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;