Using the ASP.NET UpdatePanel Control with Master Pages

Articolo
10/22/2014

Any ASP.NET page that includes an UpdatePanel control also requires a ScriptManager control. To use UpdatePanel controls with master pages, you can put a ScriptManager control on the master page. In this scenario, the master page provides a ScriptManager control for every content page. If you do not want partial-page updates enabled for individual content pages, you can disable partial-page updates for those pages.

Alternatively, you can put the ScriptManager control on each content page. You might do this if only some of the content pages will contain UpdatePanel controls.

Prerequisites

To implement the procedures in your own development environment you need:

Visual Web Developer Express or Microsoft Visual Studio 2005.
An AJAX-enabled ASP.NET Web site.

To add an UpdatePanel control to a content page

Create a new master page and switch to Design view.
In the AJAX Extensions tab of the toolbox, double-click the ScriptManager control to add it to the page. Make sure that you add the ScriptManager control outside the ContentPlaceHolder control.
Outside the ContentPlaceHolder control, add the text Master Page.
From the HTML tab of the toolbox, drag a Horizontal Rule element after the text.
Create a content page for the master page.

In Solution Explorer, right-click the name of the project, and then click Add New Item. In the Add New Item dialog box, select the Select master page check box, and then click OK.
Inside the Content control, type the text Content Page and then from the toolbox add an UpdatePanel control.
Add a Calendar control inside the UpdatePanel control.
Save your changes and then press CTRL+F5 view the page in a browser.

Click the next and previous month controls on the calendar.

The calendar changes without refreshing the whole page. This behavior is what you expect when the calendar is inside a UpdatePanel control on a page that is not associated with a master page.

The example is styled to better show the region of the page that the UpdatePanel control represents.

<%@ Page Language="VB" MasterPageFile="MasterPage.master" Title="UpdatePanel in Master Pages" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    Content Page<br />
    <asp:UpdatePanel id="UpdatePanel1" runat="server">
        <contenttemplate>
        <fieldset>
        <legend>UpdatePanel</legend>
           <asp:Calendar id="Calendar1" runat="server"></asp:Calendar>
        </fieldset>
        </contenttemplate>
    </asp:UpdatePanel>
</asp:Content>

<%@ Page Language="C#" MasterPageFile="MasterPage.master" Title="UpdatePanel in Master Pages" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    Content Page<br />
    <asp:UpdatePanel id="UpdatePanel1" runat="server">
        <contenttemplate>
        <fieldset>
        <legend>UpdatePanel</legend>
           <asp:Calendar id="Calendar1" runat="server"></asp:Calendar>
        </fieldset>
        </contenttemplate>
    </asp:UpdatePanel>
</asp:Content>

<%@ Master Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>UpdatePanel in Master Pages</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        Master Page<br />
        <hr />
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <br />
        <asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
        </asp:contentplaceholder>
    </div>
    </form>
</body>
</html>

<%@ Master Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>UpdatePanel in Master Pages</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        Master Page<br />
        <hr />
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <br />
        <asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
        </asp:contentplaceholder>
    </div>
    </form>
</body>
</html>

Refreshing the UpdatePanel from the Master Page

In this part of the tutorial you will add controls to the master page that cause an asynchronous postback and then refresh the UpdatePanel control on the content page.

To enable partial-page updates for all content pages

In the master page, switch to Design view.
Add text and two buttons after the ScriptManager control on the master page.
Set the ID of one button to DecrementButton and its Text value to "-". Set the ID of the other button to IncrementButton and set its Text value to "+".

The buttons will increment and decrement the selected date on the calendar in the content page.
Select the + (plus) button, and then in the toolbar of the Properties window, click the Events button and enter MasterButton_Click in the Click box.
Repeat the previous step for the - (minus) button.
Double-click the page outside the controls to create a Page_Load event handler.

Add the following code in the handler to register the two buttons as asynchronous postback controls:

Protected Sub Page_Load(ByVal Sender As Object, ByVal E As EventArgs)
    ScriptManager1.RegisterAsyncPostBackControl(DecrementButton)
    ScriptManager1.RegisterAsyncPostBackControl(IncrementButton)
End Sub

protected void Page_Load(object sender, EventArgs e)
{
    ScriptManager1.RegisterAsyncPostBackControl(DecrementButton);
    ScriptManager1.RegisterAsyncPostBackControl(IncrementButton);
}

Add the following code to create a Click handler named MasterButton_Click:

Protected Sub MasterButton_Click(ByVal Sender As Object, ByVal E As EventArgs)

