Use Linq and Reflection to Activate Interface and Execute a Method.

I created a simple ICommand interface similar to the one in System.Windows.Input:

interface ICommand  
{  
    string Description { get; }  
    bool CanExecute(object parameter);  
    void Execute();  
}

In my project I created a bunch of classes that implement my ICommand interface and I wanted to find and execute them all. I came up with two ways to do this, using a List and reflection.

List
#

This is very direct and easy but as I added new commands the list began to grow. Also I had to remember to add my commands to the list as I created them.

string separator = new string('=', 100);  
var commandsToExec = new List<ICommand>  
{  
    new Commands.TestEntityConnectionStringBuilderCommand(),  
    new Commands.BenchmarkingExampleCommand(),  
    new Commands.FastTokenizerBenchmarkCommand(),  
    new Commands.LinqToXmlTest01()  
};  

foreach (var cmd in commandsToExec)  
    if (cmd.CanExecute(null))  
    {  
        Console.WriteLine("{0}{1}{2}{1}{0}{1}", separator, Environment.NewLine, 
                            cmd.Description);  
        cmd.Execute();  
        Console.WriteLine("{1}{0}{1}{1}", separator, Environment.NewLine);  
    }

Reflection
#

Using linq I find all the types in my Assembly that implements the ICommand interface. I then loop through the results, create an instance of the object and cast it as a ICommand and then call the execute method.

var commandClasses = from type in Assembly.GetExecutingAssembly().GetTypes()  
    where type.GetInterfaces().Contains(typeof(ICommand))  
    select type;  

foreach (var commnadType in commandClasses)  
{  
    var cmd = Activator.CreateInstance(commnadType) as ICommand;  
    if (cmd.CanExecute(null))  
    {  
        Console.WriteLine("{0}{1}{2}{1}{0}{1}", separator, Environment.NewLine, 
                        cmd.Description);  
        cmd.Execute();  
        Console.WriteLine("{1}{0}{1}{1}", separator, Environment.NewLine);  
    }  
}

List#

Reflection#

List
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Reflection
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