vue 实现编辑头图像用到cropperjs、axios、dom操作、vant和input标签将本地图片地址转换成img标签能够识别的路径window.URL.createObjectUR

1、首先安装vant、axios、cropperjs

npm i vant
npm install axios
npm install cropperjs

2、在main.js中导入并挂载

import Vant from 'vant'
import 'vant/lib/index.css';

createApp(App).use(Vant)

3、app.vue中的内容如下：

<template>
  <input type="file" ref="choose_img" name="" id="choose_img" @change="getFileNameToText($event)" hidden="">
  <van-cell title="点击编辑头像" @click="openInput">
    <template #right-icon>
      <span>
        <img v-if="myDefaultPath" class="avater" :src="myDefaultPath" alt="">
      span>
    template>
  van-cell>
  <van-popup
      @opened="openPop"
      v-model:show="showBottom"
      position="bottom"
      :style="{ height: '100%' }"
  >
    <div class="wrapper" v-if="showBottom">
      <img ref="cropImage" id="backgroundImage" :src="image_path" alt="">
    div>
    <div class="footer">
      <van-button class="cancel" @click="cancelCrop" type="default">取消van-button>
      <van-button class="sure" @click="sureCrop" type="default">确认van-button>
    div>
  van-popup>
template>
<script setup>
//导入cropper内容
import 'cropperjs/dist/cropper.css';
import Cropper from 'cropperjs';


import {onMounted, ref} from "vue";
import axios from "axios";
const input_label = ref(null)
const image = ref(null)
const cropImage = ref(null)
const image_path = ref('')
const showBottom = ref(false)
const myDefaultPath = ref('')
const cropper = ref(null)
// const choose_img = ref(null)

// 这个是当弹框动画完成后会自动执行所以这时就有dom了
const openPop = ()=>{
  image.value = document.getElementById('backgroundImage');
  cropper.value = new Cropper(image.value, {
    viewMode: 1,
    dragMode: 'move',
    aspectRatio: 1, /// //裁剪图片比列
    // autoCropArea: 1,
    cropBoxMovable: false, /// ///截图区域移动
    cropBoxResizable: false, /// //截图区域缩放
    background: false/// //默认马赛克背景
  })
}

const openInput = () => {
  // 给input文本框一个点击事件
  input_label.value.click()
}
const getFileNameToText = (e)=>{
  // 将本地打开的文件url转变成img标签能够识别的url
  image_path.value = window.URL.createObjectURL(input_label.value.files[0])
  showBottom.value = true
}
const cancelCrop = ()=>{
  // 他的作用是将input的输入的值改变一下
  // 如果不改变则下次再次点击同一个文件不会出发change事件
  input_label.value.value = ''
  // 关闭弹框
  showBottom.value = false
}
const sureCrop = ()=>{
  cropper.value.getCroppedCanvas().toBlob(blob => {
    console.log('blob', blob)
    const formData = new FormData();
    formData.append('photo', blob)
    axios({
      url:'http://toutiao.itheima.net/v1_0/user/photo',
      method: 'patch',
      headers:{
        'Authorization': 'Bearer be4168af-bb95-4914-bc98-bdd61fb78e8e'
      },
      data:formData
    }).then(res=>{
      myDefaultPath.value=res.data.data.photo
      // 作用还是改变一下值
      input_label.value.value = ''
      // 关闭弹框
      showBottom.value = false
    })

  })
}

onMounted(()=>{
  // 只有挂载后才有dom
  input_label.value = document.getElementById('choose_img')

})
script>

<style scoped lang="less">
.avater{
  width: 50px;
  height: 50px;
  border-radius: 25px;
}
#backgroundImage{
  display: block;
  max-width: 100%;
}
.wrapper{
  height: 100%;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: pink;
}
.footer{
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  .cancel, .sure{
    width: 100px;
    height: 50px;
  }
  .cancel{
    margin-left: 20px;
  }
  .sure{
    margin-right: 20px;
  }
}
style>

4、显示的效果如下：

点击进入corpperjs官网