Copyright ©2021-2022 Mike King.
Licensed using the MIT licence. See the License.txt file in the solution root for more information.
Plugins is a simple library for dynamically loading, using and unloading plugin assemblies.
This solution uses .Net 6.0.
To create a plugin first create a two standard library projects, one containing the plugin interface and the other the plugin classes themselves. (See the DotDoc.Plugins.Test.CalculatorInterface / DotDoc.Plugins.Test.Calculator projects used by the unit tests for an example.)
In the method that will host the plugins create an instance of the Plugin class. Pass in the path / filename of the plugin library. There is a static helper method in Plugin called GetPluginFileName which when passed a plugin name with no extension adds any prefix / suffix needed for the current platform e.g., a .dll suffix for Windows or a lib prefix and .so suffix for Linux.
Plugin is a disposable class when the instance is disposed then the plugin assemblies are unloaded.
To create an instance of a class held within the plugin call the CreateInstance method passing either the full name of the class or the type of the class and optionally any constructor arguments. The type can be obtained by calling the GetPluginType method with the full name of the class or by looking in the type collection returned by PluginTypes. If the class created is disposable, then remember to dispose it before disposing of the plugin as the assembly will be unloaded.
string pluginFileName = Path.Combine(@"c:\temp\pluginassemblies", Plugin.GetPluginFileName("Calculator"));
using Plugin plugin = new (pluginFileName);
ICalculator addInstance = plugin.CreateInstance<ICalculator>("Calculator.Add");
int result = addInstance.Calculate(1, 1);