HierachyUI.cs

using UnityEngine;
using System.Collections;
using UnityEditor;
[InitializeOnLoad]
public class HierachyUI
{

    static HierachyUI()
    {
        EditorApplication.hierarchyWindowItemOnGUI += HierarchyWindowItemGui;
    }

    private static bool needShowUI=true;
    private const string ToggleShowUI = "Tools/ShowAdditionalHierachyUI";

    [MenuItem(ToggleShowUI)]
    static void ToggleShow()
    {
        needShowUI = !needShowUI;
    }

    [MenuItem(ToggleShowUI,true)]
    static bool ToggleShowValidate()  //the function name doesnt matter here 
    {
        Menu.SetChecked(ToggleShowUI,needShowUI);
        return true;
    }


    static void HierarchyWindowItemGui(int instanceID, Rect selectionRect)
    {
        if (needShowUI == false)
        {
            return;
        }

        GameObject go = EditorUtility.InstanceIDToObject(instanceID) as GameObject;

        if (go)
        {
            bool selected = Selection.activeObject == go;

            //实际用的时候可以根据GameObject上面是否有某种Component或者其他条件来选择是否绘制这个对象的内容
            GUIStyle style = GUI.skin.label;
            GUIContent content = new GUIContent(go.name);
            float width = style.CalcSize(content).x;
            selectionRect.x = selectionRect.xMax - width;
            //Debug.Log("X max"+selectionRect.xMax+"X w"+width);
            Color defaltColor = GUI.color;
            GUI.color = selected ? Color.green : Color.cyan;

            GUI.Label(selectionRect, go.name);

            GUI.color = defaltColor;
        }
    }
}