ASP.Net/User Control and Master Page/Property
Содержание
Creating ViewState-Enabled Control Properties (C#)
<source lang="csharp">
<%@ Page language="C#" %> <%@ Register TagPrefix="Control" Namespace="Control" Assembly="Control" %> <script language="C#" runat="server"> void Page_Load(object sender, EventArgs e) {
if (!IsPostBack)
{
Random rand = new Random();
ViewStateControl1.Text = rand.Next(1,100).ToString();
}
} </script> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" > <html>
<head>
<title>Creating ViewState-Enabled Control Properties</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<Control:ViewStateControl id="ViewStateControl1" runat="server" />
<asp:linkbutton text="PostBack test" runat="server" />
</form>
</body>
</html> File: Control.cs using System; using System.Web.UI; using System.Web.UI.WebControls; using System.ruponentModel; namespace Control {
[DefaultProperty("Text"),
ToolboxData("<{0}:ViewStateControl runat=server></{0}:ViewStateControl>")]
public class ViewStateControl : System.Web.UI.WebControls.WebControl
{
public string Text
{
get
{
string text = (string) ViewState["Text"];
return (text == null)? string.Empty : text;
}
set
{
ViewState["Text"] = value;
}
}
protected override void Render(HtmlTextWriter writer)
{
writer.Write(Text);
}
}
}
</source>
Creating ViewState-Enabled Control Properties (VB)
<source lang="csharp">
<%@ Page language="VB" %> <%@ Register TagPrefix="Control" Namespace="Control" Assembly="Control" %> <script language="VB" runat="server"> Sub Page_Load(Sender As Object, E As EventArgs)
If Not IsPostBack Then Dim RandomGenerator As Random RandomGenerator = New Random(DateTime.Now.Millisecond) ViewStateControl1.Text = RandomGenerator.Next(1,100) End If
End Sub </script> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" > <html>
<body ms_positioning="GridLayout">
<form id="Form1" method="post" runat="server">
<Control:viewstatecontrol id="ViewStateControl1" runat="server" />
<asp:linkbutton text="PostBack test" runat="server" id="Linkbutton1" />
</form>
</body>
</html>
File: Default.vb Imports System Imports System.Web.UI Imports System.Web.UI.WebControls Imports System.ruponentModel Namespace Control
Public Class ViewStateControl
Inherits System.Web.UI.WebControls.WebControl
Public Property Text() As String
Get
Dim _text As String = CStr(ViewState("Text"))
If _text Is Nothing Then
Return String.Empty
Else
Return _text
End If
End Get
Set(ByVal Value As String)
ViewState("Text") = Value
End Set
End Property
Protected Overrides Sub Render(ByVal writer As HtmlTextWriter)
writer.Write(Text)
End Sub
End Class
End Namespace
</source>
User control with readonly properties
<source lang="csharp">
<%@ Page %> <%@ Register TagPrefix="uc1" TagName="header" Src="Control.ascx" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" > <HTML>
<HEAD>
<title>User Controls</title>
<Script language="C#" Runat="Server">
private void Page_Load(object sender, System.EventArgs e)
{
header1.Author = "Snoopy";
FooterLabel.Text = "Rendered " + header1.RenderDate;
}
</Script>
</HEAD>
<body>
<form id="dependingdropdowns" method="post" runat="server">
<uc1:header id="header1" runat="server" Title="A Tale of Mystery"></uc1:header>
It was a dark and stormy night.
<asp:Label ID="FooterLabel" Runat="server" /> </form> </body>
</HTML> File: Control.ascx <%@ Control Language="c#" %> <script runat="server"> private string title; private string author; private DateTime renderDate = System.DateTime.Now; public string Title {
get {
return title;
}
set {
title = value;
}
} public string Author {
get {
return author;
}
set {
author = value;
}
} // ReadOnly public DateTime RenderDate {
get {
return renderDate;
}
} private void Page_Load(object sender, EventArgs e) {
TitleLabel.Text = Title; AuthorLabel.Text = Author;
} </script>
