NullReferenceException in MainHeader from Lepton Theme #8193 | Support

bmulinari created one month ago

ABP Framework version: v8.3.2
UI Type: Blazor Server
Database System: EF Core (SQL Server)
Exception message and full stack trace:
[16:42:28 ERR] Unhandled exception in circuit 'KGhlNtd6BxqzxILhhuZShTmKcJAZivA0bBCtrDKhcKU'. System.AggregateException: One or more errors occurred. (Object reference not set to an instance of an object.) ---> System.NullReferenceException: Object reference not set to an instance of an object. at Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout.MainHeader.MainHeader.i2Wswldy3T() at Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout.MainHeader.MainHeader.OnAfterRenderAsync(Boolean firstRender) --- End of inner exception stack trace ---
Steps to reproduce the issue:
Run the blazor server host and refresh the page a few times, the error seems to occur at random about 50% of the times (possible race condition?). The error can be seen in the browser console and in the app console.

This issue seems to be the same as reported in this issue in GitHub, but I couldn't find a solution (I also asked there).

10 Answer(s)

0

maliming created one month ago
Support Team Fullstack Developer

hi

Can you share your test project via https://wetransfer.com/?

liming.ma@volosoft.com

Thanks.
0

bmulinari created one month ago

I sent you an email.

Thanks!
0

maliming created one month ago
Support Team Fullstack Developer

ok, I will check it, thanks.
0

maliming created one month ago
Support Team Fullstack Developer

hi

We will fix this in 8.3.3.

Your ticket has been refunded.

1
0

bmulinari created one month ago

Thank you. Are there any workarounds we could use for fixing this issue until we wait for the next release?

maliming created one month ago

Support Team Fullstack Developer

Use the MyMainHeader.razor.cs and MyMainHeader.razor to override MainHeader

MyMainHeader.razor.cs

using System.Threading.Tasks;
using Microsoft.AspNetCore.Components;
using Volo.Abp.AspNetCore.Components.Web;
using Volo.Abp.LeptonTheme.Management;

namespace Cns.Modules.Docusign.Blazor.Server.Host.Pages;

public partial class MyMainHeader
{
    [Inject]
    private IAbpUtilsService UtilsService { get; set; }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            if (Menu != null)
            {
                if (Menu.Placement == MenuPlacement.Top)
                {
                    await UtilsService.AddClassToTagAsync("body", "lp-topmenu");
                }
                else
                {
                    if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
                    {
                        await UtilsService.AddClassToTagAsync("body", "lp-closed");
                        await UtilsService.RemoveClassFromTagAsync("body", "lp-opened-sidebar");
                        await UtilsService.RemoveClassFromTagAsync("body", "lp-body-fixed");
                    }
                    else
                    {
                        await UtilsService.RemoveClassFromTagAsync("body", "lp-closed");
                        await UtilsService.AddClassToTagAsync("body", "lp-opened-sidebar");
                        await UtilsService.AddClassToTagAsync("body", "lp-body-fixed");
                    }
                }
            }

            await InvokeAsync(StateHasChanged);
        }
    }

    async Task MyToggleNavbarStatusAsync()
    {
        if (Menu != null)
        {
            Menu.ToggleNavbarStatus();

            if (Menu.Placement == MenuPlacement.Top)
            {
                await UtilsService.AddClassToTagAsync("body", "lp-topmenu");
            }
            else
            {
                if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
                {
                    await UtilsService.AddClassToTagAsync("body", "lp-closed");
                    await UtilsService.RemoveClassFromTagAsync("body", "lp-opened-sidebar");
                    await UtilsService.RemoveClassFromTagAsync("body", "lp-body-fixed");
                }
                else
                {
                    await UtilsService.RemoveClassFromTagAsync("body", "lp-closed");
                    await UtilsService.AddClassToTagAsync("body", "lp-opened-sidebar");
                    await UtilsService.AddClassToTagAsync("body", "lp-body-fixed");
                }
            }
        }
    }

    protected virtual async Task OnNavBarMouseOverAsync()
    {
        //TODO: MOUSEOVER IS NOT PERFORMANT, WE SHOULD USE MOUSEENTER/MOUSELEAVE

        if (Menu != null)
        {
            if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
            {
                if (await UtilsService.HasClassOnTagAsync("body", "lp-closed"))
                {
                    await UtilsService.AddClassToTagAsync("body", "lp-extended");
                }
            }
        }
    }

    protected virtual async Task OnNavbarMouseOutAsync()
    {
        if (Menu != null)
        {
            if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
            {
                if (await UtilsService.HasClassOnTagAsync("body", "lp-closed"))
                {
                    await UtilsService.RemoveClassFromTagAsync("body", "lp-extended");
                }
            }
        }
    }
    protected virtual void ToggleToolbarNav()
    {
        IsToolbarNavShown = !IsToolbarNavShown;
    }

    protected virtual void ToggleSidebarNav()
    {
        IsSidebarNavShown = !IsSidebarNavShown;
    }

}

MyMainHeader.razor

@using Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout.Navigation
@using Volo.Abp.DependencyInjection
@using Volo.Abp.LeptonTheme.Management
@using Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout.MainHeader

@inherits Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout.MainHeader.MainHeader
@attribute [Dependency(ReplaceServices = true)]
@attribute [ExposeServices(typeof(Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout.MainHeader.MainHeader))]

