建立一个使用.Net 2.0 MemberShip功能的标准例程（三）——绑定访问篇

经过上一章的例子我们已经建立了一个标准的，有很多有趣（甚至有些是专业级）功能的登陆系统了。
可是我们如何管理这个系统呢？难道我们要用m$提供的asp.net管理工具管理一辈子么？

——当然不！那太可怕了！T_T

——我们要自己写一个后台，一个可以根据用户权限自己修改的后台！@_@

当然有一种数据库狂人，他们只冷冷的瞥了几眼m$提供的数据库结构，轻描淡写的破译了其中所有的奥妙之处，随手拖了5-6个grid 写了10多行SQL 就用数据库方式搞定了。对于这种高手，我们仰慕，我们恨不得马上吸光他的百年功力，然后杀之后快，NND.

但是成为这样的高手需要非常的经验和手腕。我们这些小菜鸟，没有写轮眼，也不是圣斗士，所谓“看穿”技能在我们的身上是不能工作的。我们只有membership标准对象 profile标准对象和roles标准对象。

难道就不能很方便的通过绑定方式访问这些对象么？

通过页面访问较为复杂的对象——在.net 1.x 的时代——对我们曾是一种煎熬。明明好多对象有着数据行的特性，为什么不能直接访问呢？于是好多人---包括我，尝试过各种办法。我是失败那批5555，也有很多的人成功了，研究出一些很有效的办法。可是这个状况没有持续多久——自从.net 2.0推出了ODS ，我的失败阴影就再也不复回来~~~

1 用ODS绑定MemberShip的总体思想

如图所示

从战略上我们把每个用户看成一个行，把Membership中的GetAllUsers ()看成一个Select语句。
但是一个标准的System.Web.Security.MembershipUser并不具有数据绑定对象的特性
比如主键/只读等信息所以我们可以重写它为它添加上这些特性

2 简单的绑定方法
这里采用的是MSDN上的部分c#代码修改成的VB代码顺便我也把版权信息粘贴上来

'/*

'Copyright ?2005, Peter Kellner

'http://peterkellner.net

'Redistribution and use in source and binary forms, with or without

'modification, are permitted provided that the following conditions

'are met:

'- Redistributions of source code must retain the above copyright

'notice, this list of conditions and the following disclaimer.

'- Neither Peter Kellner, nor the names of its

'contributors may be used to endorse or promote products

'derived from this software without specific prior written

'permission.

'THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

'"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

'LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

'FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

'COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

'INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES INCLUDING,

'BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

'LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

'CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

'LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

'ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

'POSSIBILITY OF SUCH DAMAGE.

'*/

Imports System

Imports System.Data

Imports System.Configuration

Imports System.Web

Imports System.Web.Security

Imports System.Web.UI

Imports System.Web.UI.WebControls

Imports System.Web.UI.WebControls.WebParts

Imports System.Web.UI.HtmlControls

Imports System.Collections.Generic

Imports System.ComponentModel

'/ <summary>

'/ Summary description for MembershipUserWrapper

'/ This class is inherited from MembershipUser

'/ Using the sytax public class ClassName (..) : base(initializers

) allows for calling the

'/ contstructor of the base class. In this case MembershipUser.

'/ </summary>

Namespace Membership_Tool

Public Class MembershipUserWrapper

Inherits MembershipUser

'/ <summary>

'/ This constructor is used to create a MembershipUserWrapper from a MembershipUser object. MembershipUser is a default type used

'/ in the Membership API provided with ASP.NET 2.0

'/ </summary>

'/ <param name="mu">MembershipUser object</param>

Public Sub New(ByVal mu As MembershipUser)

MyBase.New(mu.ProviderName, mu.UserName, mu.ProviderUserKey, mu.Email, mu.PasswordQuestion, mu.Comment, mu.IsApproved, mu.IsLockedOut, mu.CreationDate, mu.LastLoginDate, mu.LastActivityDate, mu.LastPasswordChangedDate, mu.LastLockoutDate)

End Sub 'New<DataObjectField(True)> _

'/ <summary>

'/ This calls the base class UserName property. It is here so we can tag

'/ this property as the primary key so that datakeynames attribute gets set in the data control.

'/ </summary>

<DataObjectField(True)> _

Public Overrides ReadOnly Property UserName() As String

Get

Return MyBase.UserName

End Get

End Property

'/ <summary>

'/ This constructor is used to create a MembershipUserWrapper from individual parameters values.

'/ For details of what each parameter means, see the Microsoft Membership class.

'/ </summary>

'/ <param name="comment">Passes to MembershipUser.comment</param>

'/ <param name="creationDate">Passes to MembershipUser.creationDate</param>

'/ <param name="email">Passes to MembershipUser.email</param>

'/ <param name="isApproved">Passes to MembershipUser.isApproved</param>

'/ <param name="lastActivityDate">Passes to MembershipUser.lastActivityDate</param>

'/ <param name="lastLoginDate">Passes to MembershipUser.lastLoginDate</param>

'/ <param name="passwordQuestion">Passes to MembershipUser.passwordQuestion</param>

'/ <param name="providerUserKey">Passes to MembershipUser.providerUserKey</param>

'/ <param name="userName">Passes to MembershipUser.userName</param>

'/ <param name="lastLockoutDate">Passes to MembershipUser.lastLockoutDate</param>

'/ <param name="providerName">Passes to MembershipUser.providerName</param>

Public Sub New(ByVal comment As String, ByVal creationDate As DateTime, ByVal email As String, ByVal isApproved As Boolean, ByVal lastActivityDate As DateTime, ByVal lastLoginDate As DateTime, ByVal passwordQuestion As String, ByVal providerUserKey As Object, ByVal userName As String, ByVal lastLockoutDate As DateTime, ByVal providerName As String)