    Select Case Sender.ID

        Case "IncrementButton"
            Me.Offset = Me.Offset + 1
        Case "DecrementButton"
            Me.Offset = Me.Offset - 1
    End Select
    Dim upl As UpdatePanel
    upl = ContentPlaceHolder1.FindControl("UpdatePanel1")
    upl.Update()
    Dim cal As Calendar
    cal = ContentPlaceHolder1.FindControl("Calendar1")
    Dim newDateTime As DateTime
    newDateTime = DateTime.Today.Add(New TimeSpan(Offset, 0, 0, 0))
    cal.SelectedDate = newDateTime
End Sub

protected void MasterButton_Click(object sender, EventArgs e)
{   
    switch (((Control)sender).ID)
    {
        case "IncrementButton":
            this.Offset = this.Offset + 1;
            break;
        case "DecrementButton":
            this.Offset = this.Offset - 1;
            break;
    }
    ((UpdatePanel)ContentPlaceHolder1.FindControl("UpdatePanel1")).Update();
    Calendar cal = ((Calendar)ContentPlaceHolder1.FindControl("Calendar1"));
    DateTime newDateTime = DateTime.Today.Add(new TimeSpan(Offset, 0, 0, 0));
    cal.SelectedDate = newDateTime;
}

Add the following code to create a public property named Offset in the master page that tracks the difference between today's date and the selected date.

Public Property Offset() As Integer
    Get
        If ViewState("Offset") Is Nothing Then
            Return 0
        Else : Return ViewState("Offset")
        End If
    End Get
    Set(ByVal value As Integer)
        ViewState("Offset") = value
    End Set
End Property

public Int32 Offset
{
    get
    { return (Int32)(ViewState["Offset"] ?? 0);}
    set
    { ViewState["Offset"] = value;}
}

In the content page, switch to Design view and then double-click the Calendar control to create an event handler for the SelectionChanged event.

Add the following code to the SelectionChanged event handler to set the Offset property when the user selects a date.

Protected Sub Calendar1_SelectionChanged(ByVal Sender As Object, ByVal E As EventArgs)
    Dim selectedDate As DateTime
    selectedDate = Calendar1.SelectedDate
    Master.Offset = _
       Calendar1.SelectedDate.Subtract(DateTime.Today).Days

End Sub

protected void Calendar1_SelectionChanged(object sender, 
    EventArgs e)
{
    DateTime selectedDate = Calendar1.SelectedDate;
    Master.Offset =
       ((TimeSpan)Calendar1.SelectedDate.Subtract(
       DateTime.Today)).Days;
}

Switch to the content page and add a Page_Load event handler that sets the selected date of the calendar to the current date.

Protected Sub Page_Load(ByVal Sender As Object, ByVal E As EventArgs)
    Dim newDateTime As DateTime
    newDateTime = DateTime.Today.Add(New TimeSpan(Master.Offset, 0, 0, 0))
    Calendar1.SelectedDate = newDateTime
End Sub

protected void Page_Load(object sender, EventArgs e)
{
    DateTime newDateTime = 
        DateTime.Today.Add(new 
        TimeSpan(Master.Offset, 0, 0, 0));
    Calendar1.SelectedDate = newDateTime;
}

Add an @ MasterType directive to the page so that you can refer to the master page Offset property as a strongly typed property.
```
<%@ MasterType VirtualPath="MasterPage.master" %>
```
```
<%@ MasterType VirtualPath="MasterPage.master" %>
```
In the content page, switch to Design view and select the UpdatePanel control.
In the Properties window, set the UpdatePanelUpdateMode property to Conditional.
Save your changes and then press CTRL+F5 view the page in a browser.
Click the next and previous month controls on the calendar.

The calendar changes without refreshing the whole page.

Select a date on the calendar and then click the buttons on the master page to change the selected date.

These changes occur without refreshing the whole page.

The example is styled to better show the region of the page that the UpdatePanel control represents.

<%@ Page Language="VB" MasterPageFile="MasterPage.master" Title="UpdatePanel in Master Pages" %>
<%@ MasterType VirtualPath="MasterPage.master" %>

<script runat="server">
    Protected Sub Page_Load(ByVal Sender As Object, ByVal E As EventArgs)
        Dim newDateTime As DateTime
        newDateTime = DateTime.Today.Add(New TimeSpan(Master.Offset, 0, 0, 0))
        Calendar1.SelectedDate = newDateTime
    End Sub
    Protected Sub Calendar1_SelectionChanged(ByVal Sender As Object, ByVal E As EventArgs)
        Dim selectedDate As DateTime
        selectedDate = Calendar1.SelectedDate
        Master.Offset = _
           Calendar1.SelectedDate.Subtract(DateTime.Today).Days

    End Sub
</script>

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    Content Page<br />
    <asp:UpdatePanel id="UpdatePanel1" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
        <fieldset>
        <legend>UpdatePanel</legend>
           <asp:Calendar id="Calendar1" runat="server" OnSelectionChanged="Calendar1_SelectionChanged"></asp:Calendar> 
        </fieldset>
        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

<%@ Page Language="C#" MasterPageFile="MasterPage.master" Title="UpdatePanel in Master Pages" %>
<%@ MasterType VirtualPath="MasterPage.master" %>

<script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        DateTime newDateTime = 
            DateTime.Today.Add(new 
            TimeSpan(Master.Offset, 0, 0, 0));
        Calendar1.SelectedDate = newDateTime;
    }
    protected void Calendar1_SelectionChanged(object sender, 
        EventArgs e)
    {
        DateTime selectedDate = Calendar1.SelectedDate;
        Master.Offset =
           ((TimeSpan)Calendar1.SelectedDate.Subtract(
           DateTime.Today)).Days;
    }
</script>

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    Content Page<br />
    <asp:UpdatePanel id="UpdatePanel1" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
        <fieldset>
        <legend>UpdatePanel</legend>
           <asp:Calendar id="Calendar1" runat="server" OnSelectionChanged="Calendar1_SelectionChanged"></asp:Calendar> 
        </fieldset>
        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

<%@ Master Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
    Public Property Offset() As Integer
        Get
            If ViewState("Offset") Is Nothing Then
                Return 0
            Else : Return ViewState("Offset")
            End If
        End Get
        Set(ByVal value As Integer)
            ViewState("Offset") = value
        End Set
    End Property
    Protected Sub MasterButton_Click(ByVal Sender As Object, ByVal E As EventArgs)

        Select Case Sender.ID

            Case "IncrementButton"
                Me.Offset = Me.Offset + 1
            Case "DecrementButton"
                Me.Offset = Me.Offset - 1
        End Select
        Dim upl As UpdatePanel
        upl = ContentPlaceHolder1.FindControl("UpdatePanel1")
        upl.Update()
        Dim cal As Calendar
        cal = ContentPlaceHolder1.FindControl("Calendar1")
        Dim newDateTime As DateTime
        newDateTime = DateTime.Today.Add(New TimeSpan(Offset, 0, 0, 0))
        cal.SelectedDate = newDateTime
    End Sub
    Protected Sub Page_Load(ByVal Sender As Object, ByVal E As EventArgs)
        ScriptManager1.RegisterAsyncPostBackControl(DecrementButton)
        ScriptManager1.RegisterAsyncPostBackControl(IncrementButton)
    End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>UpdatePanel in Master Pages</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        Master Page<br />
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        Change date &nbsp;
        <asp:Button ID="DecrementButton" runat="server" Text="-" OnClick="MasterButton_Click" />
        <asp:Button ID="IncrementButton" runat="server" Text="+" OnClick="MasterButton_Click" />
        <hr />
        <br />
        <asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
        </asp:contentplaceholder>
    </div>
    </form>
</body>
</html>

<%@ Master Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
    public Int32 Offset
    {
        get
        { return (Int32)(ViewState["Offset"] ?? 0);}
        set
        { ViewState["Offset"] = value;}
    }
    protected void MasterButton_Click(object sender, EventArgs e)
    {   
        switch (((Control)sender).ID)
        {
            case "IncrementButton":
                this.Offset = this.Offset + 1;
                break;
            case "DecrementButton":
                this.Offset = this.Offset - 1;
                break;
        }
        ((UpdatePanel)ContentPlaceHolder1.FindControl("UpdatePanel1")).Update();
        Calendar cal = ((Calendar)ContentPlaceHolder1.FindControl("Calendar1"));
        DateTime newDateTime = DateTime.Today.Add(new TimeSpan(Offset, 0, 0, 0));
        cal.SelectedDate = newDateTime;
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        ScriptManager1.RegisterAsyncPostBackControl(DecrementButton);
        ScriptManager1.RegisterAsyncPostBackControl(IncrementButton);
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>UpdatePanel in Master Pages</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        Master Page<br />
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        Change date &nbsp;
        <asp:Button ID="DecrementButton" runat="server" Text="-" OnClick="MasterButton_Click" />
        <asp:Button ID="IncrementButton" runat="server" Text="+" OnClick="MasterButton_Click" />
        <hr />
        <br />
        <asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
        </asp:contentplaceholder>
    </div>
    </form>
</body>
</html>

Disabling Partial-Page Updates for a Content Page

If you add a ScriptManager control to a master page, by default partial-page updates are enabled for all content pages. If do not want to enable partial updates for an individual content page, you can disable that capability. You might do this is if your content page contains custom controls that are not compatible with partial-page updates.

To disable partial-page updates for a content page

In the content page, create a handler for the page's Init event that sets the ScriptManager control's EnablePartialRendering property to false.

You must change the state of the EnablePartialRendering property during or before the content page's Init event.

Review

This tutorial shows how to use an UpdatePanel control in master pages. If there is a ScriptManager control on the master page, you can use UpdatePanel controls on content pages without declaring a ScriptManager control in the content page.

To disable partial-page rendering for an individual content page whose master page has partial-page rendering enabled, programmatically disable partial-page rendering for the content page.

Condividi tramite

Using the ASP.NET UpdatePanel Control with Master Pages

Prerequisites

To add an UpdatePanel control to a content page

Refreshing the UpdatePanel from the Master Page

To enable partial-page updates for all content pages

Disabling Partial-Page Updates for a Content Page

To disable partial-page updates for a content page

Review

See Also

Tasks

Concepts

Reference

Risorse aggiuntive