IDEA自带的Terminal用起来很方便

连不上客户端，一直是离线状态，我看之前也有人发生过这种情况

老师，为什么我写到智能那块布局就不对了，智能部分嵌套的第一张居中大图的div的背景颜色显示在家电部分居中大图的下方，正常应该位于家电整体后面。     如果再往后写的话，内容会从家电居中大图开始往下继续撑开页面高度，我不知道是不是语法错了 

.content{
    width:100%;
    /*自动找高，清除子元素产生的浮动影响，*/
    overflow:hidden;
    background-color:#f5f5f5;
    padding:4px 0 12px;
}
/* 手机部分 */
/* 手机、家电、智能等标题部分前面居中的大图片样式 */
.phone-nav,.elc-nav{
    width:100%;
    height:120px;
    margin:22px 0;
}
.phone-nav>a>img{
    width:100%;
    height:100%;
}
/* 手机、家电等标题样式 */
.title{
    color:#333;
    font-size:22px;
    font-weight:200;
    line-height:58px;
    text-align:left;
}
/* 手机、家电等标题下a元素样式 */
.title>a{
    color:#424242;
    font-size:12px;
    line-height:58px;
    float:right;
}
/* 鼠标悬停在手机、家电等标题下的a元素上，字体颜色改变 */
.title>a:hover{
    color:#ff6700;
}
.phone-box,.elc-box{
    width:100%;
    height:614px;
}
.phone-box-left{
    width:234px;
    height:614px;
    float:left;
}
.phone-box-left img{
    width:100%;
    height:100%;
}
.phone-box-right{
    width:992px;
    height:614px;
    float:left;
}
.items-1{
    width:234px;
    height:260px;
    background-color:#fff;
    margin:0 0 14px 14px;
    padding:20px 0;
    float:left;
    transition:all .2s linear;
}
.img1{
    width:160px;
    height:160px;
    margin-bottom:18px;
}
.phone-box-left:hover,.phone-box-right>div:hover{
     box-shadow:0 15px 30px rgba(0,0,0,.1);
     transform:translate(0,-2px);
}
.name2{
    width: 214px;
    height: 21px;
    color: #333;
    font-size: 14px;
    line-height: 21px;
    margin: 0 auto 2px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.desc2{
    width: 214px;
    height: 18px;
    color: #b0b0b0;
    font-size: 12px;
    line-height: 18px;
    margin: 0 auto 10px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.price2{
    color: #ff6700;
    font-size: 14px;
}
/* 家电部分 */
/* 家电标题右侧span元素设置样式。字体大小颜色等样式在手机标题部分的a元素中已设置 */
.title span{
    margin-left:30px;
    transition:border .3s;
}
/* 鼠标悬停在家电标题右侧部分的span元素上，橘色的下边框显示 */
.title span:hover{
    border-bottom:2px solid #ff6700;
}
.items-2{
    width:234px;
    height:300px;
    background-color:#fff;
    margin-left:0;
    padding:0;
    float:left;
}
.items-last{
    width:234px;
    height:300px;
    margin-left:14px;
    float:left;
    position:relative;
}
.items-last>div{
    width:234px;
    height:143px;
    background-color:#fff;
    padding-top:50px;
    box-sizing:border-box;
}
.items-last>div:first-child{
    margin-bottom: 14px;
}
.items-2 img{
    width:100%;
    height:100%;
}
.price2>del{
    color: #b0b0b0;
    margin-left:0.5em;
}
.items-last img{
    width:80px;
    height:80px;
    position:absolute;
    top:32px;
    right:20px;
}
.items-last h3{ 
    position:absolute;
    top:50px;
    left:-40px;
}
.items-last p{
    position:absolute;
    top:76px;
    left:40px;
}
/* 智能部分 */
.smart-nav{
    width:100%;
    height:120px;
    margin:22px 0;
   /* 为什么智能标题上方的smart-nav根据背景颜色是显示在家电标题上方的elc-nav下？
   但smart-nav嵌套的图片却是出现在智能标题上方,且显示不全,页面高度不能由嵌套的图片撑开,侧边滚动条显示已经到底
    */
    background-color:red;
}
.smart-nav>a>img{
    width:100%;
    height:100%;
}
.smart .title{
    height:58px;
    line-height:58px;

}
.smart ul{
  padding-top:16px;
}
.smart li{
    margin-left:30px;
    float:left;
}

