按钮单击动态创建控件 [英] Create controls dynamically on button click

问题描述

I need to create dynamic controls on button click.  

HTML:

<asp:LinkButton ID="lnkSrt" runat="server" Text="Multi Sort" ForeColor="Black" Font-Names="Calibri" Font-Size="10pt" />
<ajax:ModalPopupExtender runat="server" ID="mpeSrt"
 TargetControlID="lnkSrt" PopupControlID="pnlSrt" CancelControlID="btnClose">
     </ajax:ModalPopupExtender>
         <asp:UpdatePanel ID="upPanel" runat="server">
             <ContentTemplate>
                  <asp:Panel ID="pnlSrt" runat="server" align="center" Style="display: none" BackColor="LightGray">
                  <asp:Label runat="server" Text="Sort By Column" />
                  <asp:DropDownList ID="ddlColumnSort" runat="server" AutoPostBack="true" />
                  <asp:Label runat="server" Text="Order By" />
                  <asp:DropDownList ID="ddlOrder" runat="server" AutoPostBack="true">
                  <asp:ListItem Text="Ascending" Value="0"></asp:ListItem>
                  <asp:ListItem Text="Descending" Value="1"></asp:ListItem>
                  </asp:DropDownList>
                  <asp:LinkButton ID="lnkAdd" runat="server" Text="Add Sorting" Font-Underline="true" OnClick="lnkAddOrder_Click" Font-Names="Calibri" Font-Size="10pt" ForeColor="Black" />
                  <asp:Button ID="btnSorting" runat="server" Text="Sort" OnClick="btnSorting_Click" />
                  <asp:Button ID="btnClose" runat="server" Text="Close" />
                </asp:Panel>
             </ContentTemplate>
          </asp:UpdatePanel>

我的尝试：

What I have tried:

CODE: 

When clicked on AddSorting I am trying to create dropdown control using below code and the controls doesn't show. 
 
protected void lnkAddSort_Click(object sender, EventArgs e)
{
int index = pnlSort.Controls.OfType<DropDownList>().ToList().Count + 1;
this.Createddl("ddldyn" + index);
}
public void Createddl(string id)
{
DropDownList ddl = new DropDownList();
ddl.ID = id;
pnlSort.Controls.Add(ddl);
Literal lt = new Literal();
lt.Text = "<br />";
pnlSort.Controls.Add(lt);
}

Can anyone please provide suggestions on how to handle this?

推荐答案

您是否尝试调试代码以查看它是否符合 OnClick 事件？查看您的代码，基于以下这一行：

Have you tried debugging your code to see if it hits the OnClick event? Looking at your code, based on this line:

<asp:LinkButton ID="lnkAdd" runat="server" Text="Add Sorting" Font-Underline="true" OnClick="lnkAddOrder_Click" Font-Names="Calibri" Font-Size="10pt" ForeColor="Black" />

你有线了 OnClick 事件到您的 LinkBut​​ton ，其名称为 lnkAddOrder_Click 但你的代码后面使用名称 lnkAddSort_Click 。您应该更改事件名称以匹配您在标记/ HTML中设置的事件处理程序。所以你应该有类似的东西：

You wired-up an OnClick event to your LinkButton which is named "lnkAddOrder_Click" but your code behind uses the name "lnkAddSort_Click". You should change the event name to match with the event handler you set in your markup/HTML. So you should have something like this instead:

protected void lnkAddOrder_Click(object sender, EventArgs e)
{
      //your code here
}

你也可以参考这个例子来讨论如何 [ ^ ]在ASP.NET WebForms中创建动态控件：

You can also refer this example on how to [^]create dynamic controls in ASP.NET WebForms:

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