C# – What’s the difference between the WebConfigurationManager and the ConfigurationManager

asp.netcconfigurationmanagernetwebconfigurationmanager

What's the difference between the WebConfigurationManager and the ConfigurationManager?

When should I use one over the other?

UPDATED

I just looked at the WebConfigurationManager, and for some reason, you can't access the connection strings as you do in the ConfigurationManager (like an array). Can anyone tell me why MS made it like this? It seems to be a pain to get the connection string you need using the WebConfigurationManager.

UPDATED AGAIN with CAVEAT!

If you don't have a reference to the System.Configuration namespace added to your project, then Visual Studio will show an error when you try and access the WebConfigurationManager.ConnectionStrings like an array!

Best Answer

WebConfigurationManger knows how to deal with configuration inheritance within a web application. As you know, there could be several web.config files in one applicaion - one in the root of the site and any number in subdirectories. You can pass path to the GetSection() method to get possible overridden config.

If we'd looke at WebConfigurationManager with Reflector then things are clear:

public static object GetSection(string sectionName)
{
    ...
    return ConfigurationManager.GetSection(sectionName);
}

public static object GetSection(string sectionName, string path)
{
    ...
    return HttpConfigurationSystem.GetSection(sectionName, path);
}

This is the style that Microsoft tends to use in their examples.

It appears that the guidance in this area may have changed, as StyleCop now enforces the use of the C# specific aliases.

.net – What’s the difference between struct and class in .NET

In .NET, there are two categories of types, reference types and value types.

Structs are value types and classes are reference types.

The general difference is that a reference type lives on the heap, and a value type lives inline, that is, wherever it is your variable or field is defined.

A variable containing a value type contains the entire value type value. For a struct, that means that the variable contains the entire struct, with all its fields.

A variable containing a reference type contains a pointer, or a reference to somewhere else in memory where the actual value resides.

This has one benefit, to begin with:

value types always contains a value
reference types can contain a null-reference, meaning that they don't refer to anything at all at the moment

Internally, reference types are implemented as pointers, and knowing that, and knowing how variable assignment works, there are other behavioral patterns:

copying the contents of a value type variable into another variable, copies the entire contents into the new variable, making the two distinct. In other words, after the copy, changes to one won't affect the other
copying the contents of a reference type variable into another variable, copies the reference, which means you now have two references to the same somewhere else storage of the actual data. In other words, after the copy, changing the data in one reference will appear to affect the other as well, but only because you're really just looking at the same data both places

When you declare variables or fields, here's how the two types differ:

variable: value type lives on the stack, reference type lives on the stack as a pointer to somewhere in heap memory where the actual memory lives (though note Eric Lipperts article series: The Stack Is An Implementation Detail.)
class/struct-field: value type lives completely inside the type, reference type lives inside the type as a pointer to somewhere in heap memory where the actual memory lives.

Best Answer

Related Solutions

C# – the difference between String and string in C#

This is the style that Microsoft tends to use in their examples.

.net – What’s the difference between struct and class in .NET

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