghost exists under given canvas
+        public static void Show(Canvas canvas, Sprite sprite)
+        {
+            if (canvas == null || sprite == null) return;
+            if (ghost == null || parentCanvas != canvas)
+            {
+                if (ghost != null) Object.Destroy(ghost);
+                parentCanvas = canvas;
+                ghost = new GameObject("_SharedDragGhost");
+                ghost.transform.SetParent(parentCanvas.transform, false);
+                ghostImage = ghost.AddComponent<Image>();
+                ghostImage.raycastTarget = false;
+                var cg = ghost.AddComponent<CanvasGroup>();
+                cg.blocksRaycasts = false;
+            }
+            ghostImage.sprite = sprite;
+            // set size to sprite rect (avoid SetNativeSize to reduce layout work)
+            var rt = ghostImage.rectTransform;
+            rt.sizeDelta = new Vector2(sprite.rect.width, sprite.rect.height);
+            ghost.SetActive(true);
+        }
+
+        public static void Hide()
+        {
+            if (ghost != null) ghost.SetActive(false);
+        }
+
+        public static void UpdatePosition(Vector2 screenPosition, Camera cam)
+        {
+            if (ghost == null || parentCanvas == null) return;
+            RectTransformUtility.ScreenPointToLocalPointInRectangle(
+                parentCanvas.transform as RectTransform,
+                screenPosition,
+                cam,
+                out Vector2 localPoint);
+            ghost.transform.localPosition = localPoint;
+        }
+    }
+}

Assets/scripts/utils/DragGhost.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 9937514c93fcd0548bac60d489d9b0cc