UGUI-ContentSizeFitter之最简单实现maxSize限制

Posted 2023-02-05 KeepStudya

步骤

方法思路如下：

1. 复制ContentSizeFitter源码出来，改名为ContentSizeFitterEx （AddComponentMenu里面的名字也需要改。）
2. FitMode增加枚举MaxSize
3. 增加序列化属性m_MaxHorizontal和m_MaxVertical
4. 修改HandleSelfFittingAlongAxis增加maxSize判断
5. 编写GetMaxSize方法
6. 修改完毕替换场景里面的ContentSizeFitter为ContentSizeFitterEx

ContentSizeFitterEx完整源码

复制到项目里面任意位置即可

using System.Collections.Generic;
using UnityEngine.EventSystems;

namespace UnityEngine.UI

    internal static class SetPropertyUtility
    
        public static bool SetColor(ref Color currentValue, Color newValue)
        
            if (currentValue.r == newValue.r && currentValue.g == newValue.g && currentValue.b == newValue.b &&
                currentValue.a == newValue.a)
                return false;

            currentValue = newValue;
            return true;
        

        public static bool SetStruct<T>(ref T currentValue, T newValue) where T : struct
        
            if (EqualityComparer<T>.Default.Equals(currentValue, newValue))
                return false;

            currentValue = newValue;
            return true;
        

        public static bool SetClass<T>(ref T currentValue, T newValue) where T : class
        
            if ((currentValue == null && newValue == null) || (currentValue != null && currentValue.Equals(newValue)))
                return false;

            currentValue = newValue;
            return true;
        
    


    [AddComponentMenu("Layout/Content Size Fitter Ex", 141)]
    [ExecuteAlways]
    [RequireComponent(typeof(RectTransform))]
    /// <summary>
    /// Resizes a RectTransform to fit the size of its content.
    /// </summary>
    /// <remarks>
    /// The ContentSizeFitter can be used on GameObjects that have one or more ILayoutElement components, such as Text, Image, HorizontalLayoutGroup, VerticalLayoutGroup, and GridLayoutGroup.
    /// </remarks>
    public class ContentSizeFitterEx : UIBehaviour, ILayoutSelfController
    
        /// <summary>
        /// The size fit modes avaliable to use.
        /// </summary>
        public enum FitMode
        
            /// <summary>
            /// Don't perform any resizing.
            /// </summary>
            Unconstrained,

            /// <summary>
            /// Resize to the minimum size of the content.
            /// </summary>
            MinSize,

            MaxSize,

            /// <summary>
            /// Resize to the preferred size of the content.
            /// </summary>
            PreferredSize
        

        [SerializeField] protected FitMode m_HorizontalFit = FitMode.Unconstrained;
        [SerializeField] protected int m_MaxHorizontal = 900;
        [SerializeField] protected int m_MaxVertical = 100;

        /// <summary>
        /// The fit mode to use to determine the width.
        /// </summary>
        public FitMode horizontalFit
        
            get  return m_HorizontalFit; 
            set
            
                if (SetPropertyUtility.SetStruct(ref m_HorizontalFit, value)) SetDirty();
            
        

        [SerializeField] protected FitMode m_VerticalFit = FitMode.Unconstrained;

        /// <summary>
        /// The fit mode to use to determine the height.
        /// </summary>
        public FitMode verticalFit
        
            get  return m_VerticalFit; 
            set
            
                if (SetPropertyUtility.SetStruct(ref m_VerticalFit, value)) SetDirty();
            
        

        [System.NonSerialized] private RectTransform m_Rect;

        private RectTransform rectTransform
        
            get
            
                if (m_Rect == null)
                    m_Rect = GetComponent<RectTransform>();
                return m_Rect;
            
        

        // field is never assigned warning
#pragma warning disable 649
        private DrivenRectTransformTracker m_Tracker;
#pragma warning restore 649

        protected ContentSizeFitterEx()
        
        

        protected override void OnEnable()
        
            base.OnEnable();
            SetDirty();
        

        protected override void OnDisable()
        
            m_Tracker.Clear();
            LayoutRebuilder.MarkLayoutForRebuild(rectTransform);
            base.OnDisable();
        

        protected override void OnRectTransformDimensionsChange()
        
            SetDirty();
        

        private void HandleSelfFittingAlongAxis(int axis)
        
            FitMode fitting = (axis == 0 ? horizontalFit : verticalFit);
            if (fitting == FitMode.Unconstrained)
            
