tenantRepository.GetListAsync return error: object reference not set to an instance of an object #4061 | Support

zhongfang created 2 years ago

ABP Framework version: v6.0.1
UI type: Blazor
DB provider: EF Core
Tiered (MVC) or Identity Server Separated (Angular): no
Exception message and stack trace: System.NullReferenceException:“Object reference not set to an instance of an object.”
Steps to reproduce the issue:" 1)method in background worker 2)ITenantRepository tenantRepository = this.LazyServiceProvider.LazyGetRequiredService<ITenantRepository>(); 3)List<Tenant> allTenants = await tenantRepository.GetListAsync();

10 Answer(s)

0

maliming created 2 years ago
Support Team Fullstack Developer

hi

Can you share the code of background worker?

zhongfang created 2 years ago

public class FansJoinedNotifierWorkItem : AsyncPeriodicBackgroundWorkerBase
{
    public FansJoinedNotifierWorkItem(AbpAsyncTimer timer, IServiceScopeFactory serviceScopeFactory) : base(timer, serviceScopeFactory)
    {
        this.Timer.Period = 60 * 1000;
    }

    protected async override Task DoWorkAsync(PeriodicBackgroundWorkerContext workerContext)
    {
        this.Timer.Period = 1440 * 60 * 1000;

        扫码关注送积分 subscribPoint = new 扫码关注送积分();
        subscribPoint.LazyServiceProvider = this.LazyServiceProvider;
        await this.FansSubscribedPoint();
        
        this.Timer.Period = siteOptions.Value.UserFollowNotifyIntervalMinutes * 60 * 1000;
    }

    static List<Tenant> allTenants;
    public async Task FansSubscribedPoint()
    {
        Log.Information("Starting: 【扫码关注】积分发放...");
        
        IDataFilter dataFilter = this.LazyServiceProvider.LazyGetRequiredService<IDataFilter>();

        if (allTenants == null)
        {
            using (dataFilter.Disable<IMultiTenant>())
            {
                ITenantRepository tenantRepository = this.LazyServiceProvider.LazyGetRequiredService<ITenantRepository>();

                allTenants = await tenantRepository.GetListAsync();
            }
        }

        ……

        Log.Information("Completed: 【扫码关注】积分发放...");
    }
}

zhongfang created 2 years ago

and I try another way,

            ICurrentTenant currentTenant = this.LazyServiceProvider.LazyGetRequiredService&lt;ICurrentTenant&gt;();
            ITenantRepository tenantRepository = this.LazyServiceProvider.LazyGetRequiredService&lt;ITenantRepository&gt;();

            if (allTenants == null)
            {
                using (currentTenant.Change(null))
                {
                    allTenants = await tenantRepository.GetListAsync();
                }
            }

got the same error again: Object reference not set to an instance of an object.

0

maliming created 2 years ago
Support Team Fullstack Developer

Object reference not set to an instance of an object.

Full error stack?
0

zhongfang created 2 years ago

2022-11-17 11:10:23.791 +08:00 [INF] Starting: 【扫码关注】积分发放... 2022-11-17 11:10:46.619 +08:00 [ERR] Object reference not set to an instance of an object. System.NullReferenceException: Object reference not set to an instance of an object. at Yee.Change.AdminBlazorUI.WorkItems.FansJoinedNotifierWorkItem.FansSubscribedPoint() in D:\dev\abp\change\admin-blazor-ui\src\Yee.Change.AdminBlazorUI.Application\WorkItems\FansJoinedNotifierWorkItem.cs:line 97 at Yee.Change.AdminBlazorUI.WorkItems.FansJoinedNotifierWorkItem.DoWorkAsync(PeriodicBackgroundWorkerContext workerContext) in D:\dev\abp\change\admin-blazor-ui\src\Yee.Change.AdminBlazorUI.Application\WorkItems\FansJoinedNotifierWorkItem.cs:line 56 at Volo.Abp.BackgroundWorkers.AsyncPeriodicBackgroundWorkerBase.DoWorkAsync(CancellationToken cancellationToken) 2022-11-17 11:10:51.016 +08:00 [INF] Initialized all ABP modules.
0

maliming created 2 years ago
Support Team Fullstack Developer

Please set a breaking point to check which object is null/
0

zhongfang created 2 years ago

Oh...

ITenantRepository tenantRepository = this.LazyServiceProvider.LazyGetRequiredService<ITenantRepository>();

tenantRepository is null
0

maliming created 2 years ago
Support Team Fullstack Developer

Can you reproduce the problem in a new template project? liming.ma@volosoft.com
0

zhongfang created 2 years ago

No restrict to get the service of ITenantRepository?

Can I get the ITenantRepository anywhere especially in backgroun worker class?
0

maliming created 2 years ago
Support Team Fullstack Developer

We need to check the project.

https://support.abp.io/QA/Questions/4061#answer-1ab3be6e-393d-7ab9-13c2-3a0796233132

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