如何用CodeSmith减少代码重复编写

上次简单介绍了下CodeSmith，今天做些详细介绍（转），希望可以对大家有帮助：

CodeSmith 是一种语法类似于asp.net的基于模板的代码生成器，程序可以自定义模板，从而减少重复编码的劳动量，提高效率。
安装CodeSmith 2.6注册后发现有两个可运行程序CodeSmith Studio.exe和CodeSmith Explorer.exe
CodeSmith Studio.exe用来创建自定义模板
CodeSmith Explorer.exe用来导入模板并且生成代码
打开 CodeSmith Studio.exe，新建一个C#模板。发现有如下类似与asp.net的标识符号
<% %>
<%= %>
<%@ %>
<script runat="template"> </script>
下面通过简单的例子说明如何用CodeSmith创建模板并生成代码
新建一个空的txt文件，在文件上部输入如下一个CodeTemplate指示,Language和TargetLanguage分别代表模板语言和创建代码语言，

<% @CodeTemplateLanguage = " C# " TargetLanguage = " C# " Description = " Generatesasimpleclass " %>

然后声明几个变量，用来为了能够在以后生成的代码嵌入，这里声明了三个名为NameSpace,ClassName,Contxt的变量。其他参数一目了然就不再说明了，

<% @PropertyName = " NameSpace " Type = " String "
Category = " Context "
Description = " Thenamespacetouseforthisclass " %>
<% @PropertyName = " ClassName " Type = " String "
Category = " Context "
Description = " Thenameoftheclasstogenerate " %>
<% @PropertyName = " DevelopersName " Type = " String "
Category = " Context "
Description = " Thenametoincludeinthecommentheader " %>

接下来建立将要生成代码的框架，在适当位置引用刚刚声明的变量名

using System;
namespace <%= NameSpace %>
{
/// <summary>
/// Summarydescriptionfor <%=ClassName%> .
/// </summary>
public class <%= ClassName %>
{
public <%= ClassName %> ()
{
}
}
}

最后，打开CodeSmith Explorer.exe，加载此模板,并且在属性对话框中任意更改声明的变量名，按Generate按钮生成合适的代码


以上简单的说明了CodeSmith的功能
下面看看在数据库访问中它是如何最小化我们的工作的
在这里我们要用到CodeSmith API中一个叫SchemaExplorer的组件，它提供了一系列类来操作数据库的框架,我们可以用它来创建表和存储过程，得到字段类型，字段名等。
如下是更新NorthWind数据库中orders表记录的存储过程,我们来看看如何自动生成它

CREATEPROCEDUREdbo.UpdateOrders
@OrderID int ,
@CustomerIDnchar( 5 ),
@EmployeeID int ,
@OrderDatedatetime,
@RequiredDatedatetime,
@ShippedDatedatetime,
@ShipVia int ,
@Freightmoney,
@ShipNamenvarchar( 40 ),
@ShipAddressnvarchar( 60 ),
@ShipCitynvarchar( 15 ),
@ShipRegionnvarchar( 15 ),
@ShipPostalCodenvarchar( 10 ),
@ShipCountrynvarchar( 15 )
AS

UPDATE[Orders]SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE

[OrderID] = @OrderID

第一步还是创建一个CodeTemplate指示，注意TargetLanguage属性改为了T-SQL，因为创建的SQL语言代码

<% @CodeTemplateLanguage = " C# " TargetLanguage = " T-SQL " Description = " Generatesaupdatestoredprocedure. " %>

然后加载SchemaExplorer组件，并导入SchemaExplorer命名空间，看这里是不是和asp.net很像

<% @AssemblyName = " SchemaExplorer " %>
<% @ImportNamespace = " SchemaExplorer " %>

接下来声明变量,因为要从数据库表中读取框架所以 Type 属性为SchemaExplorer.TableSchema

<% @Property Name = " SourceTable " Type = " SchemaExplorer.TableSchema " Category = " Context " Description = " Tablethatthestoredproceduresshouldbebasedon. " %>

下面就要写实际将要输出代码部分的模板了。
先写存储过程的第一行 ,<%%>内为引用前面声明变量名，代表表名

CREATEPROCEDUREdbo.Update <%= SourceTable.Name %>

第二步为存储过程创造将要声明的参数列表

// 开始循环遍历每列
<% for ( int i = 0 ;i < SourceTable.Columns.Count;i ++ ) { %>
// 传递每列给GetSqlParameterStatement函数
<%= GetSqlParameterStatement(SourceTable.Columns[i]) %>
// 循环结束条件
<% if (i < SourceTable.Columns.Count - 1 ) { %> , <% } %>
<% } % >
AS

