/// <summary>
/// 把某个页面入栈， 把某个页面显示在界面上
/// </summary>
public void PushPanel(UIPanelType panelType)
{
if (m_panelStack == null)
{
m_panelStack = new Stack <IPanel>();
}
//判断一下栈里面是否有页面
if (m_panelStack.Count > 0)
{
IPanel topPanel = m_panelStack.Peek();
topPanel.OnPause();
}
IPanel panel = GetPanel(panelType);
panel.OnEnter();
m_panelStack.Push(panel);
}