How can I register History Entries (Back/Forward) in a Multiview (on Active Index changed)

Question

I'm using an update panel to have part of my page update asynchronously. Its navigation needs to be registered when a Multiview changes its active index.

For example, when the page first loads, the Multiview Active Index = 0. When user clicks on a link, I show the content of the View index 1.

It is really important to allow the user to go backward and forward using the browser history.

The ScriptManager is located in a master page and has its EnableHistory property set to True.

Has someone implemented it when working with Multiview?

Answer 1

I think this should work, but you'll need to customize it a bit. I'm doing something very similar, but I had to move away from using the multview within updatepanel due to a problem with a third-party control I had embedded within it.

You'll need to add a reference to your Master page in your aspx file using the asp.net tag below. And also, expose the scriptmanager as a public control in your master page so you can wire an event to it.

In your page's design/html code: Update the virtual path to your Master or use the Type to assign the type reference.

<%@ MasterType VirtualPath="~/MasterPage.master" %>

In your page's init event:

public void Page_Init(object sender, EventArgs e)
{
    // can be done at MasterPage level if you like
    this.Master.ScriptManager.EnableHistory = true;
}

Then in your page's load event:

protected void Page_Load(object sender, EventArgs e)
{              
    this.Master.ScriptManager.Navigate += 
    new EventHandler<HistoryEventArgs>(ScriptManager_Navigate);

    if (!this.IsPostBack && !ScriptManager.GetCurrent(this).IsInAsyncPostBack)
    {
        // load default multiview index
    }           
}

Then add this new event handler to your page. This names the item "myArgs", you should use something a bit more intuitive for your content. In my implementation, I have a series of items (like sort order, page index, etc. separated by delims and then break them up and assign them).

protected void ScriptManager_Navigate(object sender, HistoryEventArgs e)
{
    if (!string.IsNullOrEmpty(e.State["myArgs"]))
    {
        string args = e.State["myArgs"];
        SetMyArgs(args);                           
    }
    else
    {
        // just load default
    }
}

The args will be the multiview index. These are just helper functions that I use. If index is the only item you care about, then you can just inline these calls to the main methods.

private void SetMyArgs(string args)
{
    int myIndex = int.Parse(args);
    // set multiview index here?
}

private string GetMyArgs()
{
    return myMultiview.ActiveIndex.ToString();
}

Then when you trigger the event that changes the active index, add this to those methods

if (this.IsAsync)
{
    this.Master.ScriptManager.AddHistoryPoint("myArgs", GetMyArgs());
}

Hopefully, this gives you some help.