首先，我们需要创建一个基于Timer的后台服务。然后，我们将在Startup.cs中注册他们，以便将它们添加到DI容器中。最后，我们使用IHostedService接口来启动和停止后台任务。

代码示例如下：

1.创建后台服务：

public class MyBackgroundService1 : BackgroundService
{
    private readonly ILogger _logger;

    public MyBackgroundService1(ILogger logger)
    {
        _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            _logger.LogInformation("MyBackgroundService1 is running.");

            await Task.Delay(TimeSpan.FromSeconds(10), stoppingToken);
        }
    }
}

public class MyBackgroundService2 : BackgroundService
{
    private readonly ILogger _logger;

    public MyBackgroundService2(ILogger logger)
    {
        _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            _logger.LogInformation("MyBackgroundService2 is running.");

            await Task.Delay(TimeSpan.FromSeconds(5), stoppingToken);
        }
    }
}

2.注册服务：

public void ConfigureServices(IServiceCollection services)
{
    // Add timer based background services
    services.AddHostedService();
    services.AddHostedService();
}

3.启动和停止服务：

public class MyHostedService : IHostedService
{
    private readonly IEnumerable _hostedServices;

    public MyHostedService(IEnumerable hostedServices)
    {
        _hostedServices = hostedServices;
    }

    public async Task StartAsync(CancellationToken cancellationToken)
    {
        foreach (var hostedService in _hostedServices)
        {
            await hostedService.StartAsync(cancellationToken);
        }
    }

    public async Task StopAsync(CancellationToken cancellationToken)
    {
        foreach (var hostedService in _hostedServices.Reverse())
        {
            await hostedService.StopAsync(cancellationToken);