Question

我在usercontrol中有两个ASP.NET ListBoxex。数据绑定事件触发一次。我确定，我确实跟踪。但是listbox总是返回第一个值！这对我来说很奇怪。我不知道如何解决它。感谢帮助。这是用户控制源：

<asp:UpdatePanel ID="updPanel" runat="server" ChildrenAsTriggers="true">
<ContentTemplate>
    <table class="style1">
        <tr>
            <td align="left" dir="rtl" valign="top" width="250">
                <asp:ListBox ID="lst2" runat="server" DataTextField="Title" 
                    DataValueField="Value" Font-Names="Tahoma" Font-Size="Small" Height="306px" 
                    Width="230px"></asp:ListBox>
            </td>
            <td align="right" dir="rtl" width="30">
                <table>
                    <tr>
                        <td width="25">
                            <asp:Button ID="btnAdd" runat="server" meta:resourcekey="btnAddResource1" 
                                Text="&gt;" Width="28px" />
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <asp:Button ID="btnAddAll" runat="server" meta:resourcekey="btnAddAllResource1" 
                                Text="&gt;&gt;" Width="28px" />
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <asp:Button ID="btnRemove" runat="server" meta:resourcekey="btnRemoveResource1" 
                                Text="&lt;" Width="28px" />
                        </td>
                    </tr>
                    <tr>
                        <td>
                            <asp:Button ID="btnRemoveAll" runat="server" 
                                meta:resourcekey="btnRemoveAllResource1" Text="&lt;&lt;" Width="28px" />
                        </td>
                    </tr>
                </table>
            </td>
            <td align="left" valign="top" width="250">
                <asp:ListBox ID="lst1" runat="server" DataTextField="Title" 
                    DataValueField="value" Font-Names="Tahoma" Font-Size="Small" Height="306px" 
                    Width="230px"></asp:ListBox>
            </td>
        </tr>
    </table>
</ContentTemplate>

这是我背后的代码

   Public Property UserName As String
    Get
        Return ViewState("UserName")
    End Get
    Set(ByVal value As String)
        ViewState("UserName") = value

    End Set
End Property
Protected Sub btnAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAdd.Click
    MsgBox(lst2.SelectedItem.Text)
End Sub

Public Sub BindUserNotInGroups()
    Dim objSecurity As New Negso.Security.SecurityHelper()
    Dim dt As New DataTable
    dt = objSecurity.GetNonGroupsForUser(UserName)
    lst2.DataValueField = dt.Columns("SID").ColumnName
    lst2.DataTextField = dt.Columns("Name").ColumnName
    lst2.DataSource = dt
    lst2.DataBind()
End Sub
''' <summary>
''' Binds the user not in groups.
''' </summary>
''' <remarks></remarks>
Public Sub BindUserInGroups()

    Dim objSecurity As New Negso.Security.SecurityHelper()
    'Dim k = objSecurity.GetGroupsForUser(UserName).Rows.Count
    Dim dt As New DataTable
    dt = objSecurity.GetGroupsForUser(UserName)
    lst1.DataValueField = dt.Columns("SID").ColumnName
    lst1.DataTextField = dt.Columns("Name").ColumnName
    lst1.DataSource = dt
    lst1.DataBind()
End Sub

我将在设置Username属性时调用绑定函数：

Public Property UserName() As String
    Get
        Return ViewState("UserName")
    End Get
    Set(ByVal value As String)

        ViewState("UserName") = value
        userGroups1.UserName = ViewState("UserName")
        userGroups1.BindUserInGroups()
        userGroups1.BindUserNotInGroups()
        'ListBox3.UserName = ViewState("UserName")
    End Set

Answer 1

基本上这不是最好的方法。你应该像这样工作

public overrides sub onload()

if (not String.isNullOrEmpty(UserName) and not Page.IsPostBack) OR Me.UserNameChanged then

        userGroups1.UserName = Me.UserName
        userGroups1.BindUserInGroups()
        userGroups1.BindUserNotInGroups()


end if

end sub

好的，像这样

Public Class testpage
    Inherits System.Web.UI.Page

    Private lst2 As New ListBox
    Private WithEvents btnadd As New Button


    Private _UserNameChanged As Boolean
    Public Property UserNameChanged() As Boolean
        Get
            Return _UserNameChanged
        End Get
        Set(ByVal value As Boolean)
            _UserNameChanged = value
        End Set
    End Property

    Public Property UserName As String
        Get
            Return ViewState("UserName")
        End Get
        Set(ByVal value As String)
            If ViewState("UserName") <> value Then
                UserNameChanged = True
            End If
            ViewState("UserName") = value
        End Set
    End Property

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        If Not Me.Page.IsPostBack And Not String.IsNullOrEmpty(UserName) Then
            Me.DataBind(True)
        End If

    End Sub

    Private Sub onbtnClick() Handles btnadd.Click

        If Me.UserNameChanged And Not String.IsNullOrEmpty(UserName) Then
            Me.DataBind(True)
        End If

    End Sub

    Public Overrides Sub DataBind()

        userGroups1.UserName = Me.UserName
        userGroups1.BindUserInGroups()
        userGroups1.BindUserNotInGroups()

        MyBase.DataBind()
    End Sub

End Class

ASP.NET ListBox始终返回第一个值（-1选定索引）

1 个答案: