AttributeCollection.Render(HtmlTextWriter) 方法

  • 參考

定義

命名空間:
System.Web.UI
組件:
System.Web.dll

將屬性集合寫入為集合所屬控制項所指定的 HtmlTextWriter 輸出資料流。

public:
 void Render(System::Web::UI::HtmlTextWriter ^ writer);
public void Render (System.Web.UI.HtmlTextWriter writer);
member this.Render : System.Web.UI.HtmlTextWriter -> unit
Public Sub Render (writer As HtmlTextWriter)

參數

writer
HtmlTextWriter

HtmlTextWriter 執行個體，會將屬性集合寫入目前的輸出資料流。

範例

本節包含兩個程式碼範例。 第一個程式碼範例示範如何繼承自 類別， WebControl 以建立名為 AttribRender 的自訂控制項，以覆寫 Render 方法。 第二個程式碼範例示範如何在 ASP.NET 網頁中使用自訂控制項。

下列範例示範如何建立名為 AttribRender 的自訂控制項，以覆寫 Render 類別的 WebControl 方法，而不呼叫 Render 基類的 方法。 AttribRender而是叫用 Render 方法。

/* Create a custom WebControl class, named AttribRender, that overrides
   the Render method to write two introductory strings. Then call the
   AttributeCollection.Render method, which allows the control to write the
   attribute values that are added to it when it is included in a page.
*/

using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Permissions;

// Create the namespace that contains the AttribRender and the
// page that accesses it.
namespace AC_Render
{
   // This is the custom WebControl class.
   [AspNetHostingPermission(SecurityAction.Demand,
      Level=AspNetHostingPermissionLevel.Minimal)]
   public class AttribRender : WebControl
   {
      // This is the overridden WebControl.Render method.
      protected override void Render(HtmlTextWriter output)
      {
         output.Write("<h2>An AttributeCollection.Render Method Example</h2>");
         output.Write("The attributes, and their values, added to the ctl1 control are <br><br>");
         // This is the AttributeCollection.Render method call. When the
         // page that contains this control is requested, the
         // attributes that the page adds, and their values,
         // are rendered to the page.
         Attributes.Render(output);
      }
   }
}

' Create a custom WebControl class, named AttribRender, that overrides 
' the Render method to write two introductory strings. Then call the
' AttributeCollection.Render method, which allows the control to write the
' attribute values that are added to it when it is included in a page.
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Security.Permissions

' Create the namespace that contains the AttribRender and the
' page that accesses it.
Namespace AC_Render

 ' This is the custom WebControl class.
    <AspNetHostingPermission(SecurityAction.Demand, _
      Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public Class AttribRender
        Inherits WebControl

        ' This is the overridden WebControl.Render method.
        Protected Overrides Sub Render(ByVal output As HtmlTextWriter)
            output.Write("<h2>An AttributeCollection.Render Method Example</h2>")
            output.Write("The attributes, and their values, added to the ctl1 control are <br><br>")
            ' This is the AttributeCollection.Render method call. When the
            ' page that contains this control is requested, the
            ' attributes that the page adds, and their values,
            ' are rendered to the page.
            Attributes.Render(output)
        End Sub
    End Class

End Namespace 'AC_Render

下列範例示範如何在網頁中使用 AttribRender 自訂控制項。 它假設自訂控制項的程式碼檔案位於應用程式的 App_Code 資料夾中。

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

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

<script runat="server">

  protected void Page_Load(object sender, EventArgs e)
  {
    AC_Render.AttribRender c = new AC_Render.AttribRender();
    c.Attributes.Add("Text", "Hello World!");
    c.Attributes.Add("Attribute1", "The value for Attribute1.");
    Place1.Controls.Add(c);
    
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>AttributeCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <asp:PlaceHolder id="Place1" runat="server"></asp:PlaceHolder>
    </div>
    </form>
</body>
</html>

<%@ Page Language="VB"%>

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

<script runat="server">

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

    Dim c As New AC_Render.AttribRender()
    c.Attributes.Add("Text", "Hello World!")
    c.Attributes.Add("Attribute1", "The value for Attribute1.")
    Place1.Controls.Add(c)

  End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>AttributeCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <asp:PlaceHolder id="Place1" runat="server"></asp:PlaceHolder>
    </div>
    </form>
</body>
</html>

適用於

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