MyBase.New(providerName, userName, providerUserKey, email, passwordQuestion, comment, isApproved, False, creationDate, lastLoginDate, lastActivityDate, DateTime.Now, lastLockoutDate)

End Sub 'New

End Class 'MembershipUserWrapper

' This calls a constructor of MembershipUser automatically because of the base reference above

End Namespace

这样MembershipUser 的Username 被标记成只读/主键在绑定的时候 GridView会识别这一说明生成相应的编辑模式模板。

数据行已经被我们建立好了，那么数据从哪里来呢？我们建立一个新类MembershipUserODS 把提供我们的数据的方法集中在这个类中，它就能起到Dataadepter的作用。

<DataObject(True)> _

Public Class MembershipUserODS

End Class

其中加入如下方法来实现数据的读取，也就是Select操作：

<DataObjectMethod(DataObjectMethodType.Select, False)> Public Shared _

Function GetMembers(ByVal returnAllApprovedUsers As Boolean, ByVal returnAllNotApprovedUsers As Boolean, ByVal usernameToFind As String) As List(Of MembershipUserWrapper)

Dim memberList As New List(Of MembershipUserWrapper)

'看看是否只需要返回某个特定的用户

If Not (usernameToFind Is Nothing) Then

' {

Dim mu As MembershipUser = Membership.GetUser(usernameToFind)

If Not mu Is Nothing Then

Dim md As MembershipUserWrapper = New MembershipUserWrapper(mu)

memberList.Add(md)

End If

Else

Dim muc As MembershipUserCollection = Membership.GetAllUsers()

Dim mu As MembershipUser

For Each mu In muc

If returnAllApprovedUsers = True And mu.IsApproved = True Or (returnAllNotApprovedUsers = True And mu.IsApproved = False) Then

Dim md As New MembershipUserWrapper(mu)

memberList.Add(md)

End If

Next mu

return memberList

end Function

（在随后的源代码包里面有排序的功能大家参考下就好）

这时候我们已经可以对 MembershipUserODS 进行数据绑定了----这个方法实现了数据绑定的最基础的动作：选择。

利用同样的方式我们建立对应插入、更新和删除操作的方法：
插入：

<DataObjectMethod(DataObjectMethodType.Insert, True)> Public Shared _

Sub Insert(ByVal userName As String, ByVal isApproved As Boolean, ByVal comment As String, ByVal lastLockoutDate As DateTime, ByVal creationDate As DateTime, ByVal email As String, ByVal lastActivityDate As DateTime, ByVal providerName As String, ByVal isLockedOut As Boolean, ByVal lastLoginDate As DateTime, ByVal isOnline As Boolean, ByVal passwordQuestion As String, ByVal lastPasswordChangedDate As DateTime, ByVal password As String, ByVal passwordAnswer As String)

' The incoming parameters, password and passwordAnswer are not properties of the

' MembershipUser class. Membership has special member functions to deal with these

' two special properties for security reasons. For this reason, they do not appear

' in a datacontrol that is created with this user object.

' the only reason you may want to have defaults is so you can build insert into your

' datacontrol. A better approach would be to either follow the example shown in the

' Membership.asp page where the parameters are set directly to the userobject, or not

' include "new" at all in your control and use the other controls in the Membership API

' for creating new members. (CreateUserWizard, etc)

' It is recommended that you only enable the following lines if you are sure of what you are doing

'if (password == null)

' password = "pass0word";

'if (passwordAnswer == null)

' passwordAnswer = "Password Answer";

Dim status As MembershipCreateStatus

Membership.CreateUser(userName, password, email, passwordQuestion, passwordAnswer, isApproved, status)

If status <> MembershipCreateStatus.Success Then

Throw New ApplicationException(status.ToString())

End If

Dim mu As MembershipUser = Membership.GetUser(userName)

mu.Comment = comment

Membership.UpdateUser(mu)

End Sub

更新：

<DataObjectMethod(DataObjectMethodType.Update, True)> Public Shared _

Sub Update(ByVal UserName As String, ByVal email As String, ByVal isApproved As Boolean, ByVal comment As String, ByVal lastActivityDate As DateTime, ByVal lastLoginDate As DateTime)

Dim dirtyFlag As Boolean = False

Dim mu As MembershipUser = Membership.GetUser(UserName)

If mu.Comment Is Nothing Or (mu.Comment & "").CompareTo(comment) <> 0 Then

dirtyFlag = True

mu.Comment = comment

End If

If mu.Email Is Nothing Or (mu.Email & "").CompareTo(email) <> 0 Then

dirtyFlag = True

mu.Email = email

End If

If mu.IsApproved <> isApproved Then

dirtyFlag = True

mu.IsApproved = isApproved

End If

If dirtyFlag = True Then

Membership.UpdateUser(mu)

End If

End Sub

删除：

<DataObjectMethod(DataObjectMethodType.Delete, True)> Public Shared _

Sub Delete(ByVal UserName As String)

Membership.DeleteUser(UserName, True)

End Sub

以上的工作，我们在ODS和membership之间建立了一条桥梁，通过我们的代码，membership 复杂的对象被我们用简单的数据属性所代理，而能够被ODS正确识别

下面我们简单的试验下我们工作的成果，亲手绑定一下。

建立一个新页面Default.aspx 在上面放置一个GridView和一个ODS控件。
效果如下图示：

选择“配置数据源”,你刚才建立的、带有<DataObject>声明的类便会被枚举出来：

下一步选择每种动作的对应方法：

当你把4种基本动作全部配置完毕，在属性栏把ObjectDataSource1.OldValuesParameterFormatString 的内容设置为{0} 就可以绑定了：

基本上不会出现什么错误拉。。。。

同样的方式你可以用如下的代码建立Roles和Profile 的绑定

Roles