vue动画

1、效果图

 2、使用过渡类名

　　1、使用动画的步骤

把需要添加动画的元素通过<transition></transition>标签包裹起来

2、编写相应的样式

1. 1. .v-enter
   2. .v-enter-active
   3. .v-enter-to
   4. .v-leave
   5. .v-leave-active
   6. .v-leave-to

在transition上加个appear

3、使用过渡类名

  .v-enter {
            opacity: 0;
            transform: translateX(-100%);
        }

        .v-enter-active,
        .v-leave-active {
            transition: all 2s ease;
        }

        .v-enter-to,
        .v-leave {
            opacity: 1;
            transform: translateX(0);
        }

        .v-leave-to {
            opacity: 0;
            transform: translateX(100%);
        }

        .new-enter {
            opacity: 0;
            transform: scale(4);
        }

        .new-enter-active,
        .new-leave-active {
            transition: all 2s ease;
        }

        .new-enter-to,
        .new-leave {
            opacity: 1;
            transform: scale(1);
        }

        .new-leave-to {
            opacity: 0;
            transform: scale(4);
        }
    </style>

    <div id='app'>
        <transition duration="3000" appear>
            <div v-show="flag">vue简单动画效果</div>
        </transition>
        <button @click="flag=!flag">点击</button>

        <transition duration="3000" name="new">
            <div style=" 70px;height: 70px;background: aquamarine;" v-show="newFlag">vue简单动画效果</div>
        </transition>
        <button @click="newFlag=!newFlag">点击</button>

    </div>
    <script>
        const vm = new Vue({
            el: '#app',
            data: {
                flag: true,
                newFlag: false,
            }
        })
    </script>

4、使用第三方css动画库

1、导入动画类库：

  <link
    rel="stylesheet"
    href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/4.1.0/animate.min.css"
  />

　　2、给transition上加上进场和离场的动画效果

<transition appear enter-active-class="animate__animated  animate__bounceInLeft"
    leave-active-class="animate__animated animate__backOutRight"
>
    <div v-if="flag">欢迎来到天亮教育</div>        
</transition>

1. enter-active-class
2. leave-active-class

　　3、注意事项，使用animate的时候前面需要加上animate__animated

　　4、duration：指定动画的激活时长，就是指定动画激活的样式在标签上的持续时间

5、进场离场相同

<transition appear enter-active-class="animate__animated  animate__bounceInLeft"
            leave-active-class="animate__animated animate__backOutRight"
            duration="1000"
>

　　6、进场离场不同

<transition appear enter-active-class="animate__animated  animate__bounceInLeft"
            leave-active-class="animate__animated animate__backOutRight"
            :duration="{enter:3000,leave:1000}"
>

　　7、案例

 <div id='app'>
    <transition enter-active-class="animate__animated animate__backInDown"
    leave-active-class="animate__animated animate__backOutDown">
        <div v-show="flag">vue简单动画效果</div>
    </transition>
    <button @click="flag=!flag">点击</button>

</div>
<script>
    const vm = new Vue({
        el: '#app',
        data: {
            flag: false,
        }
    })
</script>

5、使用动画钩子函数

　　1、before-enter

　　　　1、el

　　2、enter

　　　　1、el

　　　　2、done 结束函数，调用它之后

　　3、after-enter

　　　　1、el

    <style>
        .show {
             40px;
            height: 40px;
            border-radius: 50%;
            background: mediumorchid;
        }
    </style>

    <div id='app'>
        <button @click="flag = !flag">按钮</button>
        <transition @before-enter="beforeEnter" @enter="enter" @after-enter="afterEnter">
            <div v-if="flag" class="show"></div>
        </transition>

    </div>
    <script>
        const vm = new Vue({
            el: '#app',
            data: {
                flag: false,
            },
            methods: {
                 beforeEnter(el) {
                    el.style.transform = "translate(0,0)"
                },
                enter(el, done) {
                    el.offsetHeight;
                    el.style.transition = "all 1s ease";   
                    el.style.transform = "translate(300px,500px)"
                    done()
                },
                afterEnter(el) {
                    setTimeout(() => {
                        this.flag = false;
                    }, 1000)
                }
            }
        })
    </script>

6、v-for的列表过渡

　　1、使用方法

　　1、transition-group替代transition

　　2、v-for的每一项必须要加上key

　　3、通过tag设置标签

　　4、其他都和transition用法一样

2、列表的平滑切换

　　通过v-move结合v-leave-active让列表切换更平滑

.v-move{
   transition: all .5s ease;
}
.v-leave-active {
  position: absolute;
}

　　3、案例

 <style>
        .v-enter,
        .v-leave-to {
            opacity: 0;
            transform: translateY(100%);
        }

        .v-enter-active {
            transition: all 0.5s ease;
        }

        .v-leave,
        .v-enter-to {
            opacity: 1;
            transform: translateY(0);
        }

        .v-move {
            transition: all 0.5s ease;
        }

        .v-leave-active {
            position: absolute;
        }
    </style>

    <div id='app'>
        <button @click='reverse'>翻转</button>
        <transition-group tag="ul" appear>
            <li v-for="(item, index) in list" :key="item.id" @click="del(index)">{{item.name}}</li>
        </transition-group>

    </div>
    <script>
        const vm = new Vue({
            el: '#app',
            data: {
                list: [
                    {
                        id: 1,
                        name: "张三",
                    },
                    {
                        id: 2,
                        name: "李四",
                    },
                    {
                        id: 3,
                        name: "王五",
                    }
                ]
            },
            methods: {
                reverse() {
                    this.list = this.list.reverse();
                },
                del(index) {
                    this.list.splice(index, 1);
                }
            }
        })
    </script>