I am thinking of abstracting Event action in order to make further alteration/implementation/maintenance easy since the project I am currently working on has volatile requirement. So I thought of the following concept. I created an implementation of IEventAction which ex. handles closing of planning in my application, I made IEventAction extends IEventAction so I can manage all EventAction using a generic collection; and using a factory, I will get the appropriate event by passing the keypress key to the factory to resolve the correct event as shown in the code below.

interface IEventAction {


interface IEventAction<T> : IEvent {
    void Fire(T factor);
    bool CheckCondition(T factor); //check the condition to fire the event

class PlanningClose : IEventAction<string> {
    GroupBox _gpb;
    public PlanningClose(GroupBox gpb){
        this._gpb = gpb;

    public void Fire(string factor) {
        this._gpb.SendToBack(); //hide planning groupeBox

    public bool CheckCondition(string factor){
        return factor == "*"; //"*" is keyboard key for close.

class frmMain : Form {
    //logic here
    void registerActions() {
        ActionsFactory.Register(new PlanningClose(this._gpbPlanning));
    //logic here
    void frmMain_KeyPress(object sender, KeyPressEventArgs e){
        //during resolve the factory checks if the event is suited be executing 
        //CheckCondition(T factor) and return it if appropriate
        IEventAction evt = ActionsFactory.Resolve<string>(e.keychar);  
    //logic here

The problem here is that I am managing a lot of key presses in frmMain_KeyPress where I am using the same key several times for different purpose, the problem here is I cant figure out a proper way to handle this problem and keep Action as abstract as possible. I thought about registering named action and resolving them by name also, but I have never used this technique.

ActionsFactory.Register("close_planning", new PlanningClose(this._gpbPlanning);
ActionsFactory.Resolve<string>("close_planning", e.KeyChar);

Does anyone have a better way of implementing this problem. Thank you.


It sounds like you want to resolve event actions based on more than just the e.KeyChar. I have seen this problem solved by passing in a second argument to the Resolve function which could be named something like KeyPressContext. Basically you would want to supply an extra object with metadata about the context in which the key was pressed and use that information to determine how to resolve the action.

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