这里配置了一个lru，那另外两种也是这般配置吗？

再就是jcache这段文字看不懂哇

表格里面使用<thead><tbody><tfoot>是不是为了增强标签的语义性，跟不加这些 显示的效果页面是一样的吗

老师您好，我看到课堂中的txt文本笔记，是之前学过的吗？这个章节第一节课时老师就说重做系统后开始学习的，但是没有找到这个课程呀？

老师，数据库上的密码没有显示加密的结果。把pwd=pwd改为password=pwd后，反而出现”2000，异常错误“。

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com.bjsxtTestSuper {
    (String[] args) {
        ChildClass().f()}
    FatherClass {
        (){
            = System..println(+)}
    }
    ChildClass FatherClass {
        (){
            = System..println(+)System..println(+.)}

    }
}

为啥我提示

F:\JAVAproject\jlchen003\src\com\bjsxt\TestSuper.java:5:9

java: 无法从静态上下文中引用非静态 变量 this

为什么我预更新会失败？下面是我后台报的错误，会是什么原因呢？

class Benz:pass

class BMW:pass

class BYD:pass

老师这三行后面为什么写pass啊？什么意思？

老师，请问如何向云服务器拷贝JDK这个步骤可以再详细一点吗

我这个为什么出来图像是白的，哪里出错了

老师，我想问一下上传图片过后，访问不到是为什么，我看了fastdfs里面有图片数据，防火墙也关了

老师调用index校验的这个方法前面可以不用this吗

pygame,time
random
_display=pygame.display
COLOR_BLACK=pygame.Color(,,)
COLOR_RED=pygame.Color(,,)
():
    window=TANK_P1=SCREEN_HEIGHT=SCREEN_WIDTH=EnemyTank_list=[]
    EnemyTank_count=():
        ():
        _display.init()
        MainGame.window=_display.set_mode([MainGame.SCREEN_WIDTH,MainGame.SCREEN_HEIGHT])
        MainGame.TANK_P1 = Tank(, )
        .createEnemyTank()
        _display.set_caption()

        :
            time.sleep()
            MainGame.window.fill(COLOR_BLACK)
            .getEvent()
            MainGame.window.blit(.getTextface(%),(,))

            MainGame.TANK_P1.displayTank()

            .displayEnemyTank()
            MainGame.TANK_P1.stop == :
                MainGame.TANK_P1.move()
            _display.update()


    ():
        top = i (MainGame.EnemyTank_count):
            left = random.randint(, )
            speed = random.randint(, )
            eTank = EnemyTank(left, top, speed)
            MainGame.EnemyTank_list.append(eTank)


   ():
        eTank MainGame.EnemyTank_list:
            eTank.displayTank()
            eTank.randMove()

    ():
        ()
        ()

    (,text):
        pygame.font.init()
        font=pygame.font.SysFont(,)
        textSurface=font.render(text,,COLOR_RED)
        textSurface

():
        eventList=pygame.event.get()
        event eventList:
    event.type==pygame.QUIT:
                .endGame()
    event.type==pygame.KEYDOWN:
     event.key==pygame.K_LEFT:
                    ()
                    MainGame.TANK_P1.direction=MainGame.TANK_P1.stop=event.key==pygame.K_RIGHT:
                    ()
                    MainGame.TANK_P1.direction=MainGame.TANK_P1.stop=event.key == pygame.K_UP:
                        ()
                        MainGame.TANK_P1.direction = MainGame.TANK_P1.stop = event.key == pygame.K_DOWN:
                            ()
                            MainGame.TANK_P1.direction = MainGame.TANK_P1.stop = event.key==pygame.K_SPACE:
                    ()


             event.type==pygame.KEYUP:
                    event.key==pygame.K_LEFT event.key==pygame.K_RIGHT \
                        event.key == pygame.K_UP event.key==pygame.K_DOWN:
                     MainGame.TANK_P1.stop=():
    (,left,top):
        .images={
            :pygame.image.load(),
            : pygame.image.load(),
            : pygame.image.load(),
            : pygame.image.load()
        }

        .direction=.image=.images[.direction]
        .rect=.image.get_rect()
        .rect.left=left
        .rect.top=top
        .stop = .speed=():
        .image=.images[.direction]
        MainGame.window.blit(.image,.rect)


():
        .direction==:
            .rect.left>:
                .rect.left-=.speed
        .direction==:
            .rect.left+.rect.width<MainGame.SCREEN_WIDTH:
                .rect.left+=.speed
        .direction==:
            .rect.top > :
                 .rect.top-=.speed
        .direction==:
            .rect.top + .rect.height< MainGame.SCREEN_HEIGHT:
                .rect.top += .speed

    ():
        ():
        ():
        (Tank):
    ():
        ():
        (Tank):

    (,left,top,speed):
        .images={
            :pygame.image.load(),
            :pygame.image.load(),
            :pygame.image.load(),
            :pygame.image.load()
        }
        .direction=.randDirection()
        .image=.images[.direction]
        .rect=.image.get_rect()
        .rect.left=left
        .rect.top=top
        .speed=speed
        .stop=.step=():
            num=random.randint(,)
            num==:
                 num == :
                num == :
                num == :
                ():
        .step<=:
            .direction=.randDirection()
            .step=:
            .move()
            .step-=():
        ():
    ():
        ():
        ():
        ():
        ():
        ():
        ():
    ():
        ():
        ():
    ():
        ():
        ():
    ():
        ():
        __name__==:
    MainGame().startGame()

报错

"C:\Program Files (x86)\Python36-32\python.exe" C:/Users/Administrator/Desktop/python课件/坦克游戏/代码/test/tank08.py

pygame 2.0.1 (SDL 2.0.14, Python 3.6.5)

Hello from the pygame community. https://www.pygame.org/contribute.html

Traceback (most recent call last):

  File "C:/Users/Administrator/Desktop/python课件/坦克游戏/代码/test/tank08.py", line 284, in <module>

    MainGame().startGame()

  File "C:/Users/Administrator/Desktop/python课件/坦克游戏/代码/test/tank08.py", line 28, in startGame

    self.createEnemyTank()

  File "C:/Users/Administrator/Desktop/python课件/坦克游戏/代码/test/tank08.py", line 59, in createEnemyTank

    eTank = EnemyTank(left, top, speed)

  File "C:/Users/Administrator/Desktop/python课件/坦克游戏/代码/test/tank08.py", line 208, in __init__

    self.image=self.images[self.direction]

KeyError: None

Process finished with exit code 1

老师，帮我看看是什么原因

这里if(name.equals(sell))可以么？

老师，字段被隐藏起来，那怎样才能让他重新显示呢？