如何使用ASP.NET获取所选动态单选按钮VB.NET的ID [英] How do I get the ID of the selected dynamic radiobutton VB.NET with ASP.NET
问题描述
我已经动态生成了radiobuttons，当我点击所选按钮时，如果文本框（textbox2）中的动态单选按钮，我如何获得id。
下面的代码仅用于生成控件（收音机和文本框），我的意思是btnload工作，但btnselected不起作用（动态控件只是消失，textbox2显示没有。）。
I have dynamically generated radiobuttons, How can I get the id if the dynamic radiobuttons in a textbox (textbox2) when I cick on the selected button.
the code below only works for generating the controls (radio and textboxes), I mean the btnload works but the btnselected does not work (the dynamic controls just vanish and textbox2 dispalys nothing.).
<html>
<head id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<asp:Panel ID="container" runat="server">
</asp:Panel>
<div>
<asp:Button ID="btnload" runat="server" Text="Load" />
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
no of loops</div>
<asp:Button ID="btnselected" runat="server" Text="selected" />
<asp:TextBox ID="TextBox2" runat="server" style="margin-top: 26px"></asp:TextBox>
</form>
</body>
</html>
Protected Sub getradioId_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnload.Click
Dim tbl As New Table
tbl.Width = 500
Dim i As Integer = 0
Do Until i = TextBox1.Text
Dim tblrow As New TableRow
tblrow.Width = 80%
Dim tblcellrad As New TableCell
tblcellrad.Width = 100
Dim tblcellname As New TableCell
tblcellname.Width = 300
Dim cand As New TextBox
cand.ID = i
i += 1
Dim rad As New RadioButton 'generate controls (radiobuttons and textbox)
rad.GroupName = "one"
rad.ID = i
rad.Text = "rad" & i
cand.Text = "candidate " & i.ToString
If i Mod 2 = 1 Then 'set row colour
tblrow.Style.Add("background-color", "#EEEEEE")
Else
tblrow.Style.Add("background-color", "#E0E0E0")
End If
tblcellrad.Controls.Add(rad) 'add controls to cells
tblcellname.Controls.Add(cand)
tblrow.Controls.Add(tblcellname) 'add cells to rows
tblrow.Controls.Add(tblcellrad)
tbl.Controls.Add(tblrow) 'add row to table
container.Controls.Add(tbl)
Loop
End Sub
Protected Sub btnselected_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnselected.Click
Dim radios = Controls.OfType(Of RadioButton).AsQueryable()
For Each r As RadioButton In radios
If r.Checked Then
TextBox2.Text = r.ID.ToString
End If
Next
End Sub
推荐答案
参考 - 保留ASP.NET应用程序中动态创建的控件的状态 [ ^ ]。
Refer - Retaining State for Dynamically Created Controls in ASP.NET applications[^].
在运行时动态地向ASP.NET页面添加控件时，对象引用会在回发时丢失，因为它们在代码隐藏中没有句柄。在回发后访问这些对象时，用户输入的值不可用，并且它们看起来是空的。本文介绍如何使用ViewState重新创建并将回发值重新插入到对象中以访问其值。
When dynamically adding controls to an ASP.NET page in runtime the object references are lost at postback because they have no handle in the codebehind. The values entered by the user is not availible when accessing these objects after postback, and they seem empty. This article describes how to use ViewState to recreate and reinsert the postback values into the objects to access their values.
您必须在每个Post Post中重新创建控件。
You have to recreate the controls in each Post Back.
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