說起.NET的配置文件,.NET的開發人員無人不知,無人不用,如下面的配置節點,基本上每個.NET開發的項目都會出現像下面的配置,出現在App.config或者Web.config中
<connectionStrings>
<add name=
"
DbConnectionString
"
connectionString=
"
....
"
/>
</connectionStrings>
<appSettings>
<add key=
"
LogFilePath
"
value=
"
c:/Logs/
"
/>
</appSettings>
一般的項目用NET提供的配置節點就已經夠用了,但是如果項目的配置文件很多很多,appSettings就會出現大量的配置,基本上都是key和value的組合,如果再加上命名不易讀,維護就會很麻煩,又或者你自己寫了一個框架給別人用,需要定義符合自己的配置節點,所以有些時候我們需要自定義一些配置.
其實NET已經提供了自定義配置的基類和一些接口,對創建自定義的配置已經非常方便了,下面就開始做幾個簡單的實例吧
1. 創建一個控制臺的項目?CustomConfigurationDemo，添加App.Config并且引用System.configuration dll
2. 創建?CustomConfigurationFirst類繼承ConfigurationSection，添加屬性long Id， string Name，string FirstProperty，并且通過ConfigurationPropertyAttribute標記屬性，第一個字符串為 配置文件中配置的屬性名，DefaultValue為默認值，其他屬性就不一一介紹了，可以參考ConfigurationPropertyAttribute的注釋信息。
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; }
}
}
我們自定義的配置創建好了，現在需要添加配置到App.config文件中，如下圖所示，首先需要創建configSections，把自定義的節點加進去，name隨便填寫（填寫的值將會與代碼中的ConfigurationManager.GetSection("firstCustomConfiguration")名稱對應），type需要填寫自定義配置節點類的全名稱和程序集
<?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>
一切準備就緒，用控制臺程序打印出我們剛剛配置的屬性看看吧！
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("--------------------------------------------------");
運行結果如下，和我們配置文件中設置的值一樣，是不是感覺很簡單。
3. 有時候我們需要在配置文件中加一些子節點，應該怎么做呢？
先創建一個?UrlConfigurationElement：ConfigurationElement，在ConfigurationElement里面添加屬性和在Section里面添加是一樣的，然后我們創建一個CustomConfigurationSecond : ConfigurationSection，并創建一個屬性的類型是UrlConfigurationElement的，如下圖所示：
[ConfigurationProperty(
"
url
"
)]
public
UrlConfigurationElement UrlElement
{
get
{
return
(UrlConfigurationElement)
this
[
"
url
"
]; }
set
{
this
[
"
url
"
] =
value; }
}
?此時配置文件添加的配置為：
<secondCustomConfiguration>
<url name=
"
baidu
"
url=
"
http://www.baidu.com
"
/>
</secondCustomConfiguration>
?
?然后通過代碼獲取配置屬性：
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(
"
--------------------------------------------------
"
);
?
輸出結果為：與配置文件一樣
4. 以上是創建一個配置節點的情況，假如我們修改配置為
<secondCustomConfiguration>
<url name=
"
baidu
"
url=
"
http://www.baidu.com
"
/>
<url name=
"
google
"
url=
"
http://www.google.com
"
/>
</secondCustomConfiguration>
?
?此時就會報錯 “元素 <url> 只能在此節中出現一次。”怎么樣修改能支持上述的情況呢？
NET為我們提供了ConfigurationElementCollection，創建UrlConfigurationElementCollection繼承ConfigurationElementCollection，并且實現2個抽象方法
public
class
UrlConfigurationElementCollection : ConfigurationElementCollection
{
protected
override
ConfigurationElement CreateNewElement()
{
return
new
UrlConfigurationElement();
}
protected
override
object
GetElementKey(ConfigurationElement element)
{
return
((UrlConfigurationElement)element).Name;
}
}
?
創建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; }
}
?
配置文件為
<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>
?輸出結果為：
好了，這次就簡單的介紹下自定義配置的入門，其實NET提供了很多其他復雜的功能，沒有特別需求的話以上的三種自定義配置基本上就夠用了，我認為是這樣的，還有一點忘記說了，如果自定義配置節點太多的話可以配置sectionGroup，如果設置了分組name是必填項，代碼獲取配置的時候加上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>
?
想深入研究的話可以參考
MSDN
點擊鏈接下載Demo
NET 自定義配置文件 Configuration