1.自定義 表名屬性 TableNameAttribute
2.自定義 主鍵屬性 PrimaryKeyAttribute
3.自定義 列名屬性 TableColumnAttribute
4.數據表person對應的實體類person.cs
5.獲得person.cs類型實體 對應的表名及字段名

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下面的屬性代碼文件 都直接建立在App_Code下 以方便使用

1.自定義 表名屬性 TableNameAttribute
------------------------------------

using?System;

/**////?<summary>
///?TableNameAttribute?的摘要說明
///?</summary>

[AttributeUsage(?AttributeTargets.Class,?AllowMultiple=false,?Inherited=true?)]
public?sealed?class?TableNameAttribute?:?Attribute
{
????private?string?name;
????private?string?schema;
????//private?CacheStrategy?cacheStrategy?=?GentleSettings.DefaultCacheStrategy;

????/**////?<summary>
????///?The?constructor?for?the?TableName?attribute.
????///?</summary>
????///?<param?name="name">The?name?of?the?database?table?used?to?store?instances?of?this?class.</param>
????public?TableNameAttribute(?string?name?)
????{
????????this.name?=?name;
????}

????/**////?<summary>
????///?The?constructor?for?the?TableName?attribute.
????///?</summary>
????///?<param?name="name">The?name?of?the?database?table?used?to?store?instances?of?this?class.</param>
????///?<param?name="strategy">The?cache?stratgey?to?use?for?instances?of?this?type.?<see?
????///?cref="CacheStrategy"/>?for?a?list?of?available?options.</param>
????//public?TableNameAttribute(?string?name,?CacheStrategy?strategy?)
????//{
????//????this.name?=?name;
????//????this.cacheStrategy?=?strategy;
????//}

????/**////?<summary>
????///?The?name?of?the?database?table?used?to?store?instances?of?this?class.
????///?</summary>
????public?string?Name
????{
????????get?{?return?name;?}
????}

????/**////?<summary>
????///?The?optional?schema?name?with?which?to?prefix?the?table?name?in?queries.
????///?This?value?overrides?the?default?schema?definition?(if?present)?in?the
????///?configuration?file.?Note:?this?property?is?currently?unused.?
????///?</summary>
????public?string?Schema
????{
????????get?{?return?schema;?}
????????set?{?schema?=?value;?}
????}

????/**//////?<summary>
????/////?The?cache?behavior?for?objects?of?this?type.?<see?cref="CacheStrategy"/>?
????/////?for?a?list?of?available?options.
????/////?</summary>
????//public?CacheStrategy?CacheStrategy
????//{
????//????get?{?return?cacheStrategy;?}
????//????set?{?cacheStrategy?=?value;?}
????//}
}

2.自定義 主鍵屬性 PrimaryKeyAttribute
------------------------------------
using?System;

/**////?<summary>
///?PrimaryKeyAttribute?的摘要說明
///?</summary>
[AttributeUsage(AttributeTargets.Property?|?AttributeTargets.Field,?AllowMultiple?=?true,?Inherited?=?true)]
public?sealed?class?PrimaryKeyAttribute?:?Attribute
{
????private?bool?autoGenerated?=?false;

????/**////?<summary>
????///?Set?this?property?to?true?for?primary?keys?that?are?automatically?assigned
????///?by?the?database?on?insert?(identity?columns?in?SQL?server?terminology).?
????///?</summary>
????public?bool?AutoGenerated
????{
????????get?{?return?autoGenerated;?}
????????set?{?autoGenerated?=?value;?}
????}
}

3.自定義 列名屬性 TableColumnAttribute
--------------------------------------
using?System;
using?System.Data;

/**////?<summary>
///?TableColumnAttribute?的摘要說明
///?</summary>
[AttributeUsage(?AttributeTargets.Property?|?AttributeTargets.Field,?AllowMultiple=false,?Inherited=true?)]
public?class?TableColumnAttribute?:?Attribute
{
????private?string?name;
????private?bool?notNull;
????private?int?size;
????private?bool?hasDbType?=?false;?//?true?when?DbType?property?has?been?set
????private?long?dbType;
????private?object?nullValue?=?null;
????private?bool?handleEnumAsString?=?false;
????private?bool?isReadOnly?=?false;
????private?bool?isUpdateAfterWrite?=?false;

????/**////?<summary>
????///?Constructor?for?table?columns?that?are?named?after?their?property?counterpart
????///?and?whose?value?cannot?be?null.
????///?</summary>
????public?TableColumnAttribute()
????????:?this(null,?true)
????{
????}

????/**////?<summary>
????///?Constructor?for?table?columns?that?are?named?after?their?property?counterpart.
????///?</summary>
????///?<param?name="notNull">A?boolean?telling?whether?null?values?are?allowed?in?the?database</param>
????public?TableColumnAttribute(bool?notNull)
????????:?this(null,?notNull)
????{
????}

????/**////?<summary>
????///?Constructor?for?table?columns?whose?value?cannot?be?null.
????///?</summary>
????///?<param?name="name">The?name?of?the?database?column</param>
????public?TableColumnAttribute(string?name)
????????:?this(name,?true)
????{
????}

????/**////?<summary>
????///?Constructor?for?table?columns.
????///?</summary>
????///?<param?name="name">The?name?of?the?database?column</param>
????///?<param?name="notNull">A?boolean?telling?whether?null?values?are?allowed?in?the?database</param>
????public?TableColumnAttribute(string?name,?bool?notNull)
????{
????????this.name?=?name;
????????this.notNull?=?notNull;
????}

????/**////?<summary>
????///?The?name?of?the?database?column?for?storing?the?property?decorated?with?this?attribute.
????///?</summary>
????public?string?Name
????{
????????get?{?return?name;?}
????}

????/**////?<summary>
????///?This?property?(defaults?to?true)?can?be?used?to?specify?whether?NULL?values?are
????///?allowed?in?the?database.?This?allows?the?framework?to?fail?early?if?a?constraint
????///?is?violated.
????///?</summary>
????public?bool?NotNull
????{
????????get?{?return?notNull;?}
????????set?{?notNull?=?value;?}
????}

????/**////?<summary>
????///?The?database?type?of?the?field?in?the?database.?Beware?that?the?DbType?enumeration
????///?values?are?NOT?the?ones?used?by?the?individual?providers.?Gentle?does?NOT?convert
????///?the?DbType?to?a?"best?match"?for?the?provider.?It?is?therefore?recommended?that?
????///?you?use?the?DatabaseType?below?until?a?better?type?definition?system?is?available.
????///?</summary>
????[Obsolete("Please?use?DatabaseType?instead.")]
????public?DbType?DbType
????{
????????get?{?return?(DbType)dbType;?}
????????set
????????{
????????????hasDbType?=?true;
????????????dbType?=?(long)value;
????????}
????}

????/**////?<summary>
????///?The?database?type?of?the?field?in?the?database.?Convert?the?actual?database?type
????///?enumeration?to?a?long?by?casting?it?in?the?declaration.
????///?</summary>
????public?long?DatabaseType
????{
????????get?{?return?dbType;?}
????????set
????????{
????????????hasDbType?=?true;
????????????dbType?=?value;
????????}
????}

????/**////?<summary>
????///?The?size?or?length?of?the?field?in?the?database.?String?properties?will?be?clipped
????///?to?fit.
????///?This?feature?will?obsoleted?once?Gentle?is?capable?of?extracting?type?and?size?
????///?information?directly?from?the?database.?If?specified,?the?values?must?match
????///?those?extracted?from?the?database?(when?implemented).
????///?</summary>
????public?int?Size
????{
????????get?{?return?size;?}
????????set?{?size?=?value;?}
????}

????/**////?<summary>
????///?This?property?indicates?whether?a?DbType?was?specified.?This?construct?is?necessary
????///?because?the?DbType?enum?has?no?value?for?undefined.
????///?</summary>
????public?bool?HasDbType
????{
????????get?{?return?hasDbType;?}
????}

