如何检查.net核心2.1MVC中是否有记录更改

<ItemGroup>
  <PackageReference Include="Microsoft.EntityFrameworkCore" Version="2.1.0" />
  <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.1.0" />
  <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="2.1.0" />
</ItemGroup>

using Microsoft.EntityFrameworkCore;

public class YourDbContext : DbContext
{
    public DbSet<YourEntity> YourEntities { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        // 配置实体和数据库表之间的映射关系
        modelBuilder.Entity<YourEntity>().ToTable("YourTableName");
    }

    public override int SaveChanges()
    {
        // 在保存更改之前检查是否有记录更改
        var modifiedEntities = ChangeTracker.Entries()
            .Where(e => e.State == EntityState.Modified)
            .Select(e => e.Entity);

        // 对于每个修改的实体，你可以执行相应的操作
        foreach (var entity in modifiedEntities)
        {
            // 执行你的记录更改的逻辑
            // 例如，可以将更改记录到日志文件或发送通知
        }

        return base.SaveChanges();
    }
}