unity 实现使用三张图片来表达车速，通过传值达到车速

//速度
public Image SpeedNums_Unit;
public Image SpeedNums_Ten;
//public Image SpeedNums_Hundred;
//kw
public Image MileageNums_Unit;
public Image MileageNums_Ten;
///
/// 仪表速度UI
///
private void SpeedUI(string speedStr)
{
if (SpeedNums_Unit == null) return;
if (SpeedNums_Ten == null) return;
//if (SpeedNums_Hundred == null) return;

    string[] myArray = Tools.StringSplit(speedStr);
    int arrayLength = myArray.Length;
    if (arrayLength == 1)
    {
        SpeedNums_Unit.sprite = Tools.LoadResourcesAssets("LeftNumber/img_number_" + myArray[0]) as Sprite;
        SpeedNums_Unit.gameObject.SetActive(true);
        SpeedNums_Ten.gameObject.SetActive(false);
        //SpeedNums_Hundred.gameObject.SetActive(false);
    }
    if (arrayLength == 2)
    {
        SpeedNums_Unit.sprite = Tools.LoadResourcesAssets(&