游戏 gui button

using UnityEngine;
using System.Collections;

public class Gui : MonoBehaviour {

    public Texture2D buttonTexture;

    private string str;

    private int frameTime; 

    // Use this for initialization
    void Start () {
        str="请您点击按钮";
    }

    // Update is called once per frame
    void Update () {

    }

    void OnGUI()
    {
        GUI.Label (new Rect (, , Screen.width, ), str);

        if (GUI.Button (new Rect (, , buttonTexture.width, buttonTexture.height), buttonTexture)) {

            str="您点击了图片按钮";
        }
        GUI.color = Color.green;
        GUI.backgroundColor = Color.red;
        if (GUI.Button (new Rect (, , , ), "文字按钮")) {

            str="您点击了文字按钮";
        }

        GUI.color = Color.yellow;
        GUI.backgroundColor = Color.black;

        if (GUI.RepeatButton (new Rect (, , , ), "按钮按下中")) {

            str=frameTime+"";
            frameTime++;
        }

    }
}