说起.NET的配置文件,.NET的开发人员无人不知,无人不用,如下面的配置节点,基本上每个.NET开发的项目都会出现像下面的配置,出现在App.config或者Web.config中
<connectionStrings>
<add name=
"
DbConnectionString
"
connectionString=
"
....
"
/>
</connectionStrings>
<appSettings>
<add key=
"
LogFilePath
"
value=
"
c:/Logs/
"
/>
</appSettings>
一般的项目用NET提供的配置节点就已经够用了,但是如果项目的配置文件很多很多,appSettings就会出现大量的配置,基本上都是key和value的组合,如果再加上命名不易读,维护就会很麻烦,又或者你自己写了一个框架给别人用,需要定义符合自己的配置节点,所以有些时候我们需要自定义一些配置.
其实NET已经提供了自定义配置的基类和一些接口,对创建自定义的配置已经非常方便了,下面就开始做几个简单的实例吧
1. 创建一个控制台的项目 CustomConfigurationDemo，添加App.Config并且引用System.configuration dll
2. 创建 CustomConfigurationFirst类继承ConfigurationSection，添加属性long Id， string Name，string FirstProperty，并且通过ConfigurationPropertyAttribute标记属性，第一个字符串为 配置文件中配置的属性名，DefaultValue为默认值，其他属性就不一一介绍了，可以参考ConfigurationPropertyAttribute的注释信息。
public
class
CustomConfigurationFirst : ConfigurationSection
{
private
static
CustomConfigurationFirst setting;
public
static
CustomConfigurationFirst Setting
{
get
{
if
(setting ==
null
)
setting
= (CustomConfigurationFirst)ConfigurationManager.GetSection(
"
firstCustomConfiguration
"
);
return
setting;
}
}
[ConfigurationProperty(
"
id
"
, DefaultValue =
"
1
"
, IsRequired =
true
)]
public
long
Id
{
get
{
return
(
long
)
this
[
"
id
"
]; }
set
{
this
[
"
id
"
] =
value; }
}
[ConfigurationProperty(
"
name
"
, DefaultValue =
"
Lily
"
, IsRequired =
true
)]
public
string
Name
{
get
{
return
(
string
)
this
[
"
name
"
]; }
set
{
this
[
"
name
"
] =
value; }
}
[ConfigurationProperty(
"
firstProperty
"
, DefaultValue =
"
Property1
"
, IsRequired =
true
)]
public
string
FirstProperty
{
get
{
return
(
string
)
this
[
"
firstProperty
"
]; }
set
{
this
[
"
firstProperty
"
] =
value; }
}
}
我们自定义的配置创建好了，现在需要添加配置到App.config文件中，如下图所示，首先需要创建configSections，把自定义的节点加进去，name随便填写（填写的值将会与代码中的ConfigurationManager.GetSection("firstCustomConfiguration")名称对应），type需要填写自定义配置节点类的全名称和程序集
<?xml version=
"
1.0
"
encoding=
"
utf-8
"
?>
<configuration>
<configSections>
<section name=
"
firstCustomConfiguration
"
type=
"
CustomConfigurationDemo.CustomConfigurationFirst,CustomConfigurationDemo
"
/>
</configSections>
<firstCustomConfiguration id=
"
12
"
name=
"
name
"
firstProperty=
"
property2
"
/>
</configuration>
一切准备就绪，用控制台程序打印出我们刚刚配置的属性看看吧！
Console.WriteLine("----CustomConfigurationFirst---------------------");
CustomConfigurationFirst settingFirst = CustomConfigurationFirst.Setting;
Console.WriteLine("settingFirst.Id:" + settingFirst.Id);
Console.WriteLine("settingFirst.Name:" + settingFirst.Name);
Console.WriteLine("settingFirst.FirstProperty"+ settingFirst.FirstProperty);
Console.WriteLine("--------------------------------------------------");
运行结果如下，和我们配置文件中设置的值一样，是不是感觉很简单。
3. 有时候我们需要在配置文件中加一些子节点，应该怎么做呢？
先创建一个 UrlConfigurationElement：ConfigurationElement，在ConfigurationElement里面添加属性和在Section里面添加是一样的，然后我们创建一个CustomConfigurationSecond : ConfigurationSection，并创建一个属性的类型是UrlConfigurationElement的，如下图所示：
[ConfigurationProperty(
"
url
"
)]
public
