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 -> unit
Protected 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。
適用於
另請參閱
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