elementui表单验证图片上传为必填

1.form表单 上传自己看着写

 <el-form ref="formOut" :model="formData" :rules="formRules" label-width="120px">
     <el-form-item label="图标" prop="img">
       <div style="display: flex">
         <el-upload class="upload-demo" :action="url + '/file/put-file'" :on-success="(res) => {onSuccess(res, 'formData');}" :limit="1" :file-list="fileList" :show-file-list="false" ref="uploadImg1">
           <div v-if="formData.img">
             <img :src="formData.img" alt="" style="width: 50px; height: 50px" />
             <i class="el-icon-delete iconClass_del" @click.stop="delPic('formData')"></i>
           </div>
           <el-button v-else size="small" type="primary">点击上传</el-button>
         </el-upload>
       </div>
     </el-form-item>
 </el-form>

2.rules验证规则

 formRules: {
     img: [
       {
            required: true,
            validator: this.fileMustUpload,
            trigger: "change",
        },
      ],
 }

3.自定义验证方法

    fileMustUpload(rule, value, callback) {
      if (this.formData.img == null) {
        // 未上传文件
        callback("请上传图标");
      }
      callback();//不要忘记写这个callback
    },