RadioButtonList.Render(HtmlTextWriter) 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
在用戶端顯示 RadioButtonList 控制項。
protected:
override void Render(System::Web::UI::HtmlTextWriter ^ writer);protected public:
override void Render(System::Web::UI::HtmlTextWriter ^ writer);protected 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 -> unitProtected Overrides Sub Render (writer As HtmlTextWriter)Protected Friend Overrides Sub Render (writer As HtmlTextWriter)參數
- writer
- HtmlTextWriter
HtmlTextWriter，包含要在用戶端呈現的輸出資料流。
範例
下列程式碼範例示範如何在自訂伺服器控制項中覆寫 Render 方法， RadioButtonList 讓控制項一律以描述性文字顯示。
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<!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 RadioButtonList - Render - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom RadioButtonList - Render - C# Example</h3>
<aspSample:CustomRadioButtonListRender
id="Radiobuttonlist1"
runat="server"
RepeatColumns="2"
RepeatDirection="Horizontal">
<asp:ListItem Value="Item1">Item1</asp:ListItem>
<asp:ListItem Value="Item2">Item2</asp:ListItem>
<asp:ListItem Value="Item3">Item3</asp:ListItem>
<asp:ListItem Value="Item4">Item4</asp:ListItem>
</aspSample:CustomRadioButtonListRender>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<!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 RadioButtonList - Render - VB.NET Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom RadioButtonList - Render - VB.NET Example</h3>
<aspSample:CustomRadioButtonListRender
id="Radiobuttonlist1" runat="server"
RepeatColumns="2" RepeatDirection="Horizontal">
<asp:ListItem Value="Item1">Item1</asp:ListItem>
<asp:ListItem Value="Item2">Item2</asp:ListItem>
<asp:ListItem Value="Item3">Item3</asp:ListItem>
<asp:ListItem Value="Item4">Item4</asp:ListItem>
</aspSample:CustomRadioButtonListRender>
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomRadioButtonListRender : System.Web.UI.WebControls.RadioButtonList
{
protected override void Render(System.Web.UI.HtmlTextWriter writer)
{
// Call the base RenderContents method.
base.Render(writer);
// Append some text to the Image.
writer.Write("Experience Windows Server 2003 and Visual Studio® .NET 2003.");
}
}
}
Imports System.Web
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomRadioButtonListRender
Inherits System.Web.UI.WebControls.RadioButtonList
Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
' Call the base RenderContents method.
MyBase.Render(writer)
' Append some text to the Image.
writer.Write("Experience Windows Server 2003 and Visual Studio .NET 2003.")
End Sub
End Class
End Namespace
備註
這個方法主要是由衍生自 類別之 RadioButtonList 自訂控制項中的控制項開發人員使用。
Render控制項的方法實作 RadioButtonList 會初始化 RepeatInfo 清單的 物件，並呼叫 RenderRepeater 方法，接著會使用 RenderItem 方法來轉譯個別的選項按鈕清單專案。