MVC列表框選定值

Question

新來的MVC和＃2很抱歉因沒有足夠的聲譽，發佈圖片...

試圖使具有預選值

我的SQL數據庫列表框： http://i.imgur.com/bcdXyqE.png

我的實體框架 http://i.imgur.com/wYWXuAq.png

我的控制器

public ActionResult AccessRights(int id) 
    { 
     var user = db.User.Find(id); 

     var roles = db.Role; 

     var newList = new List<SelectListItem>(); 

     foreach (var role in roles) 
     { 
      newList.Add(
       new SelectListItem() 
       { 
        Value = role.Id.ToString(), 
        Text = role.RoleName, 
        Selected = user.Role.Contains(role) 
       } 
      ); 
     } 

     ViewBag.x = new SelectList(newList, "Value", "Text"); 

     ViewBag.Roles = new SelectList(db.Role, "Id", "RoleName", user.Role); 

     return View(user); 
    } 

我查看

<p>try1:</p> 
@Html.ListBox("Roles", null, new { @class = "form-control", @size = 6, @style = "height: initial" }) 
<p>try2:</p> 
@Html.ListBox("x", null, new { @size = 6, @style = "height: initial" }) 

非2次的嘗試使得具有預選值？

Answer 1

讓它工作。

public ActionResult AccessRights(int id) 
    { 
     var user = db.User.Find(id); 

     IEnumerable<SelectListItem> roles = db.Role.Select(c => new SelectListItem{ Value = c.Id.ToString(), Text = c.RoleName, Selected = true}); 
     var rolesSelected = new int[user.Role.Count]; 
     var i = 0; 
     foreach (var role in user.Role) 
     { 
      rolesSelected[i] = role.Id; 
      i++; 
     } 

     ViewBag.Roles = roles.ToList(); 
     ViewBag.RolesSelected = rolesSelected; 

     return View(user); 
    } 

@Html.ListBox("RolesSelect", new MultiSelectList(ViewBag.Roles, "Value", "Text", ViewBag.RolesSelected), new { @class = "form-control", @size = 6, @style = "height: initial" })