Accessing another variable in the same class with a click event

问题

I have the following problem:

I want to access a variable inside my class through a mouse-click.

My Class:

public class Box
{

    public Label LabelDown = new Label();
    public byte SavedID;

    public Box(EventHandler InsideEvent)
    {

        LabelDown.Text = null;
        LabelDown.Size = new Size(96, 32);
        LabelDown.Visible = true;
        LabelDown.Click += new EventHandler(InsideEvent);

        SavedID = 0;

    }
}

Now, I created an Array of this class in a Form, using:

 Box[] myBox = new Box[5];

In the code for initializing my Form, I've added this:

  for (byte j = 0; j <= myBox.Length(); j++)
     {
         mybox = new Box(Box_goInside_Click)
         Controls.Add(Box[j].LabelDown);
     }

now the Click event handler is:

   void Box_goInside_Click(object sender, EventArgs e)
     {

        //here i want to access the saved ID of MyBox that uses this Label
        Dosomething( whatever comes here. