【vue学习】3.本地应用——显示切换,属性绑定

2020-12-18 11:12:37 浏览数 (1)

【vue学习】3.本地应用——显示切换,属性绑定

v-for

作用:根据数据生成列表结构

代码语言:javascript复制
<body>
    <!-- 开发环境版本,包含了有帮助的命令行警告 -->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <div id="app">
        <ul>
            <!-- 索引index 从0开始 -->
            <li v-for="(item,index) in arr">{{item}},{{index}}</li>
            <li v-for="item in people" v-bind:title="item.age">{{item.name}}</li>
        </ul>
    </div>

    <script>
        var app = new Vue({
            el:"#app",
            data:{
                arr:[1,2,3,4,5],
                people:[
                    {name:"zhangsan",
                    age:15},
                    {name:"lisi",
                    age:17},
                ]
            }
        })
    </script>
</body>
  • 数组经常与v-for结合使用
  • 语法是(item,index) in 数据

v-on(补充)

作用: 传递自定义参数,事件修饰符

代码语言:javascript复制
<body>
    <!-- 开发环境版本,包含了有帮助的命令行警告 -->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <div id="app">
        <input type="button" value="doIt" @click="doIt(666)" />
   <!-- 事件修饰符 -->
        <input type="text" @keyup.enter="sayHi"/>
    </div>

    <script>
        var app = new Vue({
            el:"#app",
            methods:{
                doIt:function(p1){
                    console.log("doit" p1);
                },
                sayHi:function(){
                    alert("吃饭啦");
                }
            }
        })
    </script>
</body>
  • 事件绑定的方法写成函数调用的形式,可以传入自定义参数。
  • 定义方法时需要定义形参来接受传入的实参
  • 事件的后面跟上.修饰符可以对事件进行限制

v-model

作用:获取和设置表单元素的值(双向数据绑定)

代码语言:javascript复制
<body>
    <!-- 开发环境版本,包含了有帮助的命令行警告 -->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <div id="app">
        <input type="text" v-model="message" @keyup.enter="getM"/>
        <h2>{{message}}</h2>
        <input type="button" value="change"  @click="setM" />
    </div>

    <script>
        var app = new Vue({
            el:"#app",
            data:{
                message:"v-model绑定数据"
            },
            methods:{
                getM(){
                    alert(this.message);
                },
                setM(){
                    this.message  = "改Message";
                }
            }
        })
    </script>
</body>
  • 绑定的数据会和表单元素值相关联
  • 绑定的数据<---- ----> 表单元素的值

记事本开发

html文件

代码语言:javascript复制
<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
    <title>记事本</title>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
    <meta name="robots" content="noindex, nofollow" />
    <meta name="googlebot" content="noindex, nofollow" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <link rel="stylesheet" type="text/css" href="./index.css" />
  </head>

  <body>
    <!-- 主体区域 -->
    <section id="todoapp">
      <!-- 输入框 -->
      <header class="header">
        <h1>记事本</h1>
        <input
          v-model="inputValue"
          autofocus="autofocus"
          autocomplete="off"
          placeholder="请输入任务"
          class="new-todo"
          @keyup.enter="add"
        />
      </header>
      <!-- 列表区域 -->
      <section class="main">
        <ul class="todo-list">
          <li class="todo" v-for="(item,index) in list">
            <div class="view">
              <span class="index">{{index 1}}.</span> <label>{{item}}</label>
              <button class="destroy" @click="remove(index)"></button>
            </div>
          </li>
        </ul>
      </section>
      <!-- 统计和清空 -->
      <footer class="footer">
        <span class="todo-count" v-if="list.length !=0"> <strong>{{list.length}}</strong> items left </span>
        <button class="clear-completed" @click="clear" v-show="list.length!=0">
          Clear
        </button>
      </footer>
    </section>
    <!-- 开发环境版本,包含了有帮助的命令行警告 -->
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script>
      var app = new Vue({
        el:"#todoapp",
        data:{
          list:["写代码","吃饭饭","睡觉觉"],
          inputValue:"好好学习,天天向上"
        },
        methods:{
          add:function(){
            this.list.push(this.inputValue);
          },
          remove:function(index){
            this.list.splice(index,1);
          },
          clear:function(){
            this.list = [];
          }
        }
      })
    </script>
  </body>
</html>

css文件:

代码语言:javascript复制
html,
body {
  margin: 0;
  padding: 0;
}
body {
  background: #fff;
}
button {
  margin: 0;
  padding: 0;
  border: 0;
  background: none;
  font-size: 100%;
  vertical-align: baseline;
  font-family: inherit;
  font-weight: inherit;
  color: inherit;
  -webkit-appearance: none;
  appearance: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font: 14px "Helvetica Neue", Helvetica, Arial, sans-serif;
  line-height: 1.4em;
  background: #f5f5f5;
  color: #4d4d4d;
  min-width: 230px;
  max-width: 550px;
  margin: 0 auto;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-weight: 300;
}

:focus {
  outline: 0;
}

.hidden {
  display: none;
}

#todoapp {
  background: #fff;
  margin: 180px 0 40px 0;
  position: relative;
  box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.2), 0 25px 50px 0 rgba(0, 0, 0, 0.1);
}

#todoapp input::-webkit-input-placeholder {
  font-style: italic;
  font-weight: 300;
  color: #e6e6e6;
}

#todoapp input::-moz-placeholder {
  font-style: italic;
  font-weight: 300;
  color: #e6e6e6;
}

#todoapp input::input-placeholder {
  font-style: italic;
  font-weight: 300;
  color: gray;
}

#todoapp h1 {
  position: absolute;
  top: -160px;
  width: 100%;
  font-size: 60px;
  font-weight: 100;
  text-align: center;
  color: rgba(175, 47, 47, .8);
  -webkit-text-rendering: optimizeLegibility;
  -moz-text-rendering: optimizeLegibility;
  text-rendering: optimizeLegibility;
}

.new-todo,
.edit {
  position: relative;
  margin: 0;
  width: 100%;
  font-size: 24px;
  font-family: inherit;
  font-weight: inherit;
  line-height: 1.4em;
  border: 0;
  color: inherit;
  padding: 6px;
  border: 1px solid #999;
  box-shadow: inset 0 -1px 5px 0 rgba(0, 0, 0, 0.2);
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.new-todo {
  padding: 16px;
  border: none;
  background: rgba(0, 0, 0, 0.003);
  box-shadow: inset 0 -2px 1px rgba(0, 0, 0, 0.03);
}

.main {
  position: relative;
  z-index: 2;
  border-top: 1px solid #e6e6e6;
}

.toggle-all {
  width: 1px;
  height: 1px;
  border: none; /* Mobile Safari */
  opacity: 0;
  position: absolute;
  right: 100%;
  bottom: 100%;
}

.toggle-all   label {
  width: 60px;
  height: 34px;
  font-size: 0;
  position: absolute;
  top: -52px;
  left: -13px;
  -webkit-transform: rotate(90deg);
  transform: rotate(90deg);
}

.toggle-all   label:before {
  content: "❯";
  font-size: 22px;
  color: #e6e6e6;
  padding: 10px 27px 10px 27px;
}

.toggle-all:checked   label:before {
  color: #737373;
}

.todo-list {
  margin: 0;
  padding: 0;
  list-style: none;
  max-height: 420px;
  overflow: auto;
}

.todo-list li {
  position: relative;
  font-size: 24px;
  border-bottom: 1px solid #ededed;
  height: 60px;
  box-sizing: border-box;
}

.todo-list li:last-child {
  border-bottom: none;
}

.todo-list .view .index {
  position: absolute;
  color: gray;
  left: 10px;
  top: 20px;
  font-size: 16px;
}

.todo-list li .toggle {
  text-align: center;
  width: 40px;
  /* auto, since non-WebKit browsers doesn't support input styling */
  height: auto;
  position: absolute;
  top: 0;
  bottom: 0;
  margin: auto 0;
  border: none; /* Mobile Safari */
  -webkit-appearance: none;
  appearance: none;
}

.todo-list li .toggle {
  opacity: 0;
}

.todo-list li .toggle   label {
  /*
		Firefox requires `#` to be escaped - https://bugzilla.mozilla.org/show_bug.cgi?id=922433
		IE and Edge requires *everything* to be escaped to render, so we do that instead of just the `#` - https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/7157459/
	*/
  background-image: url("data:image/svg xml;utf8,");
  background-repeat: no-repeat;
  background-position: center left;
}

.todo-list li .toggle:checked   label {
  background-image: url("data:image/svg xml;utf8,");
}

.todo-list li label {
  word-break: break-all;
  padding: 15px 15px 15px 60px;
  display: block;
  line-height: 1.2;
  transition: color 0.4s;
}

.todo-list li.completed label {
  color: #d9d9d9;
  text-decoration: line-through;
}

.todo-list li .destroy {
  display: none;
  position: absolute;
  top: 0;
  right: 10px;
  bottom: 0;
  width: 40px;
  height: 40px;
  margin: auto 0;
  font-size: 30px;
  color: #cc9a9a;
  margin-bottom: 11px;
  transition: color 0.2s ease-out;
}

.todo-list li .destroy:hover {
  color: #af5b5e;
}

.todo-list li .destroy:after {
  content: "×";
}

.todo-list li:hover .destroy {
  display: block;
}

.todo-list li .edit {
  display: none;
}

.todo-list li.editing:last-child {
  margin-bottom: -1px;
}

.footer {
  color: #777;
  padding: 10px 15px;
  height: 20px;
  text-align: center;
  border-top: 1px solid #e6e6e6;
}

.footer:before {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 50px;
  overflow: hidden;
  box-shadow: 0 1px 1px rgba(0, 0, 0, 0.2), 0 8px 0 -3px #f6f6f6,
    0 9px 1px -3px rgba(0, 0, 0, 0.2), 0 16px 0 -6px #f6f6f6,
    0 17px 2px -6px rgba(0, 0, 0, 0.2);
}

.todo-count {
  float: left;
  text-align: left;
}

.todo-count strong {
  font-weight: 300;
}

.filters {
  margin: 0;
  padding: 0;
  list-style: none;
  position: absolute;
  right: 0;
  left: 0;
}

.filters li {
  display: inline;
}

.filters li a {
  color: inherit;
  margin: 3px;
  padding: 3px 7px;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 3px;
}

.filters li a:hover {
  border-color: rgba(175, 47, 47, 0.1);
}

.filters li a.selected {
  border-color: rgba(175, 47, 47, 0.2);
}

.clear-completed,
html .clear-completed:active {
  float: right;
  position: relative;
  line-height: 20px;
  text-decoration: none;
  cursor: pointer;
}

.clear-completed:hover {
  text-decoration: underline;
}

.info {
  margin: 50px auto 0;
  color: #bfbfbf;
  font-size: 15px;
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
  text-align: center;
}

.info p {
  line-height: 1;
}

.info a {
  color: inherit;
  text-decoration: none;
  font-weight: 400;
}

.info a:hover {
  text-decoration: underline;
}

/*
	Hack to remove background from Mobile Safari.
	Can't use it globally since it destroys checkboxes in Firefox
*/
@media screen and (-webkit-min-device-pixel-ratio: 0) {
  .toggle-all,
  .todo-list li .toggle {
    background: none;
  }

  .todo-list li .toggle {
    height: 40px;
  }
}

@media (max-width: 430px) {
  .footer {
    height: 50px;
  }

  .filters {
    bottom: 10px;
  }
}

效果展示:

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