using UnityEngine;

 using System.Collections;

 using UnityEngine.UI;

 public class ExitGame : MonoBehaviour

 {

     [Tooltip("ExitMessage拖进来")]

     Text ExitMessageObj;

     float fadingSpeed = ;

     bool fading;

     float startFadingTimep;

     Color originalColor;

     Color transparentColor;

     string sss;

     void Start()

     {

         ExitMessageObj = this.GetComponent<Text>();

         originalColor = ExitMessageObj.color;

         transparentColor = originalColor;

         transparentColor.a = ;

         ExitMessageObj.text = "再次按下返回键退出游戏";

         ExitMessageObj.color = transparentColor;

     }

     void Update()

     {

         if (Input.GetKeyDown(KeyCode.Escape))

         {

             if (startFadingTimep == )

             {

                 ExitMessageObj.color = originalColor;

                 startFadingTimep = Time.time;

                 fading = true;

             }

             else

             {                                Application.Quit();//退出游戏

             }

         }

         if (fading)

         {

             ExitMessageObj.color = Color.Lerp(originalColor, transparentColor, (Time.time - startFadingTimep) * fadingSpeed);

             if (ExitMessageObj.color.a < 2.0 / )

             {

                 ExitMessageObj.color = transparentColor;

                 startFadingTimep = ;

                 fading = false;

             }

         }

     }

 }