ASP.NET Tutorial/ASP.net Controls/HiddenField
Содержание
Hidden fields and ViewState (C#)
<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!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">
<title>Hidden Fields and ViewState</title>
</head> <body>
<form id="form1" runat="server">
<asp:TextBox ID="TextBox1" Runat="server"></asp:TextBox>
<asp:Button ID="Button1" Runat="server" Text="Button" />
<asp:HiddenField ID="HiddenField1" Runat="server" />
</form>
</body> </html>
File: Default.aspx.cs using System; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; [Serializable] public class Person {
public string firstName; public string lastName;
} public partial class _Default : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
HiddenField1.Value = "foo";
ViewState["AnotherHiddenValue"] = "bar";
Person p = new Person();
p.firstName = "Scott";
p.lastName = "Hanselman";
ViewState["HiddenPerson"] = p;
}
}
}</source>
Hidden fields and ViewState (VB)
<source lang="csharp">
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %> <!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">
<title>Hidden Fields and ViewState</title>
</head> <body>
<form id="form1" runat="server">
<asp:TextBox ID="TextBox1" Runat="server"></asp:TextBox>
<asp:Button ID="Button1" Runat="server" Text="Button" />
<asp:HiddenField ID="HiddenField1" Runat="server" />
</form>
</body> </html> File: Default.aspx.vb <Serializable()> _ Public Class Person
Public firstName As String Public lastName As String
End Class Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) _
Handles Me.Load
If Not Page.IsPostBack Then
HiddenField1.Value = "foo"
ViewState("AnotherHiddenValue") = "bar"
Dim p As New Person
p.firstName = "Scott"
p.lastName = "Hanselman"
ViewState("HiddenPerson") = p
End If
End Sub
End Class</source>
<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true"
CodeFile="Default.aspx.cs" Inherits="HiddenFieldTest" %>
<!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">
<title>HiddenField Test</title>
<style type="text/css">
#left { float: left; width: 200px; }
#right { float: right; width: 200px; }
</style>
</head> <body>
<form id="form1" runat="server">
HiddenField Test
Click multiple times on these two images
<asp:ImageButton ID="ibtnImage1"
runat="server"
ImageUrl="http://www.nfex.ru/style/logo.png"
AlternateText="Click on me"
OnClick="ibtnImage1_Click" />
<asp:Label ID="labMessage1" runat="server" />
<asp:ImageButton ID="ibtnImage2"
runat="server"
ImageUrl="http://www.nfex.ru/style/logo.png"
AlternateText="Click on me"
OnClick="ibtnImage2_Click" />
<asp:Label ID="labMessage2" runat="server" />
<asp:HiddenField ID="hfImage1" runat="server" />
<asp:HiddenField ID="hfImage2" runat="server" />
</form>
</body> </html> File: Default.aspx.cs using System; using System.Data; using System.Configuration; using System.Collections; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class HiddenFieldTest : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
hfImage1.Value = "0";
hfImage2.Value = "0";
}
}
protected void ibtnImage1_Click(object sender, EventArgs e)
{
IncrementCount(hfImage1);
labMessage1.Text = "# Clicks: " + hfImage1.Value;
}
protected void ibtnImage2_Click(object sender, EventArgs e)
{
IncrementCount(hfImage2);
labMessage2.Text = "# Clicks: " + hfImage2.Value;
}
private void IncrementCount(HiddenField hf)
{
int count = Convert.ToInt32(hf.Value);
count++;
hf.Value = count.ToString();
}
}</source>
Working with the HiddenField server control (C#)
<source lang="csharp">
<%@ Page Language="C#"%> <script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
HiddenField1.Value = System.Guid.NewGuid().ToString();
}
</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server">
<title>HiddenField Server Control</title>
</head> <body>
<form id="form1" runat="server">
<asp:HiddenField ID="HiddenField1" Runat="Server" />
</form>
</body> </html></source>
Working with the HiddenField server control (VB)
<source lang="csharp">
<%@ Page Language="VB" %> <script runat="server" language="vb">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
HiddenField1.Value = System.Guid.NewGuid().ToString()
End Sub
</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server">
<title>HiddenField Server Control</title>
</head> <body>
<form id="form1" runat="server">
<asp:HiddenField ID="HiddenField1" Runat="Server" />
</form>
</body> </html></source>
