Question

如何从代码后面的字符串中在网页上呈现asp.net控件？

例如，假设我有下面的aspx页面：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="nrm.FRGPproposal.Questionnaire1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        //want to render a text box here
    </div>
    </form>
</body>
</html>

我可以在我的Page_Load事件中将TextBox渲染到div中吗？

protected void Page_Load(object sender, EventArgs e)
{
    //what do i do here to render a TextBox in the div from the aspx page?
}

Answer 1

注意这里可能存在编译问题。但基本上是将占位符控件添加到前面的代码中＆lt;％@ Page Language =“C＃”AutoEventWireup =“true”CodeBehind =“Default.aspx.cs”Inherits =“nrm.FRGPproposal.Questionnaire1”％＆gt;

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:placeholder id="placeHolder" runat="server"/>
    </div>
    </form>
</body>
</html>

然后以编程方式在代码中创建一个TextBox。您需要包含System.Web.UI才能获取文本框。然后将控件添加到placeHolder上的控件集合中。以编程方式在文本框中设置您喜欢的任何属性

protected void Page_Load(object sender, EventArgs e)
{
    TextBox tb = new TextBox();
    placeHolder.Controls.Add(tb); //tb is referring to the name that you want to name your element. in this example given was TextBox. so the name of text box is tb. 

}

Answer 2

您还需要在Page_Init方法中重建控件，以便在PostBack上读取控件的状态/值。

protected void Page_Init(object sender, System.EventArgs e)
{
    TextBox tb = new TextBox();
    placeHolder.Controls.Add();
}

如何动态呈现控件？

2 个答案: