Event Handler

[EntryTeam]

Hi, all.
I'm trying to move picturebox event handler to my own class.
The event handler looks like this:

private void MyPicBox_Click(object sender, System.EventArgs e)
{
    // my code here
}

The problem is: I don't know how to call this method from my class and what arguments to pass to it.

Suppose, my class's name is X.
Than, in the MainForm (where exactly in the MainForm) should be something like this:

X.MyPicBox_Click(?, ?)

[GaryTexmo]

You need to connect the event handler of your picture box to the method you want to handle it. To do this, create a new event handler... if you're using visual studio than just type MyPicBox.Click and it should come up with instructions on what to do, but I think the code is something like...

MyPicBox.Click += new EventHandler(X.MyPicBox_Click);

You could put this in the constructor of the form that defines MyPicBox, or the initialize method, or the form load method, etc...

I hope that helps!

[EntryTeam]

@GaryTexmo
I didn't post all of my code, so it's a little bit more complicated:

// how do i pass "some_class_copy" to MyPicBox_Click ? 
public void MyPicBox_Click(object sender, System.EventArgs e, 
        ref SomeClass some_class_copy)
{
  SomeMethod(ref some_class_copy); 
}

[GaryTexmo]

So you have an extra parameter that the event needs to send? I have no idea how to make an already defined method take an extra argument. Out of curiosity, what exactly is some_class_copy? Is this something you need to pass directly, or is there a way you can get it from within the event handler itself?

[EntryTeam]

@GaryTexmo
I can get it working in another way.
What I am doing/trying to do here is to "clean up" my MainForm, so there wont be any method bodies - only method calls and global variables.
This should make a code to look more professional.

[GaryTexmo]

If it helps any, I'm not sure it's a good idea to handle an event from an object in one class with a handler in another class. I'm probably not expressing myself very well, but I blame Monday... my head's totally not in it :D

What I mean is, wouldn't it be better to just have the form that contains the picture box handle the event from the picture box, then make use of the class to do whatever it needs to do?

class Main
  ...
  private PictureBox myPicBox = new PictureBox();
  private X myX = new X();
  ...
  public Main()
  {
    ...
    myPicBox.Click += new EventHandler(myPicBox_Click);
    ...
  }
  ...
  public void myPicBox_Click(object sender, System.EventArgs e)
  {
    myX.DoSomething(sender, e, ...);
  }
  ...
}

[tlhintoq]

Having one class subscribe to an event in another class isn't a problem so long as they aren't on different threads.

The simple way to think about this is that you want your Picturebox to raise an event and your 'someclass' to listen for the event. What the event is can be whatever you want to write. Personally I try to keep the raised event to a minimum of information and have all the details in the class that is listening. The class raising the event shouldn't really know much if anything about the class that is listening. It just yells out "This just happened", and the class listening is responsible for how it reacts.

Perhaps instead of using the built-in event of "Click" you need to create a custom event with a custom Args class. When the picturebox is clicked, it's click handler can then raise your custom event.

public void MyPicBox_Click(object sender, System.EventArgs e)
{
  CustomArgs myCustomArgs = new CustomArgs();
  myCustomArgs.Name = "bob";
  myCustomArgs.Age = 27;
  myCustomArgs.Something = ref mySomething;
  MyCustomEvent(myCustomArgs);
}

Then you listen for the customevent

FromWithBox.MyPicBox.CustomEvent += new CustomEventHandler(CustomEvent_handler); 

[EntryTeam]

2GaryTexmo

myX.DoSomething(sender, e, ...);

Good one. Interesting "way around" :))
2tlhintoq

CustomArgs myCustomArgs = new CustomArgs();

This one's also very interesting - a way to pass whole "pack" of arguments as a single object - I guess this will help me much, 'cause I'm already almost getting lost within methods having huge lists of arguments. And this is only a beginning of my project :))