TextBox.Render(HtmlTextWriter) TextBox.Render(HtmlTextWriter) TextBox.Render(HtmlTextWriter) TextBox.Render(HtmlTextWriter) Method

定義

TextBox 控制項呈現為指定的 HtmlTextWriter 物件。Renders the TextBox control to the specified HtmlTextWriter object.

protected public:
 override void Render(System::Web::UI::HtmlTextWriter ^ writer);
protected internal override void Render (System.Web.UI.HtmlTextWriter writer);
override this.Render : System.Web.UI.HtmlTextWriter -> unit
Protected Friend Overrides Sub Render (writer As HtmlTextWriter)

參數

writer
HtmlTextWriter HtmlTextWriter HtmlTextWriter HtmlTextWriter

接收所呈現之輸出的 HtmlTextWriterThe HtmlTextWriter that receives the rendered output.

範例

下列程式碼範例示範如何覆寫自Render定義伺服器控制項中的方法,讓TextBox控制項一律以影像顯示。The following code example demonstrates how to override the Render method in a custom server control so that the TextBox control is always displayed with an image.

重要

這個範例有一個可接受使用者輸入的文字方塊,這可能會造成安全性威脅。This example has a text box that accepts user input, which is a potential security threat. 根據預設,ASP.NET Web 網頁會驗證使用者輸入未包含指令碼或 HTML 項目。By default, ASP.NET Web pages validate that user input does not include script or HTML elements. 如需詳細資訊,請參閱 Script Exploits Overview (指令碼攻擊概觀)。For more information, see Script Exploits Overview.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ 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>Custom TextBox - Render - C# Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom TextBox - Render - C# Example</h3>
            
            <aspSample:CustomTextBoxRender 
              id="TextBox1" 
              runat="server">Hello World!
            </aspSample:CustomTextBoxRender>
            
        </form>
    </body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ 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>Custom TextBox - Render - VB.NET Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom TextBox - Render - VB.NET Example</h3>
            
            <aspSample:CustomTextBoxRender id="TextBox1" 
             runat="server">Hello World!</aspSample:CustomTextBoxRender>
        </form>
    </body>
</html>
using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomTextBoxRender : System.Web.UI.WebControls.TextBox
  {
    protected override void Render(System.Web.UI.HtmlTextWriter writer)
    {
      // Create and render a new Image Web control.
      System.Web.UI.WebControls.Image image = new System.Web.UI.WebControls.Image();
      image.ID = "Image1";
      image.ImageUrl = "image.jpg";	
      image.AlternateText = "Image for TextBox1.";
      image.RenderControl(writer);

      // Create a BR tag.
      writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Br);

      // Call the base class's Render method.
      base.Render(writer);
    }
  }
}
Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomTextBoxRender
        Inherits System.Web.UI.WebControls.TextBox

        Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)

            ' Create and render a new Image Web control.
            Dim image As New System.Web.UI.WebControls.Image
            image.ID = "Image1"
            image.ImageUrl = "image.jpg"
            image.AlternateText = "Image for TextBox1."
            image.RenderControl(writer)

            ' Create a BR tag.
            writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Br)

            ' Call the base class's Render method.
            MyBase.Render(writer)
        End Sub
    End Class
End Namespace

備註

方法會將TextBox控制項的開始標記和結束標記呈現給HtmlTextWriter用戶端上的輸出物件。 RenderThe Render method renders the begin tag and end tag of the TextBox control to the HtmlTextWriter object for output on the client. 如果屬性設定為MultiLine <textarea> ,則會將控制項的內容轉譯為HTML元素。TextBox TextModeIf the TextMode property is set to MultiLine, the content of the TextBox control is rendered as an HTML <textarea> element.

方法主要由控制項開發人員擴充TextBox控制項的功能所使用。 RenderThe Render method is used primarily by control developers extending the functionality of the TextBox control.

適用於

另請參閱