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Description
In ASP.NET Core, background tasks can be implemented as hosted services.
MyBackgroundService.cs
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public class MyBackgroundService(IServiceProvider services) : BackgroundService
{
protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
using (var scope = Services.CreateScope())
{
var scopedService = scope.ServiceProvider.GetRequiredService<IMyScopedService>();
await scopedService.DoWork(stoppingToken);
}
}
public override async Task StopAsync(CancellationToken stoppingToken)
{
await base.StopAsync(stoppingToken);
}
}
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Program.cs
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services.AddHostedService<MyBackgroundService>();
services.AddScoped<IMyScopedService, MyScopedService>();
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BackgroundTaskQueue
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public class BackgroundTaskQueue<T> : IBackgroundTaskQueue
{
private readonly ConcurrentQueue<T> items = new();
public void Enqueue(T item) => items.Enqueue(item);
public T? Dequeue()
{
var success = items.TryDequeue(out var workItem);
return success ? workItem : default;
}
}
public interface IBackgroundTaskQueue<T>
{
void Enqueue(T item);
T? Dequeue();
}
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QueuedHostedService.cs
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public class QueuedHostedService(IBackgroundTaskQueue taskQueue) : BackgroundService
{
public IBackgroundTaskQueue TaskQueue { get; } = taskQueue ;
protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
while (!stoppingToken.IsCancellationRequested)
{
var queuedTask = await TaskQueue.DequeueAsync(stoppingToken);
try
{
await queuedTask(stoppingToken);
}
catch (Exception ex)
{ }
}
}
}
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Program.cs
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services.AddHostedService<QueuedHostedService>();
services.AddSingleton<IBackgroundTaskQueue>(ctx =>
{
if (!int.TryParse(hostContext.Configuration["QueueCapacity"], out var queueCapacity))
queueCapacity = 100;
return new BackgroundTaskQueue(queueCapacity);
});
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