2 files changed, 8 insertions, 4 deletions
diff --git a/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutGroup.cs b/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutGroup.cs
index 59d432c..6a17e00 100644
--- a/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutGroup.cs
+++ b/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutGroup.cs
@@ -34,12 +34,13 @@ namespace UnityEngine.UI
         private Vector2 m_TotalFlexibleSize = Vector2.zero;
 
         [System.NonSerialized] private List<RectTransform> m_RectChildren = new List<RectTransform>();
-        protected List<RectTransform> rectChildren { get { return m_RectChildren; } }
-
-        // ILayoutElement Interface
+        protected List<RectTransform> rectChildren { get { return m_RectChildren; } }
+
+
+        // ILayoutElement Interface
+        // 收集子节点中参与布局的节点
         public virtual void CalculateLayoutInputHorizontal()
         {
-            // 收集子节点中参与layout的节点
             m_RectChildren.Clear();
             var toIgnoreList = ListPool<Component>.Get();
             for (int i = 0; i < rectTransform.childCount; i++)
diff --git a/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutRebuilder.cs b/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutRebuilder.cs
index 6edd5b5..5fba1cc 100644
--- a/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutRebuilder.cs
+++ b/Assets/uGUI-2017.1/UnityEngine.UI/UI/Core/Layout/LayoutRebuilder.cs
@@ -78,6 +78,7 @@ namespace UnityEngine.UI
             }
         }
 
+        // 从上到下遍历，执行action
         private void PerformLayoutControl(RectTransform rect, UnityAction<Component> action)
         {
             if (rect == null)
@@ -96,6 +97,8 @@ namespace UnityEngine.UI
                 // Layout control needs to executed top down with parents being done before their children,
                 // because the children rely on the sizes of the parents.
 
+                // 做两次遍历，先执行ILayoutSelfController比如ContentSizeFitter，再执行ILayoutGroup
+
                 // First call layout controllers that may change their own RectTransform
                 for (int i = 0; i < components.Count; i++)
                     if (components[i] is ILayoutSelfController)