定义GetSqlParameterStatement方法接受列参数返回参数名，和字段类型，注意函数要放在
<script runat="template"> </script>里

< scriptrunat = " template " >

public string GetSqlParameterStatement(ColumnSchemacolumn)

{
string param = " @ " + column.Name + " " + column.NativeType;
switch (column.DataType)
{
case DbType.Decimal:
{
param += " ( " + column.Precision + " , " + column.Scale + " ) " ;
break ;
}
default :
{
if (column.Size > 0 )
{
param += " ( " + column.Size + " ) " ;
}
break ;
}
}
return param;
}
</ script >

接下来创建存储过程的Update部分，语法类似不再说明

UPDATE[ <%= SourceTable.Name %> ]SET
<% for ( int i = 0 ;i < SourceTable.NonPrimaryKeyColumns.Count;i ++ ) { %>
[ <%= SourceTable.NonPrimaryKeyColumns[i].Name %> ] = @ <%= SourceTable.NonPrimaryKeyColumns[i].Name %><% if (i < SourceTable.NonPrimaryKeyColumns.Count - 1 ) { %> , <% } %>
<% } %>
// where条件，注意主键提取方法
WHERE
<% for ( int i = 0 ;i < SourceTable.PrimaryKey.MemberColumns.Count;i ++ ) { %>
<% if (i > 0 ) { %> AND <% } %>
[ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %> ] = @ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %>
<% } %>

最终为模板为如下形式

将其用CodeSmith Explorer.exe打开

可以任意选择数据库中的表,这里选择NorthWind中的0rders表

然后生成代码，就创建好了存储过程

CREATEPROCEDUREdbo.UpdateOrders
@OrderID int ,
@CustomerIDnchar( 5 ),
@EmployeeID int ,
@OrderDatedatetime,
@RequiredDatedatetime,
@ShippedDatedatetime,
@ShipVia int ,
@Freightmoney,
@ShipNamenvarchar( 40 ),
@ShipAddressnvarchar( 60 ),
@ShipCitynvarchar( 15 ),
@ShipRegionnvarchar( 15 ),
@ShipPostalCodenvarchar( 10 ),
@ShipCountrynvarchar( 15 )
AS

UPDATE[Orders]SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE

[OrderID] = @OrderID

同样，我们可以选择其他的表创建Updata存储过程，也可以自定义其他诸如insert delete等的存储过程，是不是很方便？^-^
以上只是CodeSmith的简单应用，还有其他的功能有待大家探索了。
关于CodeSmith社区一些模板资源，大家可以去如下地址选择下载
CodeSmith Peer Support Forum
Codesmith templates library

< scriptrunat = " template " >

public string GetSqlParameterStatement(ColumnSchemacolumn)

{
string param = " @ " + column.Name + " " + column.NativeType;
switch (column.DataType)
{
case DbType.Decimal:
{
param += " ( " + column.Precision + " , " + column.Scale + " ) " ;
break ;
}
default :
{
if (column.Size > 0 )
{
param += " ( " + column.Size + " ) " ;
}
break ;
}
}
return param;
}
</ script >

接下来创建存储过程的Update部分，语法类似不再说明

UPDATE[ <%= SourceTable.Name %> ]SET
<% for ( int i = 0 ;i < SourceTable.NonPrimaryKeyColumns.Count;i ++ ) { %>
[ <%= SourceTable.NonPrimaryKeyColumns[i].Name %> ] = @ <%= SourceTable.NonPrimaryKeyColumns[i].Name %><% if (i < SourceTable.NonPrimaryKeyColumns.Count - 1 ) { %> , <% } %>
<% } %>
// where条件，注意主键提取方法
WHERE
<% for ( int i = 0 ;i < SourceTable.PrimaryKey.MemberColumns.Count;i ++ ) { %>
<% if (i > 0 ) { %> AND <% } %>
[ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %> ] = @ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %>
<% } %>

最终为模板为如下形式

将其用CodeSmith Explorer.exe打开

可以任意选择数据库中的表,这里选择NorthWind中的0rders表

然后生成代码，就创建好了存储过程

CREATEPROCEDUREdbo.UpdateOrders
@OrderID int ,
@CustomerIDnchar( 5 ),
@EmployeeID int ,
@OrderDatedatetime,
@RequiredDatedatetime,
@ShippedDatedatetime,
@ShipVia int ,
@Freightmoney,
@ShipNamenvarchar( 40 ),
@ShipAddressnvarchar( 60 ),
@ShipCitynvarchar( 15 ),
@ShipRegionnvarchar( 15 ),
@ShipPostalCodenvarchar( 10 ),
@ShipCountrynvarchar( 15 )
AS

UPDATE[Orders]SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE

[OrderID] = @OrderID

同样，我们可以选择其他的表创建Updata存储过程，也可以自定义其他诸如insert delete等的存储过程，是不是很方便？^-^
以上只是CodeSmith的简单应用，还有其他的功能有待大家探索了。
关于CodeSmith社区一些模板资源，大家可以去如下地址选择下载
CodeSmith Peer Support Forum
Codesmith templates library

<% @CodeTemplateLanguage = " C# " TargetLanguage = " C# " Description = " Generatesasimpleclass " %>

然后声明几个变量，用来为了能够在以后生成的代码嵌入，这里声明了三个名为NameSpace,ClassName,Contxt的变量。其他参数一目了然就不再说明了，

<% @PropertyName = " NameSpace " Type = " String "
Category = " Context "
Description = " Thenamespacetouseforthisclass " %>
<% @PropertyName = " ClassName " Type = " String "
Category = " Context "
Description = " Thenameoftheclasstogenerate " %>
<% @PropertyName = " DevelopersName " Type = " String "
Category = " Context "
Description = " Thenametoincludeinthecommentheader " %>

接下来建立将要生成代码的框架，在适当位置引用刚刚声明的变量名

using System;
namespace <%= NameSpace %>
{
/// <summary>
/// Summarydescriptionfor <%=ClassName%> .
/// </summary>
public class <%= ClassName %>
{
public <%= ClassName %> ()
{
}
}
}

最后，打开CodeSmith Explorer.exe，加载此模板,并且在属性对话框中任意更改声明的变量名，按Generate按钮生成合适的代码


以上简单的说明了CodeSmith的功能
下面看看在数据库访问中它是如何最小化我们的工作的
在这里我们要用到CodeSmith API中一个叫SchemaExplorer的组件，它提供了一系列类来操作数据库的框架,我们可以用它来创建表和存储过程，得到字段类型，字段名等。
如下是更新NorthWind数据库中orders表记录的存储过程,我们来看看如何自动生成它

CREATEPROCEDUREdbo.UpdateOrders
@OrderID int ,
@CustomerIDnchar( 5 ),
@EmployeeID int ,
@OrderDatedatetime,
@RequiredDatedatetime,
@ShippedDatedatetime,
@ShipVia int ,
@Freightmoney,
@ShipNamenvarchar( 40 ),
@ShipAddressnvarchar( 60 ),
@ShipCitynvarchar( 15 ),
@ShipRegionnvarchar( 15 ),
@ShipPostalCodenvarchar( 10 ),
@ShipCountrynvarchar( 15 )
AS

UPDATE[Orders]SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE

[OrderID] = @OrderID

第一步还是创建一个CodeTemplate指示，注意TargetLanguage属性改为了T-SQL，因为创建的SQL语言代码

<% @CodeTemplateLanguage = " C# " TargetLanguage = " T-SQL " Description = " Generatesaupdatestoredprocedure. " %>

然后加载SchemaExplorer组件，并导入SchemaExplorer命名空间，看这里是不是和asp.net很像

<% @AssemblyName = " SchemaExplorer " %>
<% @ImportNamespace = " SchemaExplorer " %>

接下来声明变量,因为要从数据库表中读取框架所以 Type 属性为SchemaExplorer.TableSchema

<% @Property Name = " SourceTable " Type = " SchemaExplorer.TableSchema " Category = " Context " Description = " Tablethatthestoredproceduresshouldbebasedon. " %>

下面就要写实际将要输出代码部分的模板了。
先写存储过程的第一行 ,<%%>内为引用前面声明变量名，代表表名

CREATEPROCEDUREdbo.Update <%= SourceTable.Name %>

第二步为存储过程创造将要声明的参数列表

// 开始循环遍历每列
<% for ( int i = 0 ;i < SourceTable.Columns.Count;i ++ ) { %>
// 传递每列给GetSqlParameterStatement函数
<%= GetSqlParameterStatement(SourceTable.Columns[i]) %>
// 循环结束条件
<% if (i < SourceTable.Columns.Count - 1 ) { %> , <% } %>
<% } % >
AS

定义GetSqlParameterStatement方法接受列参数返回参数名，和字段类型，注意函数要放在
<script runat="template"> </script>里

< scriptrunat = " template " >

public string GetSqlParameterStatement(ColumnSchemacolumn)

{
string param = " @ " + column.Name + " " + column.NativeType;
switch (column.DataType)
{
case DbType.Decimal:
{
param += " ( " + column.Precision + " , " + column.Scale + " ) " ;
break ;
}
default :
{
if (column.Size > 0 )
{
param += " ( " + column.Size + " ) " ;
}
break ;
}
}
return param;
}
</ script >

