.net core自定义特性操作

最近移植之前写的几个类，发现特性操作发生了一些改变。

直接看代码，建立表和字段特性类，添加一个用户表，设置好特性。

 using System;
 
 namespace TestDemo
 {
     /// <summary>
     /// 表实体特性
     /// </summary>
     [AttributeUsage(AttributeTargets.Class, Inherited = false)]
     public class TableAttribute : Attribute
     {
         /// <summary>
         /// 数据库表名称
         /// </summary>
         public string TableName { get; set; }
         /// <summary>
         /// 数据库表注释
         /// </summary>
         public string Description { get; set; }
 
         public TableAttribute()
         {
             TableName = string.Empty;
             Description = string.Empty;
         }
     }
 }

表特性

 using System;
 
 namespace TestDemo
 {
     /// <summary>
     /// 列特性
     /// </summary>
     [AttributeUsage( AttributeTargets.Property , AllowMultiple = false)]
     public class TableColumnAttribute : Attribute
     {
         /// <summary>
         /// 列名称
         /// </summary>
         public string ColumnName { get; set; }
         /// <summary>
         /// 字段说明
         /// </summary>
         public string Description { get; set; }
         /// <summary>
         /// 是否是主键
         /// </summary>
         public bool IsPrimaryKey { get; set; }
         /// <summary>
         /// 主键是否自动增长
         /// </summary>
         public bool IsPrimaryKeyAuto { get; set; }
         /// <summary>
         /// 数据库数据类型
         /// </summary>
         public string DbDataType { get; set; }
         /// <summary>
         /// 字符串最大长度
         /// </summary>
         public int MaxLength { get; set; }
         /// <summary>
         /// 是否不可为空
         /// </summary>
         public bool NotNull { get; set; }
 
         public TableColumnAttribute()
         {
             ColumnName = string.Empty;
             Description = string.Empty;
             IsPrimaryKey = false;
             IsPrimaryKeyAuto = false;
             DbDataType = "varchar";
             MaxLength = ;
             NotNull = false;
         }
     }
 }

表字段特性

 namespace TestDemo
 {
     [Table(Description = "用户表", TableName = "USER")]
     public class User
     {
         [TableColumn(ColumnName = "ID", DbDataType = "int", Description = "主键", IsPrimaryKey = true, IsPrimaryKeyAuto = true, MaxLength = , NotNull = true)]
         public int Id { get; set; }
 
         [TableColumn(ColumnName = "LOGINNO", DbDataType = "varchar", Description = "登录名", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = , NotNull = true)]
         public string LoginNo { get; set; }
 
         [TableColumn(ColumnName = "USERNAME", DbDataType = "varchar", Description = "用户姓名", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = , NotNull = false)]
         public string UserName { get; set; }
 
         [TableColumn(ColumnName = "NICKNAME", DbDataType = "varchar", Description = "昵称", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = , NotNull = false)]
         public string NickName { get; set; }
 
         [TableColumn(ColumnName = "TEL", DbDataType = "varchar", Description = "电话", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = , NotNull = false)]
         public string Tel { get; set; }
     }
 }

用户表

获取用户表以及表字段的特性。

 using System;
 using System.Reflection;
 using System.Text;
 
 namespace TestDemo
 {
     public class Program
     {
         public static void Main(string[] args)
         {
             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
 
             TableAttribute table = GetTableAttribute<User>();
             Console.WriteLine("User(TableName:" + table.TableName + "\r\n,Description:" + table.Description + ")");
             Console.WriteLine();
 
             TableColumnAttribute colId = GetTableColumnAttribute<User>("Id");
             Console.WriteLine("Id(ColumnName:" + colId.ColumnName
                 + "\r\n,DbDataType:" + colId.DbDataType
                 + "\r\n,Description:" + colId.Description
                 + "\r\n,IsPrimaryKey:" + colId.IsPrimaryKey
                 + "\r\n,IsPrimaryKeyAuto:" + colId.IsPrimaryKeyAuto
                 + "\r\n,MaxLength:" + colId.MaxLength
                 + "\r\n,NotNull:" + colId.NotNull + ")");
             Console.WriteLine();
 
             TableColumnAttribute colName = GetTableColumnAttribute<User>("UserName");
             Console.WriteLine("UserName(ColumnName:" + colName.ColumnName
                 + "\r\n,DbDataType:" + colName.DbDataType
                 + "\r\n,Description:" + colName.Description
                 + "\r\n,IsPrimaryKey:" + colName.IsPrimaryKey
                 + "\r\n,IsPrimaryKeyAuto:" + colName.IsPrimaryKeyAuto
                 + "\r\n,MaxLength:" + colName.MaxLength
                 + "\r\n,NotNull:" + colName.NotNull + ")");
 
             Console.ReadLine();
         }
 
         /// <summary>
         /// 获取表特性
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <returns></returns>
         public static TableAttribute GetTableAttribute<T>()
         {
             Type t = typeof(T);
             TableAttribute m = t.GetTypeInfo().GetCustomAttribute<TableAttribute>();
             return m;
         }
 
         /// <summary>
         /// 获取列特性
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <param name="propertyName"></param>
         /// <returns></returns>
         public static TableColumnAttribute GetTableColumnAttribute<T>(string propertyName)
         {
             TableColumnAttribute m = null;
 
             Type t = typeof(T);
             PropertyInfo[] arryProperty = t.GetProperties();
             if (arryProperty != null)
             {
                 foreach (PropertyInfo p in arryProperty)
                 {
                     if (p.Name == propertyName)
                     {
                         m = p.GetCustomAttribute<TableColumnAttribute>();
                     }
                 }
             }
 
             return m;
         }
     }
 }

Program

运行起来看看获取的情况！