Upload pictures in element, upload address folder, how to write, control the upload image address in the foreground and background?

< el-form class= "from-1" ref= "form": model= "form": rules= "rules" label-width= "80px" style= "width:100%; height: 380px;" >

      <el-form class="from_n1" style="width:940px; margin:auto;">
        <div id="wen" >:jpg,png,jpeg,30M</div>
       <el-form-item label=":" prop="idzhengpic" class="dt1" style=" float:left; width:47%; margin:0px 1% 0px 2%;" >
        <el-upload class="avatar-uploader"  action="" :show-file-list="false" :on-success="handleAvatarSuccess" :before-upload="beforeAvatarUpload" >
          <img v-if="idzhengpic" :src="idzhengpic" class="avatar" >
          <i v-else class="el-icon-plus avatar-uploader-icon"></i>
        </el-upload>
      </el-form-item>