動態產生表格及事件攔截 Part2
在之前 動態產生表格及事件攔截 的文章中，有示範如何「動態產生了 3 列 2 欄的表格及事件攔截」；本文將以這個範例延伸，當按一下按鈕就動態在表格中加入一筆新的資料列。
首先在頁面上放置一個 ID="btnAddRow" 的 Button，設定其屬性 UseSubmitBehavior="False" ，在 aspx 中的程式碼如下
<form id="form1" runat="server"> <div> <asp:Button ID="btnAddRow" runat="server" Text="Button" UseSubmitBehavior="False" /></div> </form>
在此範例中，利用了一個 HiddenField 來記錄 Table 的資料列數，並由 Request.Form("__EVENTTARGET") 判斷是否由 btnAddRow 按鈕產生的 PostBack。
*.aspx.vb
Partial Class _Default Inherits System.Web.UI.Page Private FRowCount As Integer 
Private FRowCountField As New HiddenField() 
Private ''' <summary> ''' 動態產生 Table。 ''' </summary> 
Private Sub CreateTable(ByVal RowCount As Integer) 
Private Dim oTable As New Table() Dim oRow As TableRow Dim oCell As TableCell Dim oButton As Button Dim oTextBox As TextBox Dim N1 As Integer Me.Form.Controls.Add(oTable) '建立3列1欄的，其中第1欄置放 Button，第2欄置放 TextBox For N1 = 1 To RowCount oRow = New TableRow() oTable.Rows.Add(oRow) oCell = New TableCell() oRow.Cells.Add(oCell) oButton = New Button oButton.Text = "Button" & N1.ToString() '將 Button 的 Click 事件導向 Button_Click 函式 AddHandler oButton.Click, AddressOf Button_Click oCell.Controls.Add(oButton) oCell = New TableCell() oRow.Cells.Add(oCell) oTextBox = New TextBox() oTextBox.Text = "TextBox" & N1.ToString() oCell.Controls.Add(oTextBox) Next 
End Sub Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init FRowCountField.ID = "__RowCount" Me.Form.Controls.Add(FRowCountField) '取得上次記錄的資料列數 If Me.Request.Form(FRowCountField.UniqueID) Is Nothing Then FRowCount = 0 Else FRowCount = CInt(Me.Request.Form(FRowCountField.UniqueID)) End If '由 Request.Form("__EVENTTARGET") 判斷是否由 btnAddRow 按鈕產生的 PostBack If Me.Request.Form("__EVENTTARGET") = btnAddRow.UniqueID Then FRowCount = FRowCount + 1 End If CreateTable(FRowCount) '動態產生 Table。 End Sub Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load FRowCountField.Value = FRowCount.ToString() End Sub 'Table 中所有的 Button 的 Click 事件導向函數 Protected Sub Button_Click(ByVal sender As Object, ByVal e As System.EventArgs) Dim oButton As Button Dim oRow As TableRow Dim oCell As TableCell Dim oTextBox As TextBox = Nothing oButton = CType(sender, Button) oCell = CType(oButton.Parent, TableCell) oRow = CType(oCell.Parent, TableRow) '取得內含 TextBox 的 Cell，即第2欄 oTextBox = CType(oRow.Cells(1).Controls(0), TextBox) oTextBox.Text = oButton.Text 
End Sub End Class