接下来创建存储过程的Update部分，语法类似不再说明

UPDATE[ <%= SourceTable.Name %> ]SET
<% for ( int i = 0 ;i < SourceTable.NonPrimaryKeyColumns.Count;i ++ ) { %>
[ <%= SourceTable.NonPrimaryKeyColumns[i].Name %> ] = @ <%= SourceTable.NonPrimaryKeyColumns[i].Name %><% if (i < SourceTable.NonPrimaryKeyColumns.Count - 1 ) { %> , <% } %>
<% } %>
// where条件，注意主键提取方法
WHERE
<% for ( int i = 0 ;i < SourceTable.PrimaryKey.MemberColumns.Count;i ++ ) { %>
<% if (i > 0 ) { %> AND <% } %>
[ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %> ] = @ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %>
<% } %>

最终为模板为如下形式

将其用CodeSmith Explorer.exe打开

可以任意选择数据库中的表,这里选择NorthWind中的0rders表

然后生成代码，就创建好了存储过程

CREATEPROCEDUREdbo.UpdateOrders
@OrderID int ,
@CustomerIDnchar( 5 ),
@EmployeeID int ,
@OrderDatedatetime,
@RequiredDatedatetime,
@ShippedDatedatetime,
@ShipVia int ,
@Freightmoney,
@ShipNamenvarchar( 40 ),
@ShipAddressnvarchar( 60 ),
@ShipCitynvarchar( 15 ),
@ShipRegionnvarchar( 15 ),
@ShipPostalCodenvarchar( 10 ),
@ShipCountrynvarchar( 15 )
AS

UPDATE[Orders]SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE

[OrderID] = @OrderID

同样，我们可以选择其他的表创建Updata存储过程，也可以自定义其他诸如insert delete等的存储过程，是不是很方便？^-^
以上只是CodeSmith的简单应用，还有其他的功能有待大家探索了。
关于CodeSmith社区一些模板资源，大家可以去如下地址选择下载
CodeSmith Peer Support Forum
Codesmith templates library

< scriptrunat = " template " >

public string GetSqlParameterStatement(ColumnSchemacolumn)

{
string param = " @ " + column.Name + " " + column.NativeType;
switch (column.DataType)
{
case DbType.Decimal:
{
param += " ( " + column.Precision + " , " + column.Scale + " ) " ;
break ;
}
default :
{
if (column.Size > 0 )
{
param += " ( " + column.Size + " ) " ;
}
break ;
}
}
return param;
}
</ script >

接下来创建存储过程的Update部分，语法类似不再说明

UPDATE[ <%= SourceTable.Name %> ]SET
<% for ( int i = 0 ;i < SourceTable.NonPrimaryKeyColumns.Count;i ++ ) { %>
[ <%= SourceTable.NonPrimaryKeyColumns[i].Name %> ] = @ <%= SourceTable.NonPrimaryKeyColumns[i].Name %><% if (i < SourceTable.NonPrimaryKeyColumns.Count - 1 ) { %> , <% } %>
<% } %>
// where条件，注意主键提取方法
WHERE
<% for ( int i = 0 ;i < SourceTable.PrimaryKey.MemberColumns.Count;i ++ ) { %>
<% if (i > 0 ) { %> AND <% } %>
[ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %> ] = @ <%= SourceTable.PrimaryKey.MemberColumns[i].Name %>
<% } %>

最终为模板为如下形式

将其用CodeSmith Explorer.exe打开

可以任意选择数据库中的表,这里选择NorthWind中的0rders表

然后生成代码，就创建好了存储过程

CREATEPROCEDUREdbo.UpdateOrders
@OrderID int ,
@CustomerIDnchar( 5 ),
@EmployeeID int ,
@OrderDatedatetime,
@RequiredDatedatetime,
@ShippedDatedatetime,
@ShipVia int ,
@Freightmoney,
@ShipNamenvarchar( 40 ),
@ShipAddressnvarchar( 60 ),
@ShipCitynvarchar( 15 ),
@ShipRegionnvarchar( 15 ),
@ShipPostalCodenvarchar( 10 ),
@ShipCountrynvarchar( 15 )
AS

UPDATE[Orders]SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE

[OrderID] = @OrderID

同样，我们可以选择其他的表创建Updata存储过程，也可以自定义其他诸如insert delete等的存储过程，是不是很方便？^-^
以上只是CodeSmith的简单应用，还有其他的功能有待大家探索了。
关于CodeSmith社区一些模板资源，大家可以去如下地址选择下载
CodeSmith Peer Support Forum
Codesmith templates library