How to add a "Click Event" to a class? in C#

Question

So this is how far I got. (not that much I know) but I have something like this: A class called "SplashScreen"

private DynamicButton dynButton;

public override void Init(ContentManager Content)
    {
        base.Init(Content);

        dynButton = new DynamicButton("Test", new Vector2(450, 100), Color.White);} 

private void Dyn_Click(object sender, EventArgs e)
    {
        dynButton.ObjColor = Color.DarkOrange; //I want to do stuff here
    }

public override void Update(GameTime gameTime)
    {
        base.Update(gameTime);
        dynButton.Update(gameTime);
        dynButton.Click += Dyn_Click;
    }

And in my Dynamic Button class as follows:

   public event EventHandler Click;

   public override void Update(GameTime gameTime)
    {
        base.Update(gameTime);
        this.Click += DynamicButton_Click;
    }

    private void DynamicButton_Click(object sender, EventArgs e)
    {

    }

I don't really know how to get the Click event right. So like I have to check my bounds from the object with my mouse that's what I know but how can I make it that the events fires. I just want to call like dynButton.Click += myMethod and in this method I would do stuff. Hope you understand what I mean.(I'm pretty new)

How to: Implement Events in Your Class : https://msdn.microsoft.com/en-us/library/5z57dxz2(v=vs.90).aspx — Zein Makki, Nov 19 '16 at 11:31
Are you sure you want a click event? XNA/Monogame used an update paradigm that calls an Update method 60 times per second and typically, you would poll the mouse/keyboard/controller for the keys/buttons you are using in your game and if the poll results in a key/button press, then you call the appropriate method. — Steve H, Nov 20 '16 at 00:03

score 2 · Accepted Answer · answered Nov 28 '16 at 11:19

Xna and Monogame call the Update method between 30 and 60 times per second on a normal situation (based on the device).

This means that, if you want to use events; it's a really bad idea to subscribe to them on the method itself as you will get a new subscription every time. In the code you posted, you subscribe to the event 60 times per second!

public event EventHandler Click;

public override void Update(GameTime gameTime)
{
    base.Update(gameTime);
    this.Click += DynamicButton_Click; // Called 60 times per frame on a PC!
}

I'm not saying you shouldn't subscribe on such a method, you could but based on a condition. Never do it freely.

That being said, what you want is to subscribe to the event in a safe place and then fire it when a condition is met. The subscription, in you scenario, would take place on the Splash screen:

public override void Init(ContentManager Content)
{
    base.Init(Content);

    dynButton = new DynamicButton("Test", new Vector2(450, 100), Color.White);
    dynButton.Click += SomeoneClicked;
} 

private void SomeoneClicked(object sender, EventArgs e)
{
    // Your code here.
}

The dynamic button is the one responsible for firing the event (but not responding to the event itself).

public event EventHandler Click;

public override void Update(GameTime gameTime)
{
    base.Update(gameTime);
    if(this.Click != null)
        Click(null, null);
}

You can find more info about EventHandlers on the MSDN. As a final note, and I think this is the biggest problem you are facing; you need to know exactly when to fire the event. based on your comments, you need to check for a particular condition based on the position of the mouse, which is easily done via the MouseState provided methods:

MouseState ms = Mouse.GetState();
var positionX = ms.X;
var positionY = ms.Y;

How to add a "Click Event" to a class? in C#

1 Answers1