我有一个数据库表，记录了允许用户访问的出版物。该表非常简单 - 它只存储用户ID /发布ID对：
CREATE TABLE UserPublication (UserId INTEGER, PublicationID INTEGER)
存在给定用户的记录＆amp;发布意味着用户有权访问;没有记录意味着无法访问。
我想向管理员用户提供一个简单的屏幕，允许他们配置用户可以访问的出版物。我想为每个可能的出版物显示一个复选框，并检查用户当前可以访问的出版物。然后，管理员用户可以检查或取消检查任意数量的出版物并提交表格。
有各种各样的出版物类型，我想将类似类型的出版物组合在一起 - 所以我确实需要控制出版物的呈现方式（我不想只是有一个单一的列表）。
我的视图模型显然需要有一个所有出版物的列表（因为无论当前选择如何，我都需要显示它们），而且我还需要用户当前有权访问的出版物列表。 （我不确定我是否会更好地使用单个列表，其中每个项目包含发布ID和是/否字段？）。
但就我而言。我真的不知道如何将它绑定到一些复选框。我从哪里开始？
答案 0 :(得分：19)
您的问题的Linq to SQL 模型看起来像这样：
alt text http://i39.tinypic.com/m78d1y.jpg
首先，我们需要在数据模型中使用一些辅助对象：
namespace SelectProject.Models
{
public class UserPublicationSelector
{
public int UserPublicationID { get; set; }
public int UserID { get; set; }
public int PublicationID { get; set; }
public string PublicationName { get; set; }
public bool IsSelected { get; set; }
}
public class UserPublicationSelectViewModel
{
public User User { get; set; }
public IQueryable Selections { get; set; }
}
}
现在让我们创建一个如下所示的存储库：
public class Repository
{
DataContext dc = new DataContext();
public User GetUser(int userID)
{
return dc.Users.FirstOrDefault(u => u.UserID == userID);
}
public IQueryable GetUserPublications(int userID)
{
return from p in dc.Publications
join up in dc.UserPublications on p.PublicationID equals up.PublicationID
where up.UserID == userID
orderby p.PublicationName
select p;
}
public IQueryable GetUserPublicationSelectors(int userID)
{
return from p in dc.Publications
join up in dc.UserPublications on p.PublicationID equals up.PublicationID into selected
from s in selected.DefaultIfEmpty()
orderby p.PublicationName
select new UserPublicationSelector
{
UserPublicationID = (int?)s.UserPublicationID ?? 0,
UserID = userID,
PublicationID = p.PublicationID,
PublicationName = p.PublicationName,
IsSelected = s.UserID != null
};
}
public void UpdateUserPublications(UserPublicationSelector[] selections)
{
// Insert records for new selections...
foreach (UserPublicationSelector selection in selections.Where(s => s.IsSelected == true))
{
// ...where records do not yet exist in database.
if (selection.UserPublicationID == 0)
{
UserPublication up = new UserPublication
{
UserID = selection.UserID,
PublicationID = selection.PublicationID,
};
dc.UserPublications.InsertOnSubmit(up);
}
}
// Delete records for unselected items...
foreach (UserPublicationSelector selection in selections.Where(s => s.IsSelected == false))
{
// ...where record exists in database.
if (selection.UserPublicationID > 0)
{
UserPublication up = dc.UserPublications.FirstOrDefault(s => s.UserPublicationID == selection.UserPublicationID);
if (up.UserID == selection.UserID && up.PublicationID == selection.PublicationID)
dc.UserPublications.DeleteOnSubmit(up);
}
}
// Update the database
dc.SubmitChanges();
}
}
控制器，如下所示：
public class PublicationController : Controller
{
Repository repository = new Repository();
public ActionResult Index(int id)
{
User user = repository.GetUser(id);
var publications = repository.GetUserPublications(id);
ViewData["UserName"] = user.UserName;
ViewData["UserID"] = user.UserID;
return View("Index", publications);
}
[AcceptVerbs(HttpVerbs.Get)]
public ActionResult Select(int id)
{
var viewModel = new UserPublicationSelectViewModel()
{
User = repository.GetUser(id),
Selections = repository.GetUserPublicationSelectors(id)
};
return View("Select", viewModel);
}
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Select(int userID, UserPublicationSelector[] selections)
{
repository.UpdateUserPublications(selections);
return RedirectToAction("Index", new { id = userID });
}
}
索引视图如下所示：
<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<IEnumerable<Publication>>" %>
<%@ Import Namespace="SelectProject.Models" %>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
List of Selected Publications for User
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Publications for <%= ViewData["UserName"] %></h2>
<table id="MyTable" style="width: 100%">
<thead>
<tr>
<th>
Publication Name
</th>
</tr>
</thead>
<tbody>
<% int i = 0;
foreach (Publication item in Model)
{ %>
<tr id="row<%= i.ToString() %>">
<td>
<%= Html.Encode(item.PublicationName)%>
</td>
</tr>
<% i++;
} %>
</tbody>
</table>
<p>
<%= Html.ActionLink("Edit Selections", "Select", new { id = ViewData["UserID"] })%>
</p>
</asp:Content>
选择视图如下所示：
<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<UserPublicationSelectViewModel>" %>
<%@ Import Namespace="SelectProject.Models" %>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Select Publications
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Select Publications for <%= Model.User.UserName %></h2>
<% using (Html.BeginForm())
{ %>
<table id="MyTable" style="width: 100%">
<thead>
<tr>
<th style="width: 50px; text-align:center">
<input type="checkbox" id="SelectAll" />
</th>
<th>
Publication Name
</th>
</tr>
</thead>
<tbody>
<% int i = 0;
foreach (UserPublicationSelector item in Model.Selections)
{ %>
<tr id="row<%= i.ToString() %>">
<td align="center" style="padding: 0 0 0 0">
<%= Html.CheckBox("selections[" + i.ToString() + "].IsSelected", item.IsSelected)%>
<%= Html.Hidden("selections[" + i.ToString() + "].UserPublicationID", item.UserPublicationID)%>
<%= Html.Hidden("selections[" + i.ToString() + "].UserID", Model.User.UserID)%>
<%= Html.Hidden("selections[" + i.ToString() + "].PublicationID", item.PublicationID)%>
</td>
<td>
<%= Html.Encode(item.PublicationName)%>
</td>
</tr>
<% i++;
} %>
</tbody>
</table>
<p>
<%= Html.Hidden("userID", Model.User.UserID) %>
<input type="submit" value="save" />
</p>
<% } // End Form %>
<script src="../../Scripts/jquery-1.4.1.js" type="text/javascript"></script>
<script type="text/javascript">
// Select All Checkboxes
$(document).ready(function() {
$('#SelectAll').click(function() {
var newValue = this.checked;
$('input:checkbox').not('input:hidden').each(function() {
this.checked = newValue;
});
});
});
</script>
</asp:Content>
以下是一些屏幕截图。
alt text http://i43.tinypic.com/2yl07kw.jpg
alt text http://i44.tinypic.com/mhulua.jpg
左上角的复选框是全选/选择无复选框。
