创建GUISkin

设置自定义GUISkin

btn是一张图片

应用自定义GUISkin

using UnityEngine;
using System.Collections;

public class GUITest : MonoBehaviour {

    public GUISkin myGUISkin;

	void OnGUI () {
        GUI.skin = myGUISkin;
        if (GUILayout.Button("Button Use custom GUISkin"))
        {

        }
	}
}

运行效果