如果服务未注册,我的方法不应调用ApplyAsync()。我试图添加条件null,但在调用该方法的时候仍然会得到空引用。我做错了什么吗?
private static async Task ApplyMigrationsAsync(CancellationToken token)
{
using var scope = Startup.ServiceProvider.CreateScope();
var migration = scope.ServiceProvider.GetService<M.Migrations.IMigration>();
await migration?.ApplyAsync(token);
}