operate Index Up Down Left Right
{Stage1_Handler, stage1, stage4, stage7,...stage3, stage2},
{Stage2_Handler, stage2, stage5, stage8, stage1, stage3},
{Stage3_Handler,...stage3, stage6, stage9, stage2, stage1},
{Stage4_Handler, stage4, stage7, stage1, stage6, stage5...stage6},
{Stage6_Handler, stage6, stage9, stage3, stage5, stage4},
{Stage7_Handler, stage7, stage1...Handler, stage9, stage3, stage6, stage8, stage7},
};
2.3 定义两个变量保存当前场景和上一个场景
char current_stage=stage1