ApplicationDbContext.cs

public override int SaveChanges()
{
    // Soft-Delete 
    var entities = ChangeTracker.Entries()
        .Where(e => e.State == EntityState.Deleted && e.Metadata.GetProperties()
        .Any(x => x.Name == "IsDeleted"))
        .ToList();

    foreach (var entity in entities)
    {
        entity.State = EntityState.Unchanged;
        entity.CurrentValues["IsDeleted"] = true;
    }

    return base.SaveChanges();
}