[System.Serializable]
public class Test 
{
    public string name;
    public int age;
}

using System.Collections.Generic;
using UnityEngine;
[CreateAssetMenu]
public class TestSO : ScriptableObject
{
    public List<Test> testList;
}

using UnityEngine;
using UnityEditor;
[CustomPropertyDrawer(typeof(Test))]
public class TestDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        var spName = property.FindPropertyRelative("name");
        var spAge = property.FindPropertyRelative("age");

        var rect1 = position;
        var rect2 = position;

        var indentlevel = EditorGUI.indentLevel;
        var lableWidth = EditorGUIUtility.labelWidth;
        EditorGUI.indentLevel = 2;
        EditorGUIUtility.labelWidth = 60;

        rect1.width = position.width / 2;
        rect1.height = EditorGUIUtility.singleLineHeight;

        rect2.width = position.width / 2;
        rect2.height = EditorGUIUtility.singleLineHeight;

        rect2.x = position.width / 2+40;
        rect2.y = rect1.y;

        EditorGUI.PropertyField(rect1, spName, new GUIContent("名字"));
        EditorGUI.PropertyField(rect2, spAge, new GUIContent("年齡"));

        EditorGUI.indentLevel = indentlevel;
        EditorGUIUtility.labelWidth = lableWidth;

        //EditorGUI.DrawRect(rect1, Color.green);
        //EditorGUI.DrawRect(rect2, Color.gray);
    }

    //獲取屬性高度
    public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
    {
        return base.GetPropertyHeight(property, label);
    }
}

using UnityEngine;
using UnityEditor;
using UnityEditorInternal;
[CustomEditor(typeof(TestSO))]
public class TestSOEditor : Editor
{
    SerializedProperty sPTestList;
    ReorderableList arrayList;

    private void OnEnable()
    {
        sPTestList = serializedObject.FindProperty("testList");

        if (arrayList == null)
        {
            arrayList = new ReorderableList(serializedObject, sPTestList, true, true, true, true);    
            //繪制Header
            arrayList.drawHeaderCallback += DrawHeader;
            //繪制數(shù)組元素
            arrayList.drawElementCallback += DrawElement;
            //獲取數(shù)組的高度
            arrayList.elementHeightCallback += DrawElementHeight;
        }
    }

    void DrawHeader(Rect rect)
    {
        EditorGUI.LabelField(rect, "測(cè)試列表");
    }

    void DrawElement(Rect rect, int index, bool isActive, bool isFocused)
    {
        var element = sPTestList.GetArrayElementAtIndex(index);
        var arrowRect = rect;

        int indentLevel = EditorGUI.indentLevel;
        EditorGUI.indentLevel = 1;
        arrowRect.height = EditorGUIUtility.singleLineHeight;
        element.isExpanded = EditorGUI.Foldout(arrowRect, element.isExpanded, new GUIContent("元素" + index));
        EditorGUI.indentLevel = indentLevel;

        //EditorGUI.DrawRect(rect, Color.red);
        //EditorGUI.DrawRect(arrowRect, Color.blue);

        if (element.isExpanded)
        {
            rect.y += arrowRect.height;
            EditorGUI.PropertyField(rect, element);
        }
    }

    float DrawElementHeight(int index)
    {
        var element = sPTestList.GetArrayElementAtIndex(index);
        var height = EditorGUIUtility.singleLineHeight;//折疊箭頭的高度   
        if (element.isExpanded)//如果元素展開(kāi) 獲取展開(kāi)內(nèi)容的高度和箭頭的高度之和
            height += EditorGUI.GetPropertyHeight(element);
        return height;
    }

    public override void OnInspectorGUI()
    {
        serializedObject.Update();
        arrayList.DoLayoutList();
        serializedObject.ApplyModifiedProperties();
    }
}