                // Keep a reference to the tracked transform, but don't control its properties:
                m_Tracker.Add(this, rectTransform, DrivenTransformProperties.None);
                return;
            

            m_Tracker.Add(this, rectTransform,
                (axis == 0 ? DrivenTransformProperties.SizeDeltaX : DrivenTransformProperties.SizeDeltaY));

            // Set size to min or preferred size
            if (fitting == FitMode.MinSize)
            
                rectTransform.SetSizeWithCurrentAnchors((RectTransform.Axis)axis,
                    LayoutUtility.GetMinSize(m_Rect, axis));
            
            else if (fitting == FitMode.MaxSize)
            
            	//增加maxSize判断返回
                rectTransform.SetSizeWithCurrentAnchors((RectTransform.Axis)axis, GetMaxSize(m_Rect, axis));
            
            else
            
                rectTransform.SetSizeWithCurrentAnchors((RectTransform.Axis)axis,
                    LayoutUtility.GetPreferredSize(m_Rect, axis));
            
        
		
		/// <summary>
        /// 增加maxSize获取
        /// </summary>
        /// <param name="rect"></param>
        /// <param name="axis"></param>
        /// <returns></returns>
        private float GetMaxSize(RectTransform rect, int axis)
        
            var size = axis == 0 ? LayoutUtility.GetPreferredWidth(rect) : LayoutUtility.GetPreferredHeight(rect);

            if (axis == 0)
            
                if (size > m_MaxHorizontal)
                
                    return m_MaxHorizontal;
                
            
            else
            
                if (size > m_MaxVertical)
                
                    return m_MaxVertical;
                
            

            return size;
        


        /// <summary>
        /// Calculate and apply the horizontal component of the size to the RectTransform
        /// </summary>
        public virtual void SetLayoutHorizontal()
        
            m_Tracker.Clear();
            HandleSelfFittingAlongAxis(0);
        

        /// <summary>
        /// Calculate and apply the vertical component of the size to the RectTransform
        /// </summary>
        public virtual void SetLayoutVertical()
        
            HandleSelfFittingAlongAxis(1);
        

        protected void SetDirty()
        
            if (!IsActive())
                return;

            LayoutRebuilder.MarkLayoutForRebuild(rectTransform);
        

#if UNITY_EDITOR
        protected override void OnValidate()
        
            SetDirty();
        

#endif
    

效果

优化Editor使用

当上面的操作改完之后发现我不选MaxSize也会一直显示MaxHroizontal和MaxVertical属性的设置，假如我想选择了MaxSize的时候才显示配置呢？ 增加ContentSizeFitterExEditor类即可，注意该类需要放到Editor目录下，例如我是这样子放的：

using UnityEngine;
using UnityEngine.UI;

namespace UnityEditor.UI

    [CustomEditor(typeof(ContentSizeFitterEx), true)]
    [CanEditMultipleObjects]
    /// <summary>
    /// Custom Editor for the ContentSizeFitter Component.
    /// Extend this class to write a custom editor for a component derived from ContentSizeFitter.
    /// </summary>
    public class ContentSizeFitterExEditor : SelfControllerEditor
    
        SerializedProperty m_HorizontalFit;
        SerializedProperty m_VerticalFit;
		//增加Max配置
        SerializedProperty m_MaxHorizontal;
        SerializedProperty m_MaxVertical;

        protected virtual void OnEnable()
        
            m_HorizontalFit = serializedObject.FindProperty("m_HorizontalFit");
            m_VerticalFit = serializedObject.FindProperty("m_VerticalFit");
			//增加属性获取
            m_MaxHorizontal = serializedObject.FindProperty("m_MaxHorizontal");
            m_MaxVertical = serializedObject.FindProperty("m_MaxVertical");
        

        public override void OnInspectorGUI()
        
            serializedObject.Update();

            EditorGUILayout.PropertyField(m_HorizontalFit, true);
            EditorGUILayout.PropertyField(m_VerticalFit, true);

			//判断选择了第二个MaxSize才显示max设置
            if (m_HorizontalFit.enumValueIndex == 2)
            
                EditorGUILayout.PropertyField(m_MaxHorizontal);
            
            //判断选择了第二个MaxSize才显示max设置
            if (m_VerticalFit.enumValueIndex == 2)
            
                EditorGUILayout.PropertyField(m_MaxVertical);
            

            serializedObject.ApplyModifiedProperties();

            base.OnInspectorGUI();
        
    

最后效果如下：