CheckBoxList.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。
在用戶端上顯示 CheckBoxList。
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，以便一 CheckBoxList 律顯示影像。
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page language="c#" %>
<!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 CheckBoxList - Render - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom CheckBoxList - Render - C# Example</h3>
<aspSample:CustomCheckBoxListRender
id="CheckBoxList1" runat="server">
<asp:ListItem Selected="True">Item 1</asp:ListItem>
<asp:ListItem>Item 2</asp:ListItem>
<asp:ListItem>Item 3</asp:ListItem>
<asp:ListItem>Item 4</asp:ListItem>
<asp:ListItem>Item 5</asp:ListItem>
<asp:ListItem>Item 6</asp:ListItem>
</aspSample:CustomCheckBoxListRender>
</form>
</body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page language="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 CheckBoxList - Render - VB.NET Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom CheckBoxList - Render - VB.NET Example</h3>
<aspSample:CustomCheckBoxListRender id="CheckBoxList" runat="server"
RepeatLayout="Table" RepeatColumns="2" CellSpacing="3" CellPadding="3">
<asp:ListItem Selected="True">Item 1</asp:ListItem>
<asp:ListItem>Item 2</asp:ListItem>
<asp:ListItem>Item 3</asp:ListItem>
<asp:ListItem>Item 4</asp:ListItem>
<asp:ListItem>Item 5</asp:ListItem>
<asp:ListItem>Item 6</asp:ListItem>
</aspSample:CustomCheckBoxListRender>
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomCheckBoxListRender : System.Web.UI.WebControls.CheckBoxList
{
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 CheckBoxList1.";
image.RenderControl(writer);
// 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 CustomCheckBoxListRender
Inherits System.Web.UI.WebControls.CheckBoxList
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 CheckBoxList1."
image.RenderControl(writer)
' Call the base class's Render method.
MyBase.Render(writer)
End Sub
End Class
End Namespace
備註
方法 Render 主要是由衍生自 類別的 CheckBoxList 自訂控制項中的控制項開發人員使用。
Render控制項的實作 CheckBoxList 會初始化 RepeatInfo 清單的物件，並呼叫 RenderRepeater 方法，接著會使用 RenderItem 方法來轉譯個別核取方塊清單專案。
