首先需要下载插件，不需要多说npm install vue-cropper –save;
1.自己项目对应的页面进行引入import { VueCropper } from “vue-cropper”;
2.注册组件：components: { VueCropper };
3.上传时调用该插件；我是借助elementUI的上传组件再加工处理的：
页面如下：

         <div class="home-tab-body-img">
          <div class="imgList" v-for="(item,index) in fileImgList" :key="index">
            <div class="imgList-delete" @click = "deleteImg(item)">
               <i class="el-icon-close" title="删除" ></i>
            </div>
            <img :src="getReadImg(item.filePath)" alt="" @click="handlePictureCardPreview(item.filePath)">
            <el-dialog :visible.sync="dialogVisible">
              <img width="100%" :src="getReadImg(filePathAdd)" alt="">
            </el-dialog>
          </div>
          <el-upload
          :multiple="false"
          :show-file-list="false"
          class="editor-slide-upload"
          :before-upload="beforeAvatarUploadPS"
          list-type="picture-card"
          action
          :limit="3"
          >
            <i class="el-icon-plus"></i>
            <p>(最多3张)</p>
          </el-upload>
      </div>
     
    <!-- 剪切图片的弹框-->
    <div class="upload-dialog">
        <el-dialog title="图片裁剪" :visible.sync="isShowCropper" :close-on-click-modal="false">
          <div class="vue-cropper-box">
            <div class="vue-cropper-content">
                 <vueCropper
                ref="cropper"
                :img="option.img"
                :outputSize="option.size"
                :outputType="option.outputType"
                :info="option.info"
                :full="option.full"
                :canMove="option.canMove"
                :canMoveBox="option.canMoveBox"
                :original="option.original"
                :autoCrop="option.autoCrop"
                :autoCropWidth="option.autoCropWidth"
                :autoCropHeight="option.autoCropHeight"
                :fixedBox="option.fixedBox"
                @realTime="realTime"
                @imgLoad="imgLoad"
            ></vueCropper>
            </div>
            <div class="operate-wrap">
              <div class="lf">
                <el-button type="primary" plain @click="turnLeft">左旋转</el-button>
                <el-button type="primary" plain @click="turnRight">右旋转</el-button>
                <el-button type="primary" plain @click="changeScale(1)">放大</el-button>
                <el-button type="primary" plain @click="changeScale(-1)">缩小</el-button>
                <el-button type="primary" @click="onCubeImg">上传</el-button>
              </div>
              <div class="rt">
                <el-button type="primary" @click="cancleCropper">取消</el-button>
              </div>
            </div>

          </div>
        </el-dialog>
    </div>

vuecropper的基础配置：

    //裁剪组件的基础配置option
  option: {
            img: '', // 裁剪图片的地址
            info: true, // 裁剪框的大小信息
            outputSize: 1, // 剪切后的图片质量（0.1-1）
            full: true, // 输出原图比例截图 props名full
            outputType: 'png', // 裁剪生成额图片的格式
            canMove: true,  // 能否拖动图片
            original: false,  // 上传图片是否显示原始宽高
            canMoveBox: true,  // 能否拖动截图框
            autoCrop: true, // 是否默认生成截图框
            autoCropWidth: 740, // 默认生成截图框宽度
            autoCropHeight: 400, // 默认生成截图框高度
            fixedBox: true // 截图框固定大小
  },
  //切图尺寸是固定的，想可修改可把fixedBox设置为false
  
  

借助before-upload上传时调用vuecropper插件：

 beforeAvatarUploadPS(file) {
    if(this.imgLength > 2){
      this.$message({
                type: "warning",
                message: "效果图最多上传3张"
            });
      return false
    }
    this.option.img=URL.createObjectURL(file);
            const isDWG = file.name.split('.');
    const format = isDWG[isDWG.length - 1];
    this.uploadParams.isFile="1";
        // uploadParams.file="";
            if (format !="png" && format !="jpg") {
                        this.$message.error('上传文件只能是 png或jpg 格式!');
                        return false;
    }
    this.isShowCropper = true;
    // const dialog = new Promise((resolve,reject)=>{
      
    // });

    // return dialog
},
然后我加了几个剪切的按钮进行旋转或放大，并把上传方法一并粘贴到如下：

 turnLeft() {
  this.$refs.cropper.rotateLeft();
},
turnRight() {
  this.$refs.cropper.rotateRight();
},
cancleCropper() {//取消截图
  this.isShowCropper = false;
},
changeScale(num){
    num = num || 1; 
    this.$refs.cropper.changeScale(num); 
},
imgLoad (msg) { 
    console.log('imgLoad')
    console.log(msg) 
},
 // 实时预览函数 
realTime(data) { 
    console.log('realTime')
    this.previews = data 
}, 
onCubeImg() {//剪切上传
  // 获取cropper的截图的base64 数据
  this.$refs.cropper.getCropData(data => {
    // this.fileinfo.url = data;
    
    //先将显示图片地址清空，防止重复显示
    this.option.img = "";
    //将剪裁后base64的图片转化为file格式
    let file = this.convertBase64UrlToBlob(data);
    // this.fileImg=URL.createObjectURL(file);
    var formData = new FormData();
    formData.append("file", file);
    formData.append("isFile", '1');
    projectResource.uploadImg(this.prjID,formData).then(res=>{
        if(res.result == "0"){
          this.$message({
              type: "success",
              message: "上传成功"
          });
          this.fileTypeSearch();
          this.isShowCropper = false;
          // this.fileList=[{name: 'food.jpg', url: 'https://xxx.cdn.com/xxx.jpg'}]
        }
    });
  });
},
// 将base64的图片转换为file文件
convertBase64UrlToBlob(urlData) {
  let bytes = window.atob(urlData.split(",")[1]); //去掉url的头，并转换为byte
  //处理异常,将ascii码小于0的转换为大于0
  let ab = new ArrayBuffer(bytes.length);
  let ia = new Uint8Array(ab);
  for (var i = 0; i < bytes.length; i++) {
    ia[i] = bytes.charCodeAt(i);
  }
  return new Blob([ab], { type: "image/jpeg" });
},

处理完这些你就可以看看你的也页面了

备注：vuecropper主要是
，
把需要的参数处理好，基本就算基础掌握该插件了