using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.UI.CoroutineTween;
using UnityEngine.UI;
using UnityEngine;public class DropdownEx : Dropdown
{public bool m_AlwaysCallback = false;public void Show(){base.Show();Transform toggleRoot = transform.FindChild("Dropdown List/Viewport/Content");Toggle[] toggleList = toggleRoot.GetComponentsInChildren<Toggle>(false);for(int i = 0; i < toggleList.Length; i++){Toggle temp = toggleList[i];temp.onValueChanged.RemoveAllListeners();temp.isOn = false;temp.onValueChanged.AddListener(x => OnSelectItemEx(temp));}}public override void OnPointerClick(PointerEventData eventData){Show();}public void OnSelectItemEx(Toggle toggle){if (!toggle.isOn){toggle.isOn = true;return;}int selectedIndex = -1;Transform tr = toggle.transform;Transform parent = tr.parent;for (int i = 0; i < parent.childCount; i++){if (parent.GetChild(i) == tr){// Subtract one to account for template child.selectedIndex = i - 1;break;}}if (selectedIndex < 0)return;if (value == selectedIndex && m_AlwaysCallback)onValueChanged.Invoke(value);elsevalue = selectedIndex;Hide();}}

using UnityEngine.UI;
using UnityEditor;
using UnityEditor.UI;[CustomEditor(typeof(DropdownEx), true)]
[CanEditMultipleObjects]
public class DropdownExEditor : DropdownEditor
{SerializedProperty m_AlwaysCallback;protected override void OnEnable(){base.OnEnable();m_AlwaysCallback = serializedObject.FindProperty("m_AlwaysCallback");}public override void OnInspectorGUI(){base.OnInspectorGUI();EditorGUILayout.PropertyField(m_AlwaysCallback);serializedObject.ApplyModifiedProperties();}
}