vue2 父子组件传参 回调函数使用

关键点：
父组件给子组件动态传参使用​​​v-bind:​​​属性key（多个单词用下划线拼接）
子组件接收父组件传参参数使用 ​​​props​​标签，+属性key多个单词用驼峰形式拼接）

子组件定义回调父组件函数
子组件：
v-on:change="uploadFile()

父组件：
:after-upload=“afterUpload”
然后定一个afterUpload(resp)方法接收子组件传过来的值

<div class="col-sm-10">
                  <file :text="'上传头像1'"
                        :input-id="'image-upload'"
                        :suffixs="[ ['jpg', 'jpeg', 'png']]"
                        :after-upload="afterUpload">
                  </file>
<script>
import File from "../../components/file";

export default {
  components: {File},
  name: "business-teacher",
  data: function () {
  },
  mounted: function () {
  },
  methods: {
    afterUpload(resp) {
      let _this = this
      let image = resp.content;
      _this.teacher.image = image
    }
  }
}
</script>

子组件

<template>
  <div>
    <button type="button" v-on:click="selectFile()" class="btn btn-white btn-default btn-round">
      <i class="ace-icon fa fa-upload"></i>
      {{ text }}
    </button>
    <input class="hidden" type="file"
           ref="file"
           v-on:change="uploadFile()"
           v-bind:id="inputId+'-input'">
  </div>
</template>

<script>
export default {
  name: 'file',
  props: {
    text: {
      default: "上传文件"
    },
    inputId: {
      default: "file-upload"
    },
    suffixs: {
      default: []
    },
    afterUpload: {
      type: Function,
      default: null
    },
  },
  data: function () {
    return {}
  },
  methods: {

    uploadFile() {
      let _this = this;
      let formData = new window.FormData();
      let file = _this.$refs.file.files[0];

      // 判断文件格式
      let suffixs = _this.suffixs;
      let fileName = file.name;
      let suffix = fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length).toLowerCase();
      let validateSuffix = false;
      for (let i = 0; i < suffixs.length; i++) {
        let suffix2 = suffixs[i] += ''
        if (suffix2.toLowerCase() === suffix) {
          validateSuffix = true;
          break;
        }
      }

      if (!validateSuffix) {
        Toast.warning("文件格式不正确，只支持上传：" + suffixs.join(","));

        //解决 同一个文件上传2次或者大于2次，不会发生变化
        $("#" + _this.inputId + "-input").val("");
        return
      }

      // key："file"必须和后端controller参数名一致
      formData.append("file", file);
      Loading.show()
      _this.$api.post(process.env.VUE_APP_SERVER + '/file/admin/upload', formData).then((response) => {
        Loading.hide()

        let resp = response.data
        console.log("上传文件成功：", resp)

        //回调父组件函数
        _this.afterUpload(resp)

        //解决 同一个文件上传2次或者大于3次，不会发生变化
        $("#" + _this.inputId + "-input").val("");
      })
    },

    selectFile() {
      let _this = this
      // console.log("_this.inputId",_this.inputId)
      $("#" + _this.inputId + "-input").trigger("click");
    }
  },
}
</script>

<style scoped>
</style>