????/**////?<summary>
????///?Obsolete,?use?NullValue?instead.
????///?</summary>
????[Obsolete("Use?NullValue?instead.")]
????public?object?MagicValue
????{
????????get?{?return?nullValue;?}
????????set?{?nullValue?=?value;?}
????}

????/**////?<summary>
????///?This?value?of?this?property?is?used?when?a?column?is?NotNull?and?the?property?value
????///?is?null.??If?this?is?undefined?the?framework?will?throw?an?error?for?NotNull?columns
????///?whose?values?are?null.
????///?</summary>
????public?object?NullValue
????{
????????get?{?return?nullValue;?}
????????set?{?nullValue?=?value;?}
????}

????NullValue?Helper?Properties?for?VB.NET?Users#region?NullValue?Helper?Properties?for?VB.NET?Users
????/**////?<summary>
????///?This?property?allows?type-safe?setting?of?the?NullValue?for?VB?users.
????///?</summary>
????public?int?NullValue_int
????{
????????set?{?NullValue?=?value;?}
????}
????/**////?<summary>
????///?This?property?allows?type-safe?setting?of?the?NullValue?for?VB?users.
????///?</summary>
????public?NullOption?NullValue_opt
????{
????????set?{?NullValue?=?value;?}
????}
????#endregion

????/**////?<summary>
????///?This?value?indicates?that?the?column?should?not?be?set?on?insert?and?update.?It?is
????///?primarily?useful?for?columns?that?are?set?internally?by?the?database.
????///?</summary>
????public?bool?IsReadOnly
????{
????????get?{?return?isReadOnly;?}
????????set?{?isReadOnly?=?value;?}
????}

????/**////?<summary>
????///?This?value?indicates?that?the?column?must?be?read?after?each?insert?and?update.?It?is
????///?primarily?useful?for?columns?that?are?set?internally?by?the?database.?Note?that?using
????///?this?feature?(by?setting?this?to?true?for?any?column)?will?significantly?impact?
????///?performance?for?the?worse,?as?for?every?update/insert?another?select?will?be?
????///?performed.?Also,?fields?will?be?updated?using?reflection?after?select,?which?is?also
????///?quite?slow?(depending?on?the?number?of?columns).
????///?</summary>
????public?bool?IsUpdateAfterWrite
????{
????????get?{?return?isUpdateAfterWrite;?}
????????set?{?isUpdateAfterWrite?=?value;?}
????}

????/**////?<summary>
????///?If?member?which?has?this?attribute?attached?is?enum?then?this?property
????///?indicates?wheter?framework?saves?it?as?string?or?as?integer.
????///?Default?is?false,?ie?enums?are?saved?as?integers
????///?</summary>
????public?bool?HandleEnumAsString
????{
????????get?{?return?handleEnumAsString;?}
????????set?{?handleEnumAsString?=?value;?}
????}
}

public?enum?NullOption
{
????/**////?<summary>
????///?&lt;type&gt;.MinValue?will?be?stored?as?NULL,?and?NULL?will?be?read?as?&lt;type&gt;.MinValue.
????///?</summary>
????MinValue,
????/**////?<summary>
????///?&lt;type&gt;.MaxValue?will?be?stored?as?NULL,?and?NULL?will?be?read?as?&lt;type&gt;.MaxValue.
????///?</summary>
????MaxValue,
????/**////?<summary>
????///?0?(or?the?equivalent?for?other?numeric?types)?will?be?stored?as?NULL,?and?NULL?will?be?read?as?0.
????///?</summary>?This?value?can?only?be?used?with?numeric?types?(such?as?decimal).
????Zero,
????/**////?<summary>
????///?Guid.Empty?will?be?stored?as?NULL,?and?NULL?will?be?read?as?Guid.Empty.?This?value?can?only?be
????///?used?with?Guid?fields.
????///?</summary>
????EmptyGuid
}
4.數據表person對應的實體類person.cs
------------------------------------
using?System;
using?System.Data;
using?System.Configuration;
using?System.Web;
using?System.Web.Security;
using?System.Web.UI;
using?System.Web.UI.WebControls;
using?System.Web.UI.WebControls.WebParts;
using?System.Web.UI.HtmlControls;