<header>
    <MainHeaderBranding/>
    <nav class="navbar navbar-expand-xl navbar-dark d-lg-none nav-mobile">
        <button @onclick="ToggleToolbarNav" class="navbar-toggler border-0" type="button" data-bs-toggle="collapse" data-bs-target="#navbarToolbar" aria-controls="navbarText" aria-expanded="false" aria-label="Toggle navigation">
            <i class="fa fa-user"></i>
        </button>
        <button @onclick="ToggleSidebarNav" class="navbar-toggler border-0" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSidebar" aria-controls="navbarText" aria-expanded="false" aria-label="Toggle navigation">
            <i class="fa fa-align-justify"></i>
        </button>
    </nav>
    <nav class="navbar navbar-expand-lg user-nav-mobile">
        <div class="collapse navbar-collapse d-lg-block toolbar-nav-wrapper @(IsToolbarNavShown ? "show" : "")" id="navbarToolbar">
            <ul class="navbar-nav toolbar-nav ms-auto">
                <MainHeaderToolbar/>
            </ul>
        </div>
    </nav>
    <div class="lp-sidebar collapse navbar-collapse d-lg-block @(IsSidebarNavShown ? "show" : "")" id="navbarSidebar" @onmouseover="OnNavBarMouseOverAsync" @onmouseout="OnNavbarMouseOutAsync">
        <div class="lp-sidebar-header">
            <div class="lp-toggle-sidebar" @onclick="MyToggleNavbarStatusAsync">
                <i class="fa fa-align-left material-icons lp-open-icon"></i>
                <i class="fa fa-align-justify material-icons lp-close-icon"></i>
            </div>
        </div>
        <div class="lp-sidebar-wrapper">
            <MainSiderbar/>
        </div>
    </div>
</header>

0

bmulinari created one month ago

Thank you. Just a feedback: while your workaround prevents the exception from throwing, the layout is sometimes broken as shown below:

maliming created one month ago

Support Team Fullstack Developer

MyMainHeader.razor.cs

using System.Threading.Tasks;
using Microsoft.AspNetCore.Components;
using Volo.Abp.AspNetCore.Components.Web;
using Volo.Abp.LeptonTheme.Management;

namespace Cns.Modules.Docusign.Blazor.Server.Host.Pages;

public partial class MyMainHeader
{
    [Inject]
    private IAbpUtilsService UtilsService { get; set; }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            Menu ??= await MainMenuProvider.GetMenuAsync();
            if (Menu.Placement == MenuPlacement.Top)
            {
                await UtilsService.AddClassToTagAsync("body", "lp-topmenu");
            }
            else
            {
                if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
                {
                    await UtilsService.AddClassToTagAsync("body", "lp-closed");
                    await UtilsService.RemoveClassFromTagAsync("body", "lp-opened-sidebar");
                    await UtilsService.RemoveClassFromTagAsync("body", "lp-body-fixed");
                }
                else
                {
                    await UtilsService.RemoveClassFromTagAsync("body", "lp-closed");
                    await UtilsService.AddClassToTagAsync("body", "lp-opened-sidebar");
                    await UtilsService.AddClassToTagAsync("body", "lp-body-fixed");
                }
            }

            await InvokeAsync(StateHasChanged);
        }
    }

    async Task MyToggleNavbarStatusAsync()
    {
        Menu ??= await MainMenuProvider.GetMenuAsync();
        Menu.ToggleNavbarStatus();

        if (Menu.Placement == MenuPlacement.Top)
        {
            await UtilsService.AddClassToTagAsync("body", "lp-topmenu");
        }
        else
        {
            if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
            {
                await UtilsService.AddClassToTagAsync("body", "lp-closed");
                await UtilsService.RemoveClassFromTagAsync("body", "lp-opened-sidebar");
                await UtilsService.RemoveClassFromTagAsync("body", "lp-body-fixed");
            }
            else
            {
                await UtilsService.RemoveClassFromTagAsync("body", "lp-closed");
                await UtilsService.AddClassToTagAsync("body", "lp-opened-sidebar");
                await UtilsService.AddClassToTagAsync("body", "lp-body-fixed");
            }
        }
    }

    protected virtual async Task OnNavBarMouseOverAsync()
    {
        //TODO: MOUSEOVER IS NOT PERFORMANT, WE SHOULD USE MOUSEENTER/MOUSELEAVE

        Menu ??= await MainMenuProvider.GetMenuAsync();
        if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
        {
            if (await UtilsService.HasClassOnTagAsync("body", "lp-closed"))
            {
                await UtilsService.AddClassToTagAsync("body", "lp-extended");
            }
        }
    }

    protected virtual async Task OnNavbarMouseOutAsync()
    {
        Menu ??= await MainMenuProvider.GetMenuAsync();
        if (Menu.NavBarStatus == MenuStatus.OpenOnHover)
        {
            if (await UtilsService.HasClassOnTagAsync("body", "lp-closed"))
            {
                await UtilsService.RemoveClassFromTagAsync("body", "lp-extended");
            }
        }
    }
    protected virtual void ToggleToolbarNav()
    {
        IsToolbarNavShown = !IsToolbarNavShown;
    }

    protected virtual void ToggleSidebarNav()
    {
        IsSidebarNavShown = !IsSidebarNavShown;
    }
}

0

bmulinari created one month ago

Hi there. I see that 8.3.3 is out, but I couldn't find a mention of this in the release notes. Could you please confirm whether this issue was fixed in this release?
0

maliming created one month ago
Support Team Fullstack Developer

hi

8.3.3 will fix your problem. you can give it a try.

Thanks.

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