起因

Unity 的Asset 文件如果设置为 readonly 是不可以 Serialize 的,而且在编辑器中,有些属性不希望被修改,这篇文章主要解决上述的两个问题

运行时的 "readonly"

但是下面的做法会导致在Editor中显示为 <Test>k__BackingField

[CreateAssetMenu(fileName = "GameData.asset", menuName = "GameConfig/GameData")]
    public class InitializeGameData : ScriptableObject {
        [field: SerializeField]
        public int Test { get; private set; }
    }

修复Editor 显示问题

这里需要重新绘制Test属性的显示,Title用于修改List对象的显示名,EnumName用于修改属性的显示名,这里使用EnumName

using UnityEngine;
#if UNITY_EDITOR
using System;
using UnityEditor;
using System.Reflection;
using System.Text.RegularExpressions;
#endif

#if UNITY_EDITOR
[AttributeUsage(AttributeTargets.Field)]
#endif
public class TitleAttribute : PropertyAttribute {
    public string title;
    public string htmlColor;

    public TitleAttribute(string title, string htmlColor = "#FFFFFF") {
        this.title = title;
        this.htmlColor = htmlColor;
    }
}

#if UNITY_EDITOR
[CustomPropertyDrawer(typeof(TitleAttribute))]
public class TitleAttributeDrawer : DecoratorDrawer {

    // 文本样式
    private GUIStyle style = new GUIStyle();

    public override void OnGUI(Rect position) {
        // 获取Attribute
        TitleAttribute attr = (TitleAttribute)attribute;

        // 转换颜色
        Color color = htmlToColor(attr.htmlColor);

        // 重绘GUI
        position = EditorGUI.IndentedRect(position);
        style.normal.textColor = color;
        GUI.Label(position, attr.title, style);
    }

    public override float GetHeight() {
        return base.GetHeight() - 4;
    }

    private Color htmlToColor(string hex) {
        // 默认黑色
        if(string.IsNullOrEmpty(hex)) return Color.black;

        // 转换颜色
        hex = hex.ToLower();
        if(hex.IndexOf("#") == 0 && hex.Length == 7) {
            int r = Convert.ToInt32(hex.Substring(1, 2), 16);
            int g = Convert.ToInt32(hex.Substring(3, 2), 16);
            int b = Convert.ToInt32(hex.Substring(5, 2), 16);
            return new Color(r / 255f, g / 255f, b / 255f);
        } else if(hex == "red") {
            return Color.red;
        } else if(hex == "green") {
            return Color.green;
        } else if(hex == "blue") {
            return Color.blue;
        } else if(hex == "yellow") {
            return Color.yellow;
        } else if(hex == "black") {
            return Color.black;
        } else if(hex == "white") {
            return Color.white;
        } else if(hex == "cyan") {
            return Color.cyan;
        } else if(hex == "gray") {
            return Color.gray;
        } else if(hex == "grey") {
            return Color.grey;
        } else if(hex == "magenta") {
            return Color.magenta;
        } else {
            return Color.black;
        }
    }

}

#endif

#if UNITY_EDITOR
[AttributeUsage(AttributeTargets.Field)]

#endif
public class EnumNameAttribute : PropertyAttribute {

    /// <summary> 枚举名称 </summary>
    public string name;

    public EnumNameAttribute(string name) {
        this.name = name;
    }

}

#if UNITY_EDITOR
[CustomPropertyDrawer(typeof(EnumNameAttribute))]
public class EnumNameDrawer : PropertyDrawer {

    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label) {
        // 替换属性名称
        EnumNameAttribute rename = (EnumNameAttribute)attribute;
        label.text = rename.name;

        // 重绘GUI
        bool isElement = Regex.IsMatch(property.displayName, "Element \\d+");
        if(isElement) label.text = property.displayName;
        if(property.propertyType == SerializedPropertyType.Enum) {
            drawEnum(position, property, label);
        } else {
            EditorGUI.PropertyField(position, property, label, true);
        }
    }

    // 绘制枚举类型
    private void drawEnum(Rect position, SerializedProperty property, GUIContent label) {
        EditorGUI.BeginChangeCheck();

        // 获取枚举相关属性
        Type type = fieldInfo.FieldType;
        string[] names = property.enumNames;
        string[] values = new string[names.Length];
        while(type.IsArray) type = type.GetElementType();

        // 获取枚举所对应的名称
        for(int i = 0; i < names.Length; i++) {
            FieldInfo info = type.GetField(names[i]);
            EnumNameAttribute[] atts = (EnumNameAttribute[])info.GetCustomAttributes(typeof(EnumNameAttribute), false);
            values[i] = atts.Length == 0 ? names[i] : atts[0].name;
        }

        // 重绘GUI
        int index = EditorGUI.Popup(position, label.text, property.enumValueIndex, values);
        if(EditorGUI.EndChangeCheck() && index != -1) property.enumValueIndex = index;
    }

}
#endif

实际使用如下

[field: SerializeField, EnumName("Test")]
public int Test { get; private set; }

Editor 模式下的 ReadOnly

这里使用Editor提供的API设置为Editor模式下不可修改

#if UNITY_EDITOR
using UnityEditor;
#endif
using UnityEngine;

public class ReadOnlyAttribute : PropertyAttribute {

}

#if UNITY_EDITOR
    [CustomPropertyDrawer(typeof(ReadOnlyAttribute))]
public class ReadOnlyDrawer : PropertyDrawer {
    public override float GetPropertyHeight(SerializedProperty property,
                                            GUIContent label) {
        return EditorGUI.GetPropertyHeight(property, label, true);
    }

    public override void OnGUI(Rect position,
                               SerializedProperty property,
                               GUIContent label) {
        GUI.enabled = false;
        EditorGUI.PropertyField(position, property, label, true);
        GUI.enabled = true;
    }
}
#endif

实际使用

[ReadOnly] public int Test;

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