场景脚本，连续2次的问题 - Project1

#==============================================================================
# ■ Scene_RPG
#------------------------------------------------------------------------------
# 　处理查看画面的类。
#==============================================================================

class Scene_RPG
  def initialize
@a = 0
  end


#--------------------------------------------------------------------------
# ● 主处理
#--------------------------------------------------------------------------
def main
# 生成窗口
@spriteset = Spriteset_Map.new
@vs = Sprite.new
@vs.bitmap = RPG::Cache.title("VS")
@vs.x = 330
@vs.y = 65
@hero = Window_Hero.new
@hero.x -= 40
@hero.y -= 7
@key = Window_Key.new
@key.x -= 40
@key.y += 200
@font = Window_Font.new
@font.x -= 40
@font.y += 270
@RPG_battle = Window_RPG.new
@RPG_battle.x -= 80
@RPG_battle.y += 30
@actor = Window_Actor.new
@actor.x = 470
@actor.y = 78
@enemy = Window_Enemy.new
@enemy.x = 240
@enemy.y = 78
# 执行过渡
Graphics.transition
# 主循环
loop do
   # 刷新游戏画面
   Graphics.update
   # 刷新输入情报
   Input.update
   # 刷新画面
   update
   # 如果画面切换的话就中断循环
   if $scene != self
   break
   end
end

# 准备过渡
Graphics.freeze
# 释放窗口
@spriteset.dispose
@vs.dispose
@vs.bitmap.dispose
@RPG_battle.dispose
@actor.dispose
@enemy.dispose
@hero.dispose
@key.dispose
@font.dispose
# 如果在标题画面切换中的情况下
if $scene.is_a?(Scene_Title)
   # 淡入淡出画面
   Graphics.transition
   Graphics.freeze
end
end
#--------------------------------------------------------------------------
# ● 刷新画面
#--------------------------------------------------------------------------
def update

      # 获取地图ID
   newid = $game_map.map_id
   # 如果现在的地图的ID不是刚才显示的地图ID则开始显示
   if newid != @id
      @id = newid
   end
@a += 1
if @a == 10  #自行修改
   # 自动攻击
   $game_variables[4500] -= $game_variables[2]
   $game_system.se_play($data_system.battle_bgm)
   @wait_count = 10
   $game_variables[1]-= $game_variables[4600]
   @wait_count = 10
   if $game_variables[4500] <= 0 or $game_variables[1] <= 0
   $scene = Scene_Map.new
   end
   @a = 0
end
# 刷新窗口
@RPG_battle.update
@actor.update
@enemy.update
@hero.update
@key.update
@font.update
# 按下 B 键的情况下
if Input.trigger?(Input::B) and $game_variables[4500] <= 0
   # 演奏取消 SE
   $game_system.se_play($data_system.cancel_se)
   # 切换到菜单画面
   $scene = Scene_Map.new
   return
else
   @RPG_battle.update
end
# 按下 C 键的场合下
if Input.trigger?(Input::C)
   return
end
end
end