.net使用自定义类属性实例

[AttributeUsage(AttributeTargets.Class, Inherited = false, AllowMultiple = false)]
public sealed class TableAttribute : Attribute
{
        private readonly string _TableName = "";
        public TableAttribute(string tableName)
        {
            this._TableName = tableName;
        }
        public string TableName
        {
            get { return this._TableName; }
        }
}

[AttributeUsage(AttributeTargets.Property, Inherited = false, AllowMultiple = false)]
public class FieldAttribute : Attribute
{
        private readonly string _FieldName = "";    ///数据库的字段名称
        private System.Data.DbType _Type = System.Data.DbType.String;   ///数据库的字段类型
 
        public FieldAttribute(string fieldName)
       {
              this._FieldName=fieldName;
       }
 
        public FieldAttribute(string fieldName,System.Data.DbType type)
       {
              this._FieldName=fieldName;
              this._Type=type;
       }
 
       public string FieldName
        {
            get { return this._FieldName; }
        }
 
        public System.Data.DbType Type
        {
             get{return this._Type;}
        }
}

public class BaseEntity
{
        public BaseEntity()
        {
        }
 
         /// <summary>
        /// 获取表名称
        /// </summary>
        /// <returns></returns>
        public string GetTableName()
        {
            Type type = this.GetType();
            object[] objs = type.GetCustomAttributes(typeof(TableAttribute), true);
            if (objs.Length <= 0)
            {
                throw new Exception("实体类没有标识TableAttribute属性");
            }
            else
            {
                object obj = objs[0];
                TableAttribute ta = (TableAttribute)obj;
                return ta.TableName;                            //获取表名称
            }
        }
        /// <summary>
        /// 获取数据实体类上的FieldAttribute
        /// </summary>
        /// <param name="propertyName"></param>
        /// <returns></returns>
        public FieldAttribute GetFieldAttribute(string propertyName)
        {
            PropertyInfo field = this.GetType().GetProperty(propertyName);
            if (field == null)
            {
                throw new Exception("属性名" + propertyName + "不存在");
            }
            object[] objs = field.GetCustomAttributes(typeof(FieldAttribute), true);
            if (objs.Length <= 0)
            {
                throw new Exception("类体属性名" + propertyName + "没有标识FieldAttribute属性");
            }
            else
            {
                object obj = objs[0];
                FieldAttribute fieldAttribute=(FieldAttribute)obj;
                fieldAttribute.FieldValue=field.GetValue(this,null);
                return fieldAttribute;
            }
        }
}

[Table("Wincms_Dictionary")]            ///映射到数据库的Wincms_Dictionary表
public class Wincms_Dictionary : BaseEntity
{
         private int _DictionaryId;
 
         public Wincms_Dictionary()
         {
         }
 
        [Field("DictionaryId",DbType.Int32)]                ///映射到数据库的Wincms_Dictionary表中的字段
        public int DictionaryId
        {
            get { return this._DictionaryId; }
            set
            {
                this._DictionaryId = value;
            }
        }
}
 
///基于实体类获取实体对应的表名称和字段名称
public class Test
{
 
       public static void main(string[] args)
        {
               Wincms_Dictionary dict=new Wincms_Dictionary();
               Console.WriteLine("表名称："+GetTableName(dict));
               Console.WriteLine("字段名称:"+GetFieldName(dict,"DictionaryId"));
               Console.Read();
        }
 
       ///获取实体表名称
       public  static string GetTableName(BaseEntity entity)
       {
                return entity.GetTableName();
       }
 
       ///获取实体字段名称
       public static string GetFieldName(BaseEntity entity,string propertyName)
       {
              FieldAttribute fieldAttribute=entity.GetFieldAttribute(propertyName);
              return fieldAttribute.FieldName;
       }
}

表名称：Wincms_Dictionary
字段名称：DictionaryId