UrlConfigurationElement UrlElement
{
get
{
return
(UrlConfigurationElement)
this
[
"
url
"
]; }
set
{
this
[
"
url
"
] =
value; }
}
此时配置文件添加的配置为：
<secondCustomConfiguration>
<url name=
"
baidu
"
url=
"
http://www.baidu.com
"
/>
</secondCustomConfiguration>
然后通过代码获取配置属性：
Console.WriteLine(
"
----CustomConfigurationSecond---------------------
"
);
CustomConfigurationSecond settingSecond
=
CustomConfigurationSecond.Setting;
Console.WriteLine(
"
settingSecond.UrlElement.Name:
"
+
settingSecond.UrlElement.Name);
Console.WriteLine(
"
settingSecond.UrlElement.Url:
"
+
settingSecond.UrlElement.Url);
Console.WriteLine(
"
--------------------------------------------------
"
);
输出结果为：与配置文件一样
4. 以上是创建一个配置节点的情况，假如我们修改配置为
<secondCustomConfiguration>
<url name=
"
baidu
"
url=
"
http://www.baidu.com
"
/>
<url name=
"
google
"
url=
"
http://www.google.com
"
/>
</secondCustomConfiguration>
此时就会报错 “元素 <url> 只能在此节中出现一次。”怎么样修改能支持上述的情况呢？
NET为我们提供了ConfigurationElementCollection，创建UrlConfigurationElementCollection继承ConfigurationElementCollection，并且实现2个抽象方法
public
class
UrlConfigurationElementCollection : ConfigurationElementCollection
{
protected
override
ConfigurationElement CreateNewElement()
{
return
new
UrlConfigurationElement();
}
protected
override
object
GetElementKey(ConfigurationElement element)
{
return
((UrlConfigurationElement)element).Name;
}
}
创建CustomConfigurationThird : ConfigurationSection
[ConfigurationProperty(
"
urls
"
)]
[ConfigurationCollection(
typeof
(UrlConfigurationElementCollection),AddItemName
=
"
addUrl
"
,ClearItemsName
=
"
clearUrls
"
, RemoveItemName
=
"
RemoveUrl
"
)]
public
UrlConfigurationElementCollection UrlElements
{
get
{
return
(UrlConfigurationElementCollection)
this
[
"
urls
"
]; }
set
{
this
[
"
urls
"
] =
value; }
}
配置文件为
<thirdCustomConfiguration>
<urls>
<addUrl name=
"
google
"
url=
"
http://www.google.com
"
/>
<addUrl name=
"
sina
"
url=
"
http://www.sina.com
"
/>
<addUrl name=
"
360buys
"
url=
"
http://www.360buys.com
"
/>
</urls>
</thirdCustomConfiguration>
输出结果为：
好了，这次就简单的介绍下自定义配置的入门，其实NET提供了很多其他复杂的功能，没有特别需求的话以上的三种自定义配置基本上就够用了，我认为是这样的，还有一点忘记说了，如果自定义配置节点太多的话可以配置sectionGroup，如果设置了分组name是必填项，代码获取配置的时候加上sectionGroup name就可以了，如：
setting = (CustomConfigurationFirst)ConfigurationManager.GetSection("customGroup/firstCustomConfiguration");
<configSections>
<sectionGroup name=
"
customGroup
"
>
<section name=
"
firstCustomConfiguration
"
type=
"
CustomConfigurationDemo.CustomConfigurationFirst,CustomConfigurationDemo
"
/>
</sectionGroup>
<section name=
"
secondCustomConfiguration
"
type=
"
CustomConfigurationDemo.CustomConfigurationSecond,CustomConfigurationDemo
"
/>
<section name=
"
thirdCustomConfiguration
"
type=
"
CustomConfigurationDemo.CustomConfigurationThird,CustomConfigurationDemo
"
/>
</configSections>
<customGroup>
<firstCustomConfiguration id=
"
12
"
name=
"
name
"
firstProperty=
"
property2
"
/>
</customGroup>
想深入研究的话可以参考
MSDN
点击链接下载Demo
NET 自定义配置文件 Configuration