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TextBox 构造函数

  • 参考

定义

命名空间:
System.Web.UI.WebControls
程序集:
System.Web.dll

初始化 TextBox 类的新实例。

public:
 TextBox();
public TextBox ();
Public Sub New ()

示例

下面的代码示例演示如何使用 TextBox 构造函数将控件动态添加到 TextBox 页面。

重要

此示例具有一个接受用户输入的文本框，这是一个潜在的安全威胁。 默认情况下，ASP.NET 网页验证用户输入是否不包含脚本或 HTML 元素。 有关详细信息，请参阅脚本侵入概述。

<%@ Page Language="C#" AutoEventWireup="True" %>

<!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>
    <title> TextBox Constructor Example </title>
<script runat="server">

      protected void Page_Load(Object sender, EventArgs e)
      {

         // Create UserTextBox TextBox control.
         TextBox UserTextBox = new TextBox();

         // Configure the UserTextBox TextBox control.
         UserTextBox.ID = "UserTextBox";
         UserTextBox.Columns = 50;


         // Add UserTextBox TextBox control to the Controls collection 
         // of the TextBoxControlPlaceHolder PlaceHolder control.
         TextBoxControlPlaceHolder.Controls.Add(UserTextBox);

      }

      protected void Submit_Click(Object sender, EventArgs e)
      {

         // Retrieve the UserTextBox TextBox control from the TextBoxControlPlaceHolder
         // PlaceHolder control.
         TextBox TempTextBox = (TextBox)TextBoxControlPlaceHolder.FindControl("UserTextBox");

         // Display the Text property.
         Message.Text = "The TextBox control above is dynamically generated. <br /> You entered: " + 
                        TempTextBox.Text;

      }

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> TextBox Constructor Example </h3>

      Enter some text and click the Submit button. <br /><br />

      <asp:PlaceHolder ID="TextBoxControlPlaceHolder"
           runat="server"/>

      <br /><br />
 
      <asp:Button ID="SubmitButton"
           Text="Submit"
           OnClick="Submit_Click"
           runat="server"/>

      <br /><br />

      <asp:Label ID="Message"
           runat="server"/>


   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>

<!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>
    <title> TextBox Constructor Example </title>
<script runat="server">

      Protected Sub Page_Load(sender As Object, e As EventArgs)

         ' Create UserTextBox TextBox control.
         Dim UserTextBox As New TextBox()

         ' Configure the UserTextBox TextBox control.
         UserTextBox.ID = "UserTextBox"
         UserTextBox.Columns = 50


         ' Add UserTextBox TextBox control to the Controls collection 
         ' of the TextBoxControlPlaceHolder PlaceHolder control.
         TextBoxControlPlaceHolder.Controls.Add(UserTextBox)

      End Sub

      Protected Sub Submit_Click(sender As Object, e As EventArgs)

         ' Retrieve the UserTextBox TextBox control from the TextBoxControlPlaceHolder
         ' PlaceHolder control.
         Dim TempTextBox As TextBox = CType(TextBoxControlPlaceHolder.FindControl("UserTextBox"), TextBox)

         ' Display the Text property.
         Message.Text = "The TextBox control above is dynamically generated. <br /> You entered: " & _ 
                        TempTextBox.Text

      End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> TextBox Constructor Example </h3>

      Enter some text and click the Submit button. <br /><br />

      <asp:PlaceHolder ID="TextBoxControlPlaceHolder"
           runat="server"/>

      <br /><br />
 
      <asp:Button ID="SubmitButton"
           Text="Submit"
           OnClick="Submit_Click"
           runat="server"/>

      <br /><br />

      <asp:Label ID="Message"
           runat="server"/>


   </form>

</body>
</html>

注解

使用此构造函数创建和初始化 类的新实例 TextBox 。

下表显示了 实例 TextBox的初始属性值。

properties 初始值
TagKey HtmlTextWriterTag.Input

适用于

另请参阅