创建webpart 简单实例
通常有两种方法可以创建webpart,一种是在Web Part Zone采用用户控件，另一种通过 WebPart class基类创建。Web Part Framework 可以自动处理这两种方式。
下面是一个如何用这两种方法生成标准的Web Part。
Listing 1. HelloWorldPart.ascx
<%@ Control Language="VB" ClassName="HelloWorldPart" %>
Hello World!
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Listing 2. App_Code\HelloWorldPart.vb
Imports System
Imports System.Web.UI
Imports System.Web.UI.WebControls.WebParts
Namespace myControls
''' <summary>
''' True Web Part
''' </summary>
Public Class HelloWorldPart
Inherits WebPart
Protected Overrides Sub RenderContents(ByVal writer As HtmlTextWriter)
writer.Write("Hello World!")
End Sub
End Class
End Namespace
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注意：要创建App_code子目录，以便.net自动编译。
Listing 3. ShowHelloWorldPart.aspx
<%@ Page Language="VB" %>
<%@ Register TagPrefix="custom" Namespace="myControls" %>
<%@ Register TagPrefix="user" TagName="HelloWorldPart" Src="~/HelloWorldPart.ascx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<style type="text/css">
.column
{
float:left;
width:45%;
height:200px;
margin-right:10px;
border:solid 1px black;
background-color: white;
}
html
{
background-color:#eeeeee;
}
</style>
<title>Show Hello World Part</title>
</head>
<body>
<form id="form1" runat="server">
<asp:WebPartManager
id="WebPartManager1"
Runat="server" />
<asp:WebPartZone
id="WebPartZone1"
CssClass="column"
Runat="server">
<ZoneTemplate>
<user:HelloWorldPart
id="HelloWorldPart1"
Runat="server" />
</ZoneTemplate>
</asp:WebPartZone>
<asp:WebPartZone
id="WebPartZone2"
CssClass="column"
Runat="server">
<ZoneTemplate>
<custom:HelloWorldPart
id="HelloWorldPart2"
Runat="server" />
</ZoneTemplate>
</asp:WebPartZone>
</form>
</body>
</html>
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注意：要想看见Web Part Zones的菜单选项，请先用asp.net 2.0 的login注册。
标准的 Web Part 属性包括：
-
AuthorizationFilter ：让Web Part Manager 检查使用Web Parts的权限。
-
CatalogIconImageUrl ：显示在Catalog Part的图标
-
Description
-
ExportMode ：在Web Part 下载 XML文件 。分成 All, None, and NonSensitiveData三种方式。
-
Height
-
Subtitle ：在标题后面再附加子标题
-
Title
-
TitleIconImageUrl
-
TitleUrl
-
Width
如：
<user:HelloWorldPart id="HelloWorldPart1" Title="Hello World" Description="Displays Hello World" Runat="server" />
下面我们用这两种方式分别演示如何确定这些属性。
Listing 5. RandomQuotePart.ascx
<%@ Control Language="VB" ClassName="RandomQuotePart" %>
<%@ Implements Interface="System.Web.UI.WebControls.WebParts.IWebPart" %>
<%@ Import Namespace="System.Collections.Generic" %>
<script runat="server">
Private _title As String = "Random Quote"
Private _titleUrl As String = "~/Help.aspx"
Private _description As String = "Displays a random quote"
Private _subTitle As String = "User Control Version"
Private _catalogIconImageUrl As String = "~/Images/BigRandomQuote.gif"
Private _titleIconImageUrl As String = "~/Images/SmallRandomQuote.gif"
Public Property Title() As String Implements IWebPart.Title
Get
Return _title
End Get
Set(ByVal Value As String)
_title = Value
End Set
End Property
Public Property TitleUrl() As String Implements IWebPart.TitleUrl
Get
Return _titleUrl
End Get
Set(ByVal Value As String)
_titleUrl = Value
End Set
End Property
Public Property Description() As String Implements IWebPart.Description
Get
Return _description
End Get
Set(ByVal Value As String)
_description = Value
End Set
End Property
Public ReadOnly Property Subtitle() As String Implements IWebPart.Subtitle
Get
Return _subTitle
End Get
End Property
Public Property CatalogIconImageUrl() As String Implements IWebPart.CatalogIconImageUrl
Get
Return _catalogIconImageUrl
End Get
Set(ByVal Value As String)
_catalogIconImageUrl = Value
End Set
End Property
Public Property TitleIconImageUrl() As String Implements IWebPart.TitleIconImageUrl
Get
Return _titleIconImageUrl
End Get
Set(ByVal Value As String)
_titleIconImageUrl = Value
End Set
End Property
Private Sub Page_PreRender()
Dim quotes As New List(Of String)
quotes.Add("All paid jobs absorb and degrade the mind -- Aristotle")
quotes.Add("No evil can happen to a good man, either in life or after death -- Plato")
quotes.Add("The only good is knowledge and the only evil is ignorance -- Plato")
Dim rnd As New Random()
lblQuote.Text = quotes(rnd.Next(quotes.Count))
End Sub
</script>
<asp:Label
id="lblQuote"
runat="server" />
注意： <%@ Implements %>为User control i提供了 IWebPart 接口. 提供了标准属性的Default values 。 |
由于Web Part control 来自Web Part基类，必然包含IWebPart接口的所有属性。我们只需覆盖。
Listing 6. App_Code\RandomQuotePart.vb
Imports System
Imports System.Collections.Generic
Imports System.Web.UI
Imports System.Web.UI.WebControls.WebParts
Namespace myControls
''' <summary>
''' Displays a random quotation
''' </summary>
Public Class RandomQuotePart
Inherits WebPart
Private _title As String = "Random Quote"
Private _titleUrl As String = "~/Help.aspx"
Private _description As String = "Displays a random quote"
Private _subTitle As String = "True Web Part Version"
Private _catalogIconImageUrl As String = "~/Images/BigRandomQuote.gif"
Private _titleIconImageUrl As String = "~/Images/SmallRandomQuote.gif"
Public Overrides Property Title() As String
Get
Return _title
End Get
Set(ByVal Value As String)
_title = value
End Set
End Property
Public Overrides Property TitleUrl() As String
Get
Return _titleUrl
End Get
Set(ByVal Value As String)
_titleUrl = value
End Set
End Property
Public Overrides Property Description() As String
Get
Return _description
End Get
Set(ByVal Value As String)
_description = value
End Set
End Property
Public Overrides ReadOnly Property Subtitle() As String
Get
Return _subTitle
End Get
End Property
Public Overrides Property CatalogIconImageUrl() As String
Get
Return _catalogIconImageUrl
End Get
Set(ByVal Value As String)
_catalogIconImageUrl = value
End Set
End Property
Public Overrides Property TitleIconImageUrl() As String
Get
Return _titleIconImageUrl
End Get
Set(ByVal Value As String)
_titleIconImageUrl = value
End Set
End Property
Protected Overrides Sub RenderContents(ByVal writer As HtmlTextWriter)
Dim quotes As New List(Of String)()
quotes.Add("All paid jobs absorb and degrade the mind -- Aristotle")
quotes.Add("No evil can happen to a good man, either in life or after death --
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