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Microsoft.EntityFrameworkCore新的版本不支持FrameWork框架。
这里举例使用旧版本实现数据存取
首先下载
Microsoft.EntityFrameworkCore 版本控制在2.1.14以下
同样下载Microsoft.EntityFrameworkCore.sqlite

举例时间记录

 public class RunTimeInfo{[Key]public int Id { get; set; }[Description("统计小时")]public DateTime TimeInfo { get; set; }[Description("运行时间")]public string RunTime { get; set; }public RunTimeInfo Clone(){return new RunTimeInfo(){TimeInfo = this.TimeInfo,RunTime = this.RunTime};}}

 public class DynamicModelCacheKeyFactoryRun : IModelCacheKeyFactory{public object Create(DbContext context)=> context is EfContextRunInfo dynamicContext? (context.GetType(), dynamicContext.CreateDateTime): (object)context.GetType();}

 public class EfContextRunInfo : DbContext{public DateTime CreateDateTime { get; set; }public static string connectionString{get{return $"Data Source={Environment.CurrentDirectory}\\RunTime\\{DateTime.Now.ToString("yyyy-MM-dd")}.db";}}public bool IsSave = true;public string DynamicConnectionString;public DbSet<RunTimeInfo> MdDatas { get; set; }public EfContextRunInfo(){}protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder){if (!optionsBuilder.IsConfigured){optionsBuilder.UseSqlite(IsSave ? connectionString : DynamicConnectionString).ReplaceService<IModelCacheKeyFactory, DynamicModelCacheKeyFactoryRun>();}}protected override void OnModelCreating(ModelBuilder modelBuilder){modelBuilder.Entity<RunTimeInfo>(entity =>{entity.ToTable(CreateDateTime.ToString("yyyyMMdd"));entity.Property(e => e.Id).IsRequired().HasColumnName("Id").HasColumnType("INTEGER").ValueGeneratedOnAdd();entity.Property(e => e.TimeInfo).IsRequired().HasColumnName("TimeInfo").HasColumnType("DATETIME");entity.Property(e => e.RunTime).IsRequired().HasColumnName("RunTime").HasColumnType("TEXT");entity.HasKey("Id");});}}

添加数据，查找数据

  static ConcurrentQueue<RunTimeInfo> runTimeInfo = new ConcurrentQueue<RunTimeInfo>();public Form1(){InitializeComponent();}private void btnSave_Click(object sender, EventArgs e){AddRunTimeData();}public static bool AddRunTimeData(){using (EfContextRunInfo context = new EfContextRunInfo { CreateDateTime = DateTime.Now }){try{if (!Directory.Exists($"{Environment.CurrentDirectory}\\RunTime\\")){// 文件夹不存在则创建Directory.CreateDirectory($"{Environment.CurrentDirectory}\\RunTime\\");}context.Database.EnsureCreated();//RelationalDatabaseCreator databaseCreator = (RelationalDatabaseCreator)context.Database.GetService<IDatabaseCreator>();//databaseCreator.CreateTables();}catch (Microsoft.Data.Sqlite.SqliteException ex){//Logger.Debug(ex.Message);}catch (Exception ex){MessageBox.Show(ex.Message);return false;}while (runTimeInfo.TryDequeue(out var mdData)){context.MdDatas.Add(mdData);}context.SaveChangesAsync();}return true;}private void btnAddData_Click(object sender, EventArgs e){runTimeInfo.Enqueue(new RunTimeInfo() { TimeInfo = DateTime.Now, RunTime = "1" });}List<RunTimeInfo> mdDataList = new List<RunTimeInfo>();private void btnQuary_Click_1(object sender, EventArgs e){using (EfContextRunInfo context = new EfContextRunInfo { CreateDateTime = DateTime.Now, IsSave = false, DynamicConnectionString = $"Data Source={Environment.CurrentDirectory}\\RunTime\\{DateTime.Now.ToString("yyyy-MM-dd")}.db" }){try{context.Database.EnsureCreated();var mdDatas = context.MdDatas.Where(md => md.Id>2);mdDataList = mdDataList.Union(mdDatas.ToList()).ToList();}catch (Microsoft.Data.Sqlite.SqliteException ex){//Debug.WriteLine(ex.Message);}catch (Exception ex){MessageBox.Show(ex.Message);}}}
}