实现记住密码的操作，如下图所示

html部分

        <el-form-item style="margin-top:-10px;margin-bottom:-5px;" >
           <el-checkbox v-model="checked" style="color:#a0a0a0;margin-top:-10px;">记住密码</el-checkbox>
        </el-form-item>
        <el-form-item style="margin-top:-10px;margin-bottom:-5px;" >
           <el-checkbox v-model="checked" style="color:#a0a0a0;margin-top:-10px;">记住密码</el-checkbox>
        </el-form-item>

data部分

      checked: true,

methods部分
点击登录时

 submitForm(userInfo) {
      const self = this;
      if (self.checked == true) {
        // console.log("checked == true");
        //传入账号名，密码，和保存天数3个参数
        self.setCookie(self.userInfo.user, self.userInfo.pass, 7);
      } else {
        // console.log("清空Cookie");
        //清空Cookie
        self.clearCookie();
      }
      }

设置cookie

    //设置cookie
    setCookie(c_name, c_pwd, exdays) {
      var exdate = new Date(); //获取时间
      exdate.setTime(exdate.getTime() + 24 * 60 * 60 * 1000 * exdays); //保存的天数
      //字符串拼接cookie
      window.document.cookie =
        "userName" + "=" + c_name + ";path=/;expires=" + exdate.toGMTString();
      window.document.cookie =
        "userPwd" + "=" + c_pwd + ";path=/;expires=" + exdate.toGMTString();
    },

读取cookie

    getCookie: function() {
      if (document.cookie.length > 0) {
        var arr = document.cookie.split("; "); //这里显示的格式需要切割一下自己可输出看下
        for (var i = 0; i < arr.length; i++) {
          var arr2 = arr[i].split("="); //再次切割
          //判断查找相对应的值
          if (arr2[0] == "userName") {
            this.userInfo.user = arr2[1]; //保存到保存数据的地方
          } else if (arr2[0] == "userPwd") {
            this.userInfo.pass = arr2[1];
          }
        }
      }
    },

清除cookie

    //清除cookie
    clearCookie: function() {
      this.setCookie("", "", -1); //修改2值都为空，天数为负1天就好了
    },

在mounted里面获取cookie

 mounted() {
    this.getCookie();
  }

本文大部分参考 肖敏 的技术博客 https://www.cnblogs.com/nxmin/p/8386031.html