el-upload实现只上传一个文件且再次上传会覆盖前面的文件

:before-remove="()=>false"，阻止delete删除附件

<div class="upload-file">
    <el-upload
        ref="upload"
        :on-error="onError"
        :file-list="fileList"
        :auto-upload="false"
        :before-remove="()=>false"
        :on-change="handleChange">
        <el-button slot="trigger" size="small" type="primary">选取文件</el-button>
    </el-upload>
</div>

判断，只上传一个附件

handleChange(file, fileList) {
    if (fileList&&fileList.length>=2) {
        fileList.shift();
    }

    this.fileData = file;
    this.$refs.upload.submit();
},

隐藏删除按钮

.upload-file .el-upload-list .el-upload-list__item:hover .el-icon-close {
    display: none;
}