Unity属性美化方法

以前看到插件的代码和其他人写的代码都带有一些新奇的玩意儿，嗯，特别羡慕。
然后找个时间去捣鼓一下，去翻unity manual，找到这个玩意儿。
效果：给类的公开字段添加EditorUI拉条，和只读的进度条，拉条的进度跟随字段数值改变；
涉及类：
SerializedProperty
https://docs.unity3d.com/ScriptReference/SerializedProperty.html
SerializedProperty和SerializedObject是用于以完全通用的方式编辑对象上的属性的类，可以自动处理撤销和为预置的UI设置样式。
Editor
https://docs.unity3d.com/cn/current/ScriptReference/Editor.html
从中派生自定义编辑器的基类。使用此类可为对象创建您自己的自定义检视面板和编辑器。
SerializedObject
https://docs.unity3d.com/cn/current/ScriptReference/SerializedObject.html

using UnityEditor;
using UnityEngine;
using System.Collections;

// Custom Editor using SerializedProperties.
// Automatic handling of multi-object editing, undo, and Prefab overrides.
[CustomEditor(typeof(MyPlayer))]//指定适用于那个类
[CanEditMultipleObjects]//可以被多选操作
public class MyPlayerEditor : Editor
{
    SerializedProperty damageProp;
    SerializedProperty armorProp;
    SerializedProperty gunProp;

    void OnEnable()
    {
        // Setup the SerializedProperties.
        damageProp = serializedObject.FindProperty("damage");
        armorProp = serializedObject.FindProperty("armor");
        gunProp = serializedObject.FindProperty("gun");
    }

    public override void OnInspectorGUI()//
    {
        // Update the serializedProperty - always do this in the beginning of OnInspectorGUI.
        serializedObject.Update();

        // Show the custom GUI controls.
        EditorGUILayout.IntSlider(damageProp, 0, 100, new GUIContent("Damage"));//创建一个拉条

        // Only show the damage progress bar if all the objects have the same damage value:
        if (!damageProp.hasMultipleDifferentValues)
            ProgressBar(damageProp.intValue / 100.0f, "Damage");//创建一个只读的进度条

        EditorGUILayout.IntSlider(armorProp, 0, 100, new GUIContent("Armor"));

        // Only show the armor progress bar if all the objects have the same armor value:
        if (!armorProp.hasMultipleDifferentValues)
            ProgressBar(armorProp.intValue / 100.0f, "Armor");

        EditorGUILayout.PropertyField(gunProp, new GUIContent("Gun Object"));

        // Apply changes to the serializedProperty - always do this in the end of OnInspectorGUI.
        serializedObject.ApplyModifiedProperties();
    }

    // Custom GUILayout progress bar.
    void ProgressBar(float value, string label)
    {
        // Get a rect for the progress bar using the same margins as a textfield:
        Rect rect = GUILayoutUtility.GetRect(18, 18, "TextField");
        EditorGUI.ProgressBar(rect, value, label);
        EditorGUILayout.Space();
    }
}