小编Ale*_*ekz的帖子

正如标题所说,我正在寻找这项任务的一些帮助,我已经阅读了很多关于它的教程,但没有一个可以解决我的问题,即如何dropdownlistfor从数据库加载.到目前为止,我得到了以下代码:

**LNClientes():**

public List<ENDistrito> DistritoListar()
{
    return new ADClientes().DistritoListar();
}

**ADClientes():**

public List<ENDistrito> DistritoListar()
        {
            Database oDatabase =                      DatabaseFactory.CreateDatabase(ConfigurationManager.AppSettings["conexionBD"]);
            DbCommand odbcommand = oDatabase.GetStoredProcCommand("USP_SEL_DISTRITOS");

            List<ENDistrito> lista = new List<ENDistrito>();
            using (IDataReader reader = oDatabase.ExecuteReader(odbcommand))
            {
                while (reader.Read())
                    lista.Add(new ENDistrito(reader));
            }
            return lista;
        }

**Controller:**

 public ActionResult Registrar()
        {
            ViewBag.Message = Resources.Language.Title_Page_MC_C;
            var ListaDistrito = new LNClientes().DistritoListar();
            ViewBag.ObtenerDistrito = new SelectList(ListaDistrito, "IdDistrito", "DescripcionDistrito");
            return View();
        }

视图:

<div class="editor-field">
            @Html.EditorFor(model => model.DistritoCliente)
            @Html.DropDownListFor(model => model.DistritoCliente,(SelectList)ViewBag.ObtenerDistrito,"--Seleccione--")
            @Html.ValidationMessageFor(model => model.DistritoCliente)
        </div>

直到这一点一切正常,当我打开表单的 …

为什么var第一种情况不改变而第二种改变？

#!/bin/bash
var=0

changeVar()
{
  var=1
}

第一种情况:

tmp=$(changeVar)
echo "var = $var"         // var = 0

第二种情况:

changeVar
echo "var = $var"         // var = 1