   <!--主体部分 -->
    <div class="content">
        <div class="wrap">
            <!-- 手机部分 -->
            <div class="phone">
                <div class="phone-nav">
                    <a href="#">
                    <img src="../images/431e5fd6bfd1b67d096928248be18303.jpg" alt="">
                    </a>
                </div>
                <h2 class="title">手机<a href="#">查看更多</a></h2> 
                <div class="phone-box">
                    <div class="phone-box-left">
                        <a href="#">
                            <img src="../images/c583f2edc613f1be20fa415910b13ce3.jpg" alt="">
                        </a>
                    </div>
                    <div class="phone-box-right">
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/5dc32ec73299ff79556dcd1cf0f0ac11.png" alt="" class="img1">
                                <h3 class="name2">小米MIX FOLD </h3>
                                <p class="desc2">折叠大屏｜自研芯片</p>
                                <p class="price2">9999元起</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/eb69512d9d6430d865d457ec52eebb51.png" alt="" class="img1">
                                <h3 class="name2">小米11 Ultra </h3>
                                <p class="desc2">1.12''GN2｜2K四微曲屏</p>
                                <p class="price2">5999元起</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/34caee2c867bfd8c5e0dc2d8c663e121.jpg" alt="" class="img1">
                                <h3 class="name2">小米11 Pro </h3>
                                <p class="desc2">1.12''GN2｜骁龙888</p>
                                <p class="price2">4999元起</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/cb554f30eaa0316b0a736c3d59f21584.png" alt="" class="img1">
                                <h3 class="name2">小米11 青春版  </h3>
                                <p class="desc2">小米11 青春版 轻薄</p>
                                <p class="price2">2299元起</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/d47f7ecaa04d92bf2790d4a5d53d9099.png" alt="" class="img1">
                                <h3 class="name2">黑鲨4 Pro</h3>
                                <p class="desc2">黑鲨4 Pro</p>
                                <p class="price2">3999元起</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/c21247abf4bc610cd86fe00601b0f766.png" alt="" class="img1">
                                <h3 class="name2">黑鲨4 </h3>
                                <p class="desc2">黑鲨4 磁动力升降肩键</p>
                                <p class="price2">2499元起</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/b3553083a4975325eab6470d94465548.jpg" alt="" class="img1">
                                <h3 class="name2">小米10S </h3>
                                <p class="desc2">骁龙870 | 对称式双扬立体声</p>
                                <p class="price2">3299元起</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/68217751d12b1bfd2f9766e458b5e2dd.jpg" alt="" class="img1">
                                <h3 class="name2">Redmi K40 Pro 系列 </h3>
                                <p class="desc2">骁龙888 / E4 旗舰直屏</p>
                                <p class="price2">2799元起</p>
                            </a>
                        </div>
                    </div>
                </div>
            </div>
            <!-- 家电部分 -->
            <div class="elc">
                    <div class="elc-nav">
                        <a href="#">
                            <img src="../images/41d16e66381cfeda7b6b39ab67678d5e.jpg" alt="">  
                        </a>
                        <h2 class="title">家电
                            <a href="#">
                                <span>热门</span>
                                <span>电视影音</span>
                            </a>
                        </h2>
                        <div class="elc-box">
                            <div class="items-2">
                            <a href="#">
                                <img src="../images/116fc43816b87192be4e67cf762e8da5.jpeg" alt="">
                            </a>
                            </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/03a9e7e96a09d256ca1badeec186c859.jpg" alt=""  class="img1">
                                <h3 class="name2">小米全面屏电视65英寸 E65X </h3>
                                <p class="desc2">全面屏设计</p>
                                <p class="price2">2999元<del class="original">3299元</del></p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/20d36fbaa18625e4fe507af31e4e9f83.jpg" alt="" class="img1">
                                <h3 class="name2">全面屏电视E43K  </h3>
                                <p class="desc2">全面屏设计，海量内容</p>
                                <p class="price2">1349元<del class="original">1500元</del></p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/9d8674cd21c486feff5328772ab9cf01.jpg" alt="" class="img1">
                                <h3 class="name2">小小米电视4A 70英寸 </h3>
                                <p class="desc2">大屏更享受</p>
                                <p class="price2">3599元<del class="original">3900元</del></p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/6bed167fc905bab57dee478bcf1e5e0d.JPG" alt="" class="img1">
                                <h3 class="name2">米家互联网对开门冰箱 540L </h3>
                                <p class="desc2">重磅新品福利特惠</p>
                                <p class="price2">2999元<del class="original">3600元</del></p>
                            </a>
                        </div>
                        <div class="items-2">
                            <a href="#">
                                <img src="../images/dfbdabe36b2d630d57a015e6fb5eb3ea.jpg" alt="">
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/b8c63a2024528fe5410ebe669b7d2407.jpg" alt="" class="img1">
                                <h3 class="name2">Redmi全自动波轮洗衣机1A 8kg</h3>
                                <p class="desc2">一键操作，父母都爱用</p>
                                <p class="price2">849元<del class="original">899元</del></p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/74e573c4c0d89048392d14831cc507d5.jpg" alt="" class="img1">
                                <h3 class="name2">Air 13.3" 2019款 </h3>
                                <p class="desc2">新一代独立显卡</p>
                                <p class="price2">6299元</p>
                            </a>
                        </div>
                        <div class="items-1">
                            <a href="#">
                                <img src="../images/7e5f89adf98ab3fccb34012b5209cd58.jpg" alt="" class="img1">
                                <h3 class="name2">米家互联网烟灶套装（天然气）</h3>
                                <p class="desc2">点火排烟，风随火动</p>
                                <p class="price2">2298元</p>
                            </a>
                        </div>
                        <div class="items-last">
                            <div>
                                <a href="#">
                                    <img src="../images/1612c93ad4756215774a0dbec7a81bb2.jpg" alt="">
                                    <h3 class="name2">米家电烤箱 </h3>
                                    <p class="price2">279元</p>
                                </a>
                            </div>
                            <div>
                                <a href="#">
                                  浏览更多
                                </a>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
            <!-- 智能部分 -->
            <div class="smart">
                <div class="smart-nav">
                    <a href="#">
                    <img src="../images/59e8fc8ba9718c266882719fb4bbcedd.jpg" alt="">
                    </a>
                </div>
                <h2 class="title">智能 
                    <ul>
                        <li><a href="#">热门</a></li>
                        <li><a href="#">安防</a></li>
                        <li><a href="#">出行</a></li>
                    </ul>
                   
