C # Plugin practices

Plugin is a flexible and scalable modular mechanism. Many Application blocks of Microsoft use the Plugin structure. This article discusses a kind of practice of Plugin in C.
Plugin is an object that implements IPlugin using the Reflection mechanism in C # based on a unified interface. If the interface is IPlugin, the following code block indicates the code segment that dynamically generates the IPlugin object. dllName indicates the dll file name that implements the IPlugin interface class:

Public IPlugin LoadPlugin (string dllName)
{
Assembly asm = AppDomain. CurrentDomain. Load (dllName );
Foreach (Type t in asm. GetTypes ()){
Foreach (Type iface in t. GetInterfaces ()){
If (iface. Equals (typeof (IPlugin ))){
Return (System. Activator. CreateInstance (t) as IPlugin;
}
}
}
Return null;
}
 
Java also has a Reflection mechanism to implement Plugin, which is roughly like (IPlugin) Class. forName (className). newInstance. C ++ can use DLL simulation because of the Reflection mechanism. In the DLL, a global function and interface are export, and the global function returns the pointer of the object that implements the interface.

Microsoft has an article on Provider Pattern. In this article, another C # instantiation method with parameters is provided.