/**////?<summary>
///?person?的摘要說明
///?</summary>

[TableName("person")]
public?class?person
{
????public?person()
????{
????}

????//[TableColumn("personID",?NotNull?=?true),?PrimaryKey]
????protected?int?_personID;
????//[TableColumn("personName",?NotNull?=?true)]
????protected?string?_personName?=?String.Empty;

????[TableColumn("personID",?NotNull?=?true),?PrimaryKey]
????public?int?PersonID
????{
????????get?{?return?_personID;?}
????????set?{?_personID?=?value;?}
????}

????[TableColumn("personName",?NotNull?=?true)]
????public?string?PersonName
????{
????????get?{?return?_personName;?}
????????set?{?_personName?=?value;?}
????}
}

5.獲得person.cs類型實體 對應的表名及字段名
------------------------------------------
protected?void?Button1_Click(object?sender,?EventArgs?e)
{
????person?aPerson?=?new?person();
????aPerson.PersonID?=?22;
????aPerson.PersonName?=?"zhangsan";

????Type?aType?=?aPerson.GetType();

????//類實體公開屬性對應的列名屬性
????PropertyInfo[]?aPropertyInfos?=?aType.GetProperties();
????string?strPublicProperty?=?"?";
????for?(int?i?=?0;?i?<?aPropertyInfos.Length;?i++)
????{
????????PropertyInfo?aPropertyInfo?=?(PropertyInfo)aPropertyInfos[i];
????????strPublicProperty?+=?i.ToString()?+?"?:?實體屬性名?"?+?aPropertyInfo.Name;
????????strPublicProperty?+=?"?對應值?"?+?aPropertyInfo.GetValue(aPerson,?null).ToString()?+?"?";
????????object[]?attrs?=?aPropertyInfo.GetCustomAttributes(typeof(TableColumnAttribute),?true);
????????for?(int?m?=?0;?m?<?attrs.Length;?m++)
????????{
????????????strPublicProperty?+=?"?對應列名?"?+?((TableColumnAttribute)attrs[m]).Name;
????????}
????}
????this.TextBox1.Text?=?strPublicProperty;


????//FieldInfo[]?aFieldInfos?=?aType.GetFields();
????//string?strPublicField?=?"?";
????//for?(int?j?=?0;?j?<?aFieldInfos.Length;?j++)
????//{
????//????FieldInfo?aFieldInfo?=?(FieldInfo)aFieldInfos[j];
????//????strPublicField?+=?j.ToString()?+?"?:?"?+?aFieldInfo.Name?+?"?";
????//}
????//this.TextBox2.Text?=?strPublicField;
????

????//類實體對應的表名屬性
????string?strTablePKName?=?"?";
????object[]?attrsAA?=?aType.GetCustomAttributes(typeof(TableNameAttribute),?true);
????for?(int?n?=?0;?n?<?attrsAA.Length;?n++)
????{
????????strTablePKName?+=?"?"?+?((TableNameAttribute)attrsAA[n]).Name;
????}

????//類實體對應的主鍵屬性
????MemberInfo[]?aMemberInfos?=?aType.GetMembers(BindingFlags.Public?|?BindingFlags.NonPublic?|?BindingFlags.Instance);
????string?strMemberInfo?=?"?";
????for?(int?k?=?0;?k?<?aMemberInfos.Length;?k++)
????{
????????MemberInfo?aM?=?aMemberInfos[k];
????????object[]?attrs?=?aM.GetCustomAttributes(typeof(PrimaryKeyAttribute),?true);
????????for?(int?m?=?0;?m?<?attrs.Length;?m++)
????????{
????????????strTablePKName?+=?"?主鍵?"?+?aM.Name;
????????}
????}

????this.TextBox2.Text?=?strTablePKName;
???
}

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