ASP 输入后更新文本框

Question

我在 asp 页面上有一个文本框。这个文本框充满了来自数据库的电子邮件，在文本框中每行打印一封电子邮件，每行由一个 vbCrLf 分隔以使其工作。文本框是可写的，因此人们可以输入更多电子邮件或删除该列表中的电子邮件。更改电子邮件列表后，有一个保存按钮，应在新的电子邮件列表中读取并将它们发回。

然而，在文本框中输入一封新电子邮件或从文本框中删除一封电子邮件后，我点击了保存按钮，在它后面的代码中，文本框的文本仍然读取为原始文本，没有任何变化。我不知道为什么，因为代码只在我进行更改后运行，所以当我调用 emailBox.Text（我的文本框）时，它应该查找文本框中的任何文本，对吗？任何和所有帮助将不胜感激。

这是我的代码：

VB:

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        Try
            emailBox.Text = ""
            Dim tempstoreID As Integer = 101
            Dim ds As DataSet
            Dim emailList As String = ""
            ds = DBUtility.GetKisokAlertEmails(tempstoreID)
            If Not ds Is Nothing AndAlso ds.Tables.Count > 0 And ds.Tables(0).Rows.Count > 0 Then
                For Each dr In ds.Tables(0).Rows
                    emailList = dr("EmailList")
                Next
            End If
            Dim seperatedEmailList() As String
            seperatedEmailList = Split(emailList, ";")
            For Each email As String In seperatedEmailList
                emailBox.Text &= email & vbCrLf
            Next

        Catch ex As Exception
            Dim tempstoreID As Integer = 101
            LogUtility.LogMessage("Error in getting and parsing email list from database. " & ex.ToString, LogUtility.INFO_MESSAGE, tempstoreID)
        End Try
    End Sub

Protected Sub SaveButton(sender As Object, e As EventArgs)
        Dim newEmailList() As String
        newEmailList = Split(emailBox.Text, vbCrLf)
        Dim regexExpression As New Regex("^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$")

        Dim valid As Boolean
        Dim errorEmail As String = "Nope"

        Dim counter As Integer = 0
        While counter < newEmailList.Length - 1
            If (regexExpression.IsMatch(newEmailList(counter))) Then
                valid = True
                counter += 1
            Else
                valid = False
                errorEmail = newEmailList(counter)
                Exit While
            End If

        End While

    End Sub

ASP:

<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:Label ID="label1" Text="List Of Emails" runat="server" /> <br />
            <asp:TextBox ID="emailBox" TextMode="MultiLine" Text="" AutoPostBack="true" runat="server" />
            <br/><br/>
            <asp:Button Text="Save" OnClick="SaveButton" runat="server" />
            <asp:Button Text="Cancel" runat="server" />
            <br />
            <asp:Label ID="TestLabel" Text = "Hi" runat="server"/>
            <br />
            <asp:Label ID="TestLabel2" Text ="howdy" runat="server" />
            <br />
            <asp:Label ID="TestLabel3" Text = "emails" runat="server" />
        </div>
    </form>
</body>
</html>

Answer 1

当您单击 button 保存时，Form1_Load 首先执行，然后在您的 SaveButton 函数之后执行，这就是您拥有旧数据的原因。所以你需要把你的 Form1_Load 代码放在 PostBack 中：

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

   if not IsPostBack then
       //your code
   end if

End Sub

您可以检查 this post 关于回发。

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