Asynchronus loading of visual web part

Question

I am developing a visual web part that will do some some heavy operations. It is a visual web part in SharePoint 2013, on premise.

I want to load my data asynch. Ajax toolkit is not compatible and gives problem, as far as I have heard and tried.

Any tips for how my web part can load asynch on this sample code?

This is my code in c#

  protected void Page_Load(object sender, EventArgs e)
    {
        GetCurrentUserData();
    }

    private void GetCurrentUserData()
    {
        try
        {
            var web = SPContext.Current.Web;
            var currentUser = web.CurrentUser.LoginName;
            var serverContext = SPServiceContext.GetContext(web.Site);
            var profileManager = new UserProfileManager(serverContext);
            var currentUserprofile = profileManager.GetUserProfile(currentUser);

            var displayName = currentUserprofile.DisplayName;
            LblName.Text = displayName;

            web.Dispose();
        }
        catch (Exception ex)
        {
            LblError.Text = "Exception.";
        }          
    }

This is my code in asp.net

<%@ Assembly Name="$SharePoint.Project.AssemblyFullName$" %>
<%@ Assembly Name="Microsoft.Web.CommandUI, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> 
<%@ Register Tagprefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> 
<%@ Register Tagprefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register Tagprefix="asp" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
<%@ Import Namespace="Microsoft.SharePoint" %> 
<%@ Register Tagprefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="WpProfilePropertiesUserControl.ascx.cs" Inherits="XX.MySite.SPI.WebParts.WpProfileProperties.WpProfilePropertiesUserControl" %>

<div>
    <asp:Label ID="LblError" runat="server" Text=""></asp:Label>
    <asp:Label ID="LblName" runat="server"></asp:Label> 
</div>

Answer 1

I wrote this code here so I can't guarantee it will work as is. It should get you pointed in the right direction.

private Func<string> _func;

protected void Page_Load(object sender, EventArgs e)
{
    _func = new Func<string>(GetCurrentUserData);

    Page.RegisterAsyncTask(
        new PageAsyncTask(
            new BeginEventHandler(BeginGetData),
            new EndEventHandler(EndGetData),
            new EndEventHandler(TimoutGetData),
            null, true));    
}

public IAsyncResult BeginGetData(object sender, EventArgs e, AsyncCallback cb, object state)
{
    return _func.BeginInvoke(cb, state);
}

public void EndGetData(IAsyncResult ar)
{
    var data = _func.EndInvoke(ar);
    LblName.Text = data;
}

public void TimoutGetData(IAsyncResult ar)
{
    LblError.Text = "Timeout.";
}

private string GetCurrentUserData()
{
    try
    {
        var web = SPContext.Current.Web;
        var currentUser = web.CurrentUser.LoginName;
        var serverContext = SPServiceContext.GetContext(web.Site);
        var profileManager = new UserProfileManager(serverContext);
        var currentUserprofile = profileManager.GetUserProfile(currentUser);

        return currentUserprofile.DisplayName;
    }
    catch (Exception ex)
    {
        return ex.Message;
    }          
}

I discuss this pattern at around the 52 minute mark of this recording of Advanced SharePoint Web Part Development. In the video I use a delegate instead of a lambda but the pattern is the same.