Unity中电量显示和充电状态

label显示电量，spBattery电量图标用来切换充电状态。代码如下：

using System.Linq;
using System.Text;
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class GUIMainSystemInfo : MonoBehaviour
{
    // Start is called before the first frame update
    [SerializeField]
    UILabel labelBattery;
    [SerializeField]
    UISprite spBattery;
    private float batteryLevel = 0;
    private float prevBatteryLevel = 0;
    private BatteryStatus batteryStatus;
    private BatteryStatus prevBatteryStatus;
    StringBuilder sb = new StringBuilder();
    void Start()
    {
        if (labelBattery)
        {
            StartCoroutine("UpdataBattery");
        }
    }

    //更新手机电量
    IEnumerator UpdataBattery()
    {
        while (true)
        {
            batteryLevel = SystemInfo.batteryLevel;
            batteryStatus = SystemInfo.batteryStatus;
            if (batteryLevel != prevBatteryLevel || batteryStatus != prevBatteryStatus)
            {
                prevBatteryLevel = SystemInfo.batteryLevel;
                prevBatteryStatus = SystemInfo.batteryStatus;
                if (batteryStatus == BatteryStatus.Charging)
                {
                    labelBattery.text = "";
                    spBattery.spriteName = "btnbatty2";
                }else
                {
                    labelBattery.text = GetBatteryLevel();
                    spBattery.spriteName = "btnbatty";
                }
            }
            yield return new WaitForSeconds(300f);
        }
    }
    //读取手机电量
    string GetBatteryLevel()
    {
        sb.Remove(0, sb.Length);
        sb.Append( Mathf.CeilToInt(SystemInfo.batteryLevel*100));
        sb.Append("%");
        return sb.ToString();
    }
}