c# - 如何使用 bool 值在 Unity 检查器中启用/禁用列表？

Question

我有一个 ScriptableObject脚本调用 Level ，在关卡脚本中，我有一个游戏对象列表和一个名为 introduceNewEnemies 的 bool 变量.

我想要做的是:我想在 bool 变量打开时启用该游戏对象列表，并在它关闭时使用 Unity 自定义检查器方法或属性隐藏/灰色(我们无法向其添加元素)它抽屉。做起来有那么难吗？

Answer 1

最好的方法是自定义属性。我将首先展示最终结果:

使用一个字段来隐藏/显示另一个字段:

public bool showHideList = false; 
[ShowIf(ActionOnConditionFail.DontDraw, ConditionOperator.And, nameof(showHideList))]
public string aField = "item 1";

使用一个字段来启用/禁用另一个字段:

public bool enableDisableList = false;

[ShowIf(ActionOnConditionFail.JustDisable, ConditionOperator.And, 
nameof(enableDisableList))]
public string anotherField = "item 2";

使用方法获取条件值:

[ShowIf(ActionOnConditionFail.JustDisable, ConditionOperator.And,nameof(CalculateIsEnabled))]
public string yetAnotherField = "one more";    public 
bool CalculateIsEnabled()    
{
    return true;    
}

在同一字段上使用多个条件:

public bool condition1;    
public bool condition2;    
[ShowIf(ActionOnConditionFail.JustDisable, ConditionOperator.And, nameof(condition1), 
nameof(condition2))]    
public string oneLastField= "last field";

是怎么做的？

定义一次允许多个条件的选项:

public enum ConditionOperator
{
    // A field is visible/enabled only if all conditions are true.
    And,
    // A field is visible/enabled if at least ONE condition is true.
    Or,
}

定义条件失败时如何绘制字段:

public enum ActionOnConditionFail
{
    // If condition(s) are false, don't draw the field at all.
    DontDraw,
    // If condition(s) are false, just set the field as disabled.
    JustDisable,
}

现在创建一个自定义属性类，以保存有关条件的数据:

using System;
using UnityEngine;
[AttributeUsage(AttributeTargets.Field, AllowMultiple = false, Inherited = true)]
public class ShowIfAttribute : PropertyAttribute
{
    public ActionOnConditionFail Action {get;private set;}
    public ConditionOperator Operator {get;private set;}
    public string[] Conditions {get;private set;}

     public ShowIfAttribute(ActionOnConditionFail action, ConditionOperator conditionOperator, params string[] conditions)
    {
        Action  = action;
        Operator = conditionOperator;
        Conditions = conditions;
    }
}

我们告诉 Unity 如何使用 ShowIfAttribute 处理字段的重要部分，此 Drawer 脚本需要位于任何“编辑器”文件夹下:

using System.Reflection;
using UnityEditor;
using System.Collections.Generic;
using System;
using System.Linq;
using UnityEngine;

[CustomPropertyDrawer(typeof(ShowIfAttribute), true)]
public class ShowIfAttributeDrawer : PropertyDrawer
{

    #region Reflection helpers.
    private static MethodInfo GetMethod(object target, string methodName)
    {
        return GetAllMethods(target, m => m.Name.Equals(methodName, 
                  StringComparison.InvariantCulture)).FirstOrDefault();
    }

    private static FieldInfo GetField(object target, string fieldName)
    {
        return GetAllFields(target, f => f.Name.Equals(fieldName, 
              StringComparison.InvariantCulture)).FirstOrDefault();
    }
    private static IEnumerable<FieldInfo> GetAllFields(object target, Func<FieldInfo, 
            bool> predicate)
    {
        List<Type> types = new List<Type>()
            {
                target.GetType()
            };

        while (types.Last().BaseType != null)
        {
            types.Add(types.Last().BaseType);
        }

        for (int i = types.Count - 1; i >= 0; i--)
        {
            IEnumerable<FieldInfo> fieldInfos = types[i]
                .GetFields(BindingFlags.Instance | BindingFlags.Static | 
   BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.DeclaredOnly)
                .Where(predicate);

            foreach (var fieldInfo in fieldInfos)
            {
                yield return fieldInfo;
            }
        }
    }
    private static IEnumerable<MethodInfo> GetAllMethods(object target, 
  Func<MethodInfo, bool> predicate)
    {
        IEnumerable<MethodInfo> methodInfos = target.GetType()
            .GetMethods(BindingFlags.Instance | BindingFlags.Static | 
  BindingFlags.NonPublic | BindingFlags.Public)
            .Where(predicate);

        return methodInfos;
    }
    #endregion

    private bool MeetsConditions(SerializedProperty property)
    {
        var showIfAttribute = this.attribute as ShowIfAttribute;
        var target = property.serializedObject.targetObject;
        List<bool> conditionValues = new List<bool>();

        foreach (var condition in showIfAttribute.Conditions)
        {
            FieldInfo conditionField = GetField(target, condition);
            if (conditionField != null &&
                conditionField.FieldType == typeof(bool))
            {
                conditionValues.Add((bool)conditionField.GetValue(target));
            }

            MethodInfo conditionMethod = GetMethod(target, condition);
            if (conditionMethod != null &&
                conditionMethod.ReturnType == typeof(bool) &&
                conditionMethod.GetParameters().Length == 0)
            {
                conditionValues.Add((bool)conditionMethod.Invoke(target, null));
            }
        }

        if (conditionValues.Count > 0)
        {
            bool met;
            if (showIfAttribute.Operator == ConditionOperator.And)
            {
                met = true;
                foreach (var value in conditionValues)
                {
                    met = met && value;
                }
            }
            else
            {
                met = false;
                foreach (var value in conditionValues)
                {
                    met = met || value;
                }
            }
            return met;
        }
        else
        {
            Debug.LogError("Invalid boolean condition fields or methods used!");
            return true;
        }
    }
    public override float GetPropertyHeight(SerializedProperty property, GUIContent 
                 label)
    {
        // Calcluate the property height, if we don't meet the condition and the draw 
    mode is DontDraw, then height will be 0.
        bool meetsCondition = MeetsConditions(property);
        var showIfAttribute = this.attribute as ShowIfAttribute;

        if (!meetsCondition && showIfAttribute.Action == 
                                       ActionOnConditionFail.DontDraw)
            return 0;
        return base.GetPropertyHeight(property, label);
    }

    public override void OnGUI(Rect position, SerializedProperty property, GUIContent 
           label)
    {
        bool meetsCondition = MeetsConditions(property);
        // Early out, if conditions met, draw and go.
        if (meetsCondition)
        {
            EditorGUI.PropertyField(position, property, label, true);
            return; 
        }

        var showIfAttribute = this.attribute as ShowIfAttribute;
        if(showIfAttribute.Action == ActionOnConditionFail.DontDraw)
        {
            return;
        }
        else if (showIfAttribute.Action == ActionOnConditionFail.JustDisable)
        {
            EditorGUI.BeginDisabledGroup(true);
            EditorGUI.PropertyField(position, property, label, true);
            EditorGUI.EndDisabledGroup();
        }

    }
}

下一步

实现反向条件处理程序，即编辑它以在条件为假时启用字段，反之亦然。

目前对于列表和数组，unit 将禁用/启用列表的元素，但保持启用列表计数字段，尝试实现一种解决方案来处理这种情况。