                </h2>
                <div class="smart-box">


                </div>

            </div>
        </div>
    </div>
</body> 
</html>

老师，为什么会出现这个错误呢。我看视频老师讲的就可以这样引用。

老师，请问圈起来的部分是什么意思。。可以不配置吗

老师，我现在这个网能ping通，然后我也按照您给其他同学说的，删了这个txt文件。我还按照网上说的配置的DNS，但是yum就是不行。我想换阿里的yum源，提示我command not found。现在是真的没办法了，已经弄了很久了

老师，只有一个结束，没有视频里的设置，而且导入后pom文件里都是红色----------------

视频最后调用父类私有属性的方法：子类对象._父类名__私有属性

与我们之前学习到的外部调用私有属性：对象._类名__私有属性，这两者好像没有区别，本质应该是一样的吧

from tkinter import *
def bgUpdate(source):   #事件调用
    '''更改窗口背景颜色'''
    red=rSlinder.get()
    green=gSlinder.get()
    blue=bSlinder.get()
    print("R=%d,G=%d,B=%d" %(red,green,blue))
    myColor="#%02x%02x%02x" %(red,green,blue)
    root.config(bg=myColor)

root=Tk()
root.title("flysnow")
root.geometry("360x240")
fm=Frame(root)
fm.pack()

rSlinder=Scale(fm,from_=0,to=255,command=bgUpdate)
gSlinder=Scale(fm,from_=0,to=255,command=bgUpdate)
bSlinder=Scale(fm,from_=0,to=255,command=bgUpdate)

rSlinder.grid(row=0,column=0)
gSlinder.grid(row=0,column=1)
bSlinder.grid(row=0,column=2)

gSlinder.set(125)

root.mainloop()

问题描述：为什么这里bgUpdate() 加个source 进行事件绑定，否则程序报错。command一般不用事件绑定的吗？

视频是不是有地方漏了？我按照老师的删除，跑起来就报错了

这节课只是看看源码吧，这要是完全理解感觉有点困难呀

老师，我把源缓存了淘宝镜像了，但是还是卡在这20分钟没变了

请问老师为什么不定义Engine类成员变量engine会报错？这有什么关联吗？

老师，str()的作用是什么，我还是不是很清楚，为什么print(p)和p.__str__()返回的值不同呢

老师，为什么我用 "..  或  . " 做包内引用总报错，未指定父类报名，代码未用#标识的