|
Sometimes, it is necessary where we will require a
custom configuration sections or elements where we can put some configuration
settings. For example, when you develop a custom framework component or custom
control for your project you may want to put its configuration setting in a more
specific way rather than putting it into appSettings. For this purpose, the
System.Configuration namespace has 3 abstract classes packed with it namely
ConfigurationSection, ConfigurationElement and
ConfigurationElementCollection.
Moving forward, we will understand how to create custom
configuration sections and elements in this article. For understanding this
article, we will assume we are creating eLearning site where you want to store
the information related to the eLearning like below.
<eLearning category="Cooking" mode="Offline">
</eLearning>
Steps
1. Create an Asp.Net application with C# as language in your Visual Studio 2008.
2. Include a class called
eLearningConfigSection in your solution and inherit it from ConfigurationSection
class in System.Configuration namespace. Create two public properties called
Category and Mode by decorating it with ConfigurationProperty attribute. You can
configure the name, default value and specify if the property is mandatory using
ConfigurationProperty attribute. See below,
public class eLearningConfigSection :
ConfigurationSection
{
[ConfigurationProperty("category", DefaultValue =
"Technology", IsRequired = false)]
public string Category
{
get
{
return this["category"] as string;
}
}
[ConfigurationProperty("mode", IsRequired = true)]
public string Mode
{
get
{
return this["mode"] as string;
}
}
}
Please note that whatever name you specify in
ConfigurationProperty attribute will be the actual property name in custom
configuration section in web.config file and is case sensitive. Also, include
System.Configuration namespace for the above code to work.
3. Now, to use the above
configuration section in your web.config file we need to first register the
section with its type in <configSections>. Navigate to the Web.Config file
and find the configSections node. Here, we can see other sections registered by
the .netframework already. Include our eLearningSection and the type which the
ASP.Net should use for our new configuration section like below,
<configSections>
<!-- Other sections -->
<section name="eLearning"
type="eLearningConfigSection"/>
</configSections>
Make sure you are configuring this setting at right
place otherwise you may get an error like “Unrecognized configuration section
eLearning.” This setting needs to be directly inside <configSections>
tag.
4. We can now define our custom
config section like below.
<eLearning category="Cooking" mode="Offline">
</eLearning>
Make sure you are putting this section out of
<system.web> tag.
5. That’s it; you are now done
with adding your new custom config section. Next, we will see how to access or
read these settings from code.
Read Custom Config Values in Code
We can use
ConfigurationManager.GetSection("sectionname") method to read the values from
custom config section. See the below code,
protected void Page_Load(object sender, EventArgs
e)
{
eLearningConfigSection elearnsetting =
ConfigurationManager.GetSection("eLearning") as eLearningConfigSection;
Response.Write(elearnsetting.Category);
Response.Write("<br>");
Response.Write(elearnsetting.Mode);
}
The GetSection() method will read xml config values and
will desterilize it to the .net object, eLearningConfigSection in our case.
At times, we may also need to add another element inside
the custom configuration section. For example, see below.
<eLearning category="Cooking" mode="Offline">
<company name="Classic Cooks"
location="IN"></company>
</eLearning>
To do this, we need to define this new object and make
it as a member of our eLearningConfigSection class. Also, this new object should
inherit from ConfigurationElement class. To do this, add a new class to your
solution called as Company and define 2 properties Name and Location. See
below,
public class Company : ConfigurationElement
{
[ConfigurationProperty("name", IsRequired = true)]
public string Name
{
get
{
return this["name"] as string;
}
}
[ConfigurationProperty("location", DefaultValue = "US",
IsRequired = false)]
public string Location
{
get
{
return this["location"] as string;
}
}
}
Again, note that whatever name you specify in
ConfigurationProperty attribute will be the actual property name in custom
configuration section and is case sensitive. Also, include System.Configuration
namespace for the above code to work.
Next, we have to go back to our eLearningConfigSection
class and add Company object as a new property. Refer the below code,
public class eLearningConfigSection :
ConfigurationSection
{
[ConfigurationProperty("category", DefaultValue =
"Technology", IsRequired = false)]
public string Category
{
get
{
return this["category"] as string;
}
}
[ConfigurationProperty("mode", IsRequired = true)]
public string Mode
{
get
{
return this["mode"] as string;
}
}
[ConfigurationProperty("company")]
public Company Company
{
get
{
return this["company"] as
Company;
}
}
}
That’s it. You can define a new element called company
with name and location inside eLearning section like below,
<eLearning category="Cooking" mode="Offline">
<company name="Classic Cooks"
location="IN"></company>
</eLearning>
To read the above setting in code,
protected void Page_Load(object sender, EventArgs e)
{
eLearningConfigSection elearnsetting =
ConfigurationManager.GetSection("eLearning") as eLearningConfigSection;
Response.Write(elearnsetting.Category);
Response.Write("<br>");
Response.Write(elearnsetting.Mode);
Response.Write("<br>");
Response.Write(elearnsetting.Company.Name);
Response.Write("<br>");
Response.Write(elearnsetting.Company.Location);
Response.Write("<br>");
}
|