/// <summary>
/// 工厂方法：获得类的唯一实例
/// </summary>
/// <returns>符号表管理器</returns>
public static SymbolTable GetInstance()
{
return synObject == null ? synObject = new SymbolTable() : synObject;
}
/// <summary>
/// 将运行时环境恢复最初状态
/// </summary>
public void Reset()
{
this.CallStack = new StackMachine();
this.Symbols = SymbolTable.GetInstance();
this.Screen = null;
this.PlayingBGM = null;
//this.TitlePoint = new KeyValuePair<string, SceneAction>(null, null);
}
