File input on change in vue.js

问题

Using plain HTML/JS, it is possible to view the JavaScript File objects of selected files for an input element like so:

<input type="file" id="input" multiple onchange="handleFiles(this.files)">

However, when converting it to the 'Vue' way it doesn't seem to work as intend and simply returns undefined instead of returning an Array of File objects.

This is how it looks in my Vue template:

<input type="file" id="file" class="custom-file-input" 
  v-on:change="previewFiles(this.files)" multiple>

Where the previewFiles function is simply the following (located in methods):

  methods: {
    previewFiles: function(files) {
      console.log(files)
    }
  }

Is there an alternate/correct way of doing this? Thanks

回答1:

Another solution:

<input type="file" @change="previewFiles" multiple>

methods: {
   previewFiles(event) {
      console.log(event.target.files);
   }
}

回答2:

Try this.

<input type="file" id="file" ref="myFiles" class="custom-file-input" 
  @change="previewFiles" multiple>

and in your component options:

data() {
  return {
    files: [],
  }
},
methods: {
  previewFiles() {
    this.files = this.$refs.myFiles.files
  }
}

回答3:

For all the TS-Users out there:

<template>
<input ref="upload"
       type="file"
       name="file-upload"
       multiple=""
       accept="image/jpeg, image/png"
       @change="onUploadFiles">
</template>

import { Component, Prop, Vue } from 'vue-property-decorator';

@Component({ components: {} })
export default class MediaEdit extends Vue {

private onUploadFiles(event: InputEvent): void {
    const files: ReadonlyArray<File> = [...(this.upload.files ? this.upload.files : [])];

        files.forEach((file) => {
            console.log(`File: ${file.name}`);
        });
    }

    /** Upload element */
    private get upload(): HTMLInputElement {
        return this.$refs.upload as HTMLInputElement;
    }
}

回答4:

<form ref="form">
   <input type="file" @change="previewFiles" multiple tabindex="-1">
</form>

methods: {
   previewFiles(event) {

      // process your files, read as DataUrl or upload...
      console.log(event.target.files);

      // if you need to re-use field or drop the same files multiple times
      this.$refs.form.reset() 

   }
}

On Safari, you might face an issue when @input/change event won't fire.

tabindex="-1" - it's a magic trick to make it works on Safari (13.0.2)

来源：https://stackoverflow.com/questions/45179061/file-input-on-change-in-vue-js

标签

javascript

Vue.js

vuejs2

vue-component