ABP.IO BackgroundWorker UOW 例外

紀錄 HangfireBackgroundWorkerBase 的坑

徵狀

Cannot access a disposed context instance
- 使用 HangfireBackgroundWorkerBase 發生例外
The Logger object is null
- 使用介面設定 Hangfire Worker UOW 發生例外
資料沒有更新到資料庫
- 記得 SaveChanges
- 更新資料須將查到的或新增的 Entity 回傳給之後更新用

示意圖

185554747 f5091008 8fbd 4eb3 ad0a be47dbb09133

結論

Worker.cs

使用類別

using Hangfire;
using Volo.Abp.BackgroundWorkers.Hangfire;
using Volo.Abp.DependencyInjection;
using Volo.Abp.Uow;

namespace T89NoUi.Workers;

public class UowModifiedWorker : HangfireBackgroundWorkerBase
    , IUowModifiedWorker
{
	private readonly OrderManager _orderManager;
    public UowModifiedWorker(OrderManager orderManager)
    {
        RecurringJobId = nameof(UowModifiedWorker);
        CronExpression = Cron.Minutely();
        _orderManager = orderManager;
    }

    public override async Task DoWorkAsync(
        CancellationToken cancellationToken = new CancellationToken())
    {
    	Logger.LogDebug("Executed {@Name} ..!",MethodBase.GetCurrentMethod());
        using var uow = LazyServiceProvider
            .LazyGetRequiredService<IUnitOfWorkManager>().Begin();
        await orderManager.SaveAsync();
        await uow.SaveChangesAsync(cancellationToken);
    }
}

使用介面

using Hangfire;
using Volo.Abp.BackgroundWorkers.Hangfire;
using Volo.Abp.DependencyInjection;
using Volo.Abp.Uow;

namespace T89NoUi.Workers;

public interface IUowModifiedWorker : IHangfireBackgroundWorker
{
}

[ExposeServices(typeof(IUowModifiedWorker), typeof(UowModifiedWorker))]
public class UowModifiedWorker : HangfireBackgroundWorkerBase
    , IUowModifiedWorker
{
    public UowModifiedWorker()
    {
        RecurringJobId = nameof(UowModifiedWorker);
        CronExpression = Cron.Minutely();
    }

    public override Task DoWorkAsync(
        CancellationToken cancellationToken = new CancellationToken())
    {
        using var uow = LazyServiceProvider
            .LazyGetRequiredService<IUnitOfWorkManager>().Begin();
        Logger.LogInformation($"Executed {nameof(UowModifiedWorker)} ..!");
        return Task.CompletedTask;
    }
}

Module.cs

public override async Task OnApplicationInitializationAsync(
    ApplicationInitializationContext context)
{
    await base.OnApplicationInitializationAsync(context);
    // 使用類別
    await context.AddBackgroundWorkerAsync<UowModifiedWorker>();

    // If the interface is defined
    // await context.AddBackgroundWorkerAsync<IUowModifiedWorker>();
}

Issue

The Logger object is null · Issue #12339 · abpframework/abp (github.com)

Doc

Background Workers Hangfire | Documentation Center | ABP.IO

PS5

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14 October 2025