单击“编辑”按钮时，我发现我的ID翻倍

Question

我创建我的分支，在这里我选择下拉列表来选择我的公司，在下拉列表中绑定公司ID和公司名称。当我创建编辑功能时，我填写了所有必填字段，当我单击编辑按钮时，我发现我的com_id双，例如：04是我的真实ID，我得到“ 0404”，现在我该如何解决？

这是我的控制器，

public ActionResult Edit(string id)
    {


        Branch model = new Branch();
        var br = erkDB.m_br.FirstOrDefault(x => x.br_id == id);
        model.br_id = id;
        model.br_nam = br.br_nam;
        model.br_add = br.br_add;
        model.br_eml = br.br_eml;
        model.br_fax = br.br_fax;
        model.br_mob = br.br_mob;
        model.br_typ = br.br_typ;
        model.com_id = br.com_id;
        var com = erkDB.m_com.ToList();
        foreach (var item in com)
        {
            Company company = new Company();
            company.com_nam = item.com_nam;
            company.com_id = item.com_id;
            model.comModel.Add(company);
        }



        return View("Create", model);

    }
    [HttpPost]
    public ActionResult Edit(Branch model)
    {
        if (ModelState.IsValid)
        {

            var br = erkDB.m_br.FirstOrDefault(x => x.br_id == model.br_id);
            var temp = Request.Form["com_id"].ToString();
            string strNew = temp.Replace(",","");
             //br.br_id = br;
            br.br_nam = model.br_nam;
            br.br_pho = model.br_pho;
            br.com_id = strNew;
            br.br_web = model.br_web;
            br.br_mob = model.br_mob;
            br.br_eml = model.br_eml;
            br.br_fax = model.br_fax;

            br.br_typ = model.br_typ;


            // mvcdb.m_com.Add(company);
            erkDB.SaveChanges();
            return RedirectToAction("Index");
        }


        return View("Create", model);

    }