Q:

Data is displayed in the vue console but not returned to the web page

FileUpload.vue
<template>
<div>
   <vue-dropzone
           :options="dropzoneOptions">      
      <div class="dropzone-custom-content" id="custom">
        <h3 class="dropzone-custom-title">Drag & Drop</h3>       
      </div>
   </vue-dropzone>
    <div>
        Content: {{testmsg}}
    </div>
</div>
</template>

<script>
import vue2Dropzone from "vue2-dropzone";
import 'vue2-dropzone/dist/vue2Dropzone.min.css'
export default {
    components: {
        vueDropzone: vue2Dropzone,
    },
    data() {
        return {
            dropzoneOptions: {
                url: 'http://localhost:5000/',
                method: "post",
                maxFiles: 1,
                thumbnailWidth: 300,
                maxFilesize: 500,
                success: function (file, responejson) {
                    this.msg = responejson
                    console.log(this.msg)
                    this.testmsg='Hi'
                    console.log(this.testmsg)
                },

console.log(this.testmsg)=>Hi
After uploading an image, the value Hi does not appear on the web.
Image attached.
The console window results and scenes do not appear on the web.

This is the console window result.

Content: No value appears.

A:

There is no testmsg property in data. It should be:
data: () => ({
    testmsg: '',
    dropzoneOptions: {
          // rest of your code
     }
})

