uGUI之继承结构

1. UIBehaviour

   继承自MonoBehaviour ，代表ui 组件（区分渲染的ui组件）

   1. 组件流程方法

         //流程方法
           protected virtual void Awake()
           {}
   
           protected virtual void OnEnable()
           {}
   
           protected virtual void Start()
           {}
   
           protected virtual void OnDisable()
           {}
   
           protected virtual void OnDestroy()
           {}

   2. ui 组件结构变动回调函数

            protected virtual void OnRectTransformDimensionsChange()
              {}
      
              protected virtual void OnBeforeTransformParentChanged()
              {}
      
              protected virtual void OnTransformParentChanged()
              {}
      
              protected virtual void OnDidApplyAnimationProperties()
              {}
      
              protected virtual void OnCanvasGroupChanged()
              {}
      
              /// <summary>
              /// Called when the state of the parent Canvas is changed.
              /// </summary>
              protected virtual void OnCanvasHierarchyChanged()
              {}

   3. 添加 IsActive 方法

         /// <summary>
           /// Returns true if the GameObject and the Component are active. 
           /// isActiveAndEnabled 变量存在于 Behaviour中，组件都有的两个变量，命名规则 isxx 都是只读变量 
           /// 1. enabled  2. isActiveAndEnabled
           /// </summary>
           public virtual bool IsActive()
           {
               return isActiveAndEnabled;
           }

   4. 添加 IsDestory 方法（todo）

              /// <summary>
              /// Returns true if the native representation of the behaviour has been destroyed.
              /// </summary>
              /// <remarks>
              /// When a parent canvas is either enabled, disabled or a nested canvas's OverrideSorting is changed this function is called. You can for example use this to modify objects below a canvas that may depend on a parent canvas - for example, if a canvas is disabled you may want to halt some processing of a UI element.
              /// </remarks>
              public bool IsDestroyed()
              {
                  // Workaround for Unity native side of the object
                  // having been destroyed but accessing via interface
                  // won't call the overloaded ==
                  return this == null;
              }

   5. 完整代码

        public abstract class UIBehaviour : MonoBehaviour
       {
           //流程方法
           protected virtual void Awake()
           {}
   
           protected virtual void OnEnable()
           {}
   
           protected virtual void Start()
           {}
   
           protected virtual void OnDisable()
           {}
   
           protected virtual void OnDestroy()
           {}
   
           /// <summary>
           /// Returns true if the GameObject and the Component are active. 
           /// isActiveAndEnabled 变量存在于 Behaviour中，组件都有的两个变量，命名规则 isxx 都是只读变量 
           /// 1. enabled  2. isActiveAndEnabled
           /// </summary>
           public virtual bool IsActive()
           {
               return isActiveAndEnabled;
           }
   
   #if UNITY_EDITOR
           protected virtual void OnValidate()
           {}
   
           protected virtual void Reset()
           {}
   #endif
           /// <summary>
           /// This callback is called if an associated RectTransform has its dimensions changed. The call is also made to all child rect transforms, even if the child transform itself doesn't change - as it could have, depending on its anchoring.
           /// </summary>
           protected virtual void OnRectTransformDimensionsChange()
           {}
   
           protected virtual void OnBeforeTransformParentChanged()
           {}
   
           protected virtual void OnTransformParentChanged()
           {}
   
           protected virtual void OnDidApplyAnimationProperties()
           {}
   
           protected virtual void OnCanvasGroupChanged()
           {}
   
           /// <summary>
           /// Called when the state of the parent Canvas is changed.
           /// </summary>
           protected virtual void OnCanvasHierarchyChanged()
           {}
   
           /// <summary>
           /// Returns true if the native representation of the behaviour has been destroyed.
           /// </summary>
           /// <remarks>
           /// When a parent canvas is either enabled, disabled or a nested canvas's OverrideSorting is changed this function is called. You can for example use this to modify objects below a canvas that may depend on a parent canvas - for example, if a canvas is disabled you may want to halt some processing of a UI element.
           /// </remarks>
           public bool IsDestroyed()
           {
               // Workaround for Unity native side of the object
               // having been destroyed but accessing via interface
               // won't call the overloaded ==
               return this == null;
           }
       }