.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。

 1 using System;
 2 
 3 namespace TestDemo
 4 {
 5     /// 

 6     /// 表实体特性
 7     /// 
 8     [AttributeUsage(AttributeTargets.Class, Inherited = false)]
 9     public class TableAttribute : Attribute
10     {        
11         /// 

12         /// 数据库表名称
13         /// 
14         public string TableName { get; set; }
15         /// 

16         /// 数据库表注释
17         /// 
18         public string Description { get; set; }
19 
20         public TableAttribute()
21         {
22             TableName = string.Empty;
23             Description = string.Empty;
24         }
25     }
26 }

表特性

 1 using System;
 2 
 3 namespace TestDemo
 4 {
 5     /// 

 6     /// 列特性
 7     /// 
 8     [AttributeUsage( AttributeTargets.Property , AllowMultiple = false)]
 9     public class TableColumnAttribute : Attribute
10     {
11         /// 

12         /// 列名称
13         /// 
14         public string ColumnName { get; set; }
15         /// 

16         /// 字段说明
17         /// 
18         public string Description { get; set; }
19         /// 

20         /// 是否是主键
21         /// 
22         public bool IsPrimaryKey { get; set; }
23         /// 

24         /// 主键是否自动增长
25         /// 
26         public bool IsPrimaryKeyAuto { get; set; }
27         /// 

28         /// 数据库数据类型
29         /// 
30         public string DbDataType { get; set; }
31         /// 

32         /// 字符串最大长度
33         /// 
34         public int MaxLength { get; set; }
35         /// 

36         /// 是否不可为空
37         /// 
38         public bool NotNull { get; set; }
39 
40         public TableColumnAttribute()
41         {
42             ColumnName = string.Empty;
43             Description = string.Empty;
44             IsPrimaryKey = false;
45             IsPrimaryKeyAuto = false;
46             DbDataType = "varchar";
47             MaxLength = 50;
48             NotNull = false;
49         }
50     }
51 }

表字段特性

 1 namespace TestDemo
 2 {
 3     [Table(Description = "用户表", TableName = "USER")]
 4     public class User
 5     {
 6         [TableColumn(ColumnName = "ID", DbDataType = "int", Description = "主键", IsPrimaryKey = true, IsPrimaryKeyAuto = true, MaxLength = 0, NotNull = true)]
 7         public int Id { get; set; }
 8 
 9         [TableColumn(ColumnName = "LOGINNO", DbDataType = "varchar", Description = "登录名", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = 20, NotNull = true)]
10         public string LoginNo { get; set; }
11 
12         [TableColumn(ColumnName = "USERNAME", DbDataType = "varchar", Description = "用户姓名", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = 20, NotNull = false)]
13         public string UserName { get; set; }
14 
15         [TableColumn(ColumnName = "NICKNAME", DbDataType = "varchar", Description = "昵称", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = 30, NotNull = false)]
16         public string NickName { get; set; }
17 
18         [TableColumn(ColumnName = "TEL", DbDataType = "varchar", Description = "电话", IsPrimaryKey = false, IsPrimaryKeyAuto = false, MaxLength = 11, NotNull = false)]
19         public string Tel { get; set; }
20     }
21 }

用户表

    获取用户表以及表字段的特性。

 1 using System;
 2 using System.Reflection;
 3 using System.Text;
 4 
 5 namespace TestDemo
 6 {
 7     public class Program
 8     {
 9         public static void Main(string[] args)
10         {
11             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
12 
13             TableAttribute table = GetTableAttribute();
14             Console.WriteLine("User(TableName:" + table.TableName + "\r\n,Description:" + table.Description + ")");
15             Console.WriteLine();
16 
17             TableColumnAttribute colId = GetTableColumnAttribute("Id");
18             Console.WriteLine("Id(ColumnName:" + colId.ColumnName 
19                 + "\r\n,DbDataType:" + colId.DbDataType
20                 + "\r\n,Description:" + colId.Description
21                 + "\r\n,IsPrimaryKey:" + colId.IsPrimaryKey
22                 + "\r\n,IsPrimaryKeyAuto:" + colId.IsPrimaryKeyAuto
23                 + "\r\n,MaxLength:" + colId.MaxLength
24                 + "\r\n,NotNull:" + colId.NotNull + ")");
25             Console.WriteLine();
26 
27             TableColumnAttribute colName = GetTableColumnAttribute("UserName");
28             Console.WriteLine("UserName(ColumnName:" + colName.ColumnName
29                 + "\r\n,DbDataType:" + colName.DbDataType
30                 + "\r\n,Description:" + colName.Description
31                 + "\r\n,IsPrimaryKey:" + colName.IsPrimaryKey
32                 + "\r\n,IsPrimaryKeyAuto:" + colName.IsPrimaryKeyAuto
33                 + "\r\n,MaxLength:" + colName.MaxLength
34                 + "\r\n,NotNull:" + colName.NotNull + ")");
35 
36             Console.ReadLine();
37         }
38 
39         /// 

40         /// 获取表特性
41         /// 
42         /// 
43         /// 
44         public static TableAttribute GetTableAttribute()
45         {
46             Type t = typeof(T);
47             TableAttribute m = t.GetTypeInfo().GetCustomAttribute();
48             return m;
49         }
50 
51         /// 

52         /// 获取列特性
53         /// 
54         /// 
55         /// 
56         /// 
57         public static TableColumnAttribute GetTableColumnAttribute(string propertyName)
58         {
59             TableColumnAttribute m = null;
60 
61             Type t = typeof(T);
62             PropertyInfo[] arryProperty = t.GetProperties();
63             if (arryProperty != null)
64             {
65                 foreach (PropertyInfo p in arryProperty)
66                 {            
67                     if (p.Name == propertyName)
68                     {
69                         m = p.GetCustomAttribute();
70                     }
71                 }
72             }
73             
74             return m;
75         }
76     }
77 }

Program

    运行起来看看获取的情况！

转载于:https://www.cnblogs.com/moncci/p/6347144.html