Question

我的代码隐藏（c＃）文件使用while（）循环为我数据库中任何给定数量的问题动态声明RadioButtonLists：

我在for循环中为每个tmpRBL添加项目。

我将每个RadioButtonList注册到我在while（）循环的每次迭代开始时创建的子面板。

然后我将每个面板添加到父面板。

while(reader.Read()
{ 
    ...

    RadioButtonList tmpRBL = new RadioButtonList();
    temp = "RadioButtonList" + count.ToString();
    tmpRBL.ID = temp;
    tmpRBL.RepeatDirection = System.Web.UI.WebControls.RepeatDirection.Vertical;
    tmpRBL.TextAlign = System.Web.UI.WebControls.TextAlign.Left;

    ...

    for (int i = 1; i <= numAnswers; i++)
    {
        tmpItem = new ListItem("", i.ToString());
        tmpRBL.Items.Add(tmpItem);
    }

    ...

    p.Controls.Add(tmpRBL);

    ...

    questionPanel.Controls.Add(p);

}

如何检索这些动态创建的RadioButtonLists的selectedIndex？我花了大部分时间在线尝试其他类似问题的各种修复，但没有运气。

如果我在Chrome中使用'Inspect Element'，我可以在他们想要的位置看到RadioButtonLists，表面上是我分配的ID（RadioButtonList1，RadioButtonList2等），但我尝试的所有内容都以null对象结束。

我对C＃比较陌生，这是我第一次处理动态控件，所以提前感谢所提供的任何帮助。

Answer 1

基本上，如果您动态创建控件，则需要在页面的每个帖子中重新加载这些控件（ 具有相同的ID ）。

否则，它们将变为null，您将无法访问它们。

这是一个示例。它会动态加载RadioButtonList控件，并在单击按钮时显示所选的值。

<asp:PlaceHolder runat="server" ID="PlaceHolder1"/>
<asp:Button runat="server" ID="Button1" OnClick="Button1_Click" Text="Submit" />
<asp:Label runat="server" ID="Label1"/>

protected void Page_Load(object sender, EventArgs e)
{
    LoadControls();
}

protected void Button1_Click(object sender, EventArgs e)
{
    var radioButtonList = PlaceHolder1.FindControl("1") as RadioButtonList;
    Label1.Text = radioButtonList.SelectedValue;
}

private void LoadControls()
{
    var tmpRBL = new RadioButtonList();
    tmpRBL.ID = "1";

    for (int i = 1; i <= 5; i++)
    {
        var tmpItem = new ListItem(i.ToString(), i.ToString());
        tmpRBL.Items.Add(tmpItem);
    }

    PlaceHolder1.Controls.Add(tmpRBL);
}

Answer 2

非常感谢。以同样的方式，我，finnaly设法控制其他控件:-)。这是vb.net中的代码隐藏。

我现在非常幸运： - ）

创造＆amp;从动态创建的RadioButtonList＆amp;中检索值。文本框

Private Property RadioButtonList As RadioButtonList
    Private Property TextBoxList As TextBox


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

        LoadControls()

    End Sub           



    Protected Sub Button111_Click(sender As Object, e As EventArgs)
        Dim majstor_rbl(3) As String
        Dim majstor_txt(3) As String

        For i As Integer = 1 To 3
            RadioButtonList = TryCast(PlaceHolder1.FindControl(i & "rbl"), RadioButtonList)
            majstor_rbl(i) = RadioButtonList.SelectedValue
            TextBoxList = TryCast(PlaceHolder1.FindControl(i & "txt"), TextBox)
            majstor_txt(i) = TextBoxList.Text
        Next

        txt_podatak4.Text = majstor_rbl(1) & " - " & majstor_txt(1)
        txt_podatak5.Text = majstor_rbl(2) & " - " & majstor_txt(2)
        txt_podatak6.Text = majstor_rbl(3) & " - " & majstor_txt(3)
    End Sub

    Private Sub LoadControls()
        For j As Integer = 1 To 3

            Dim tmpRBL As Object = New RadioButtonList
            Dim tmpTXT As Object = New TextBox

            tmpRBL.ID = j & "rbl"
            tmpTXT.ID = j & "txt"



            For i As Integer = 1 To 3
                Dim tmpItem As Object = New ListItem("&nbsp;&nbsp;&nbsp;", i.ToString())
                tmpRBL.Items.Add(tmpItem)
            Next


            tmpRBL.RepeatLayout = RepeatLayout.Flow
            tmpRBL.RepeatDirection = RepeatDirection.Horizontal


            PlaceHolder1.Controls.Add(tmpTXT)
            PlaceHolder1.Controls.Add(tmpRBL)
            PlaceHolder1.Controls.Add(New LiteralControl("</br>"))
        Next

    End Sub

.aspx

    <asp:PlaceHolder runat="server" ID="PlaceHolder1"/>
    <asp:Button runat="server" ID="Button3" OnClick="Button111_Click" Text="Submit" />
<asp:TextBox ID="txt_podatak4" runat="server" CssClass="form-control"></asp:TextBox>
<asp:TextBox ID="txt_podatak5" runat="server" CssClass="form-control"></asp:TextBox>
<asp:TextBox ID="txt_podatak6" runat="server" CssClass="form-control"></asp:TextBox>

从动态创建的RadioButtonList中检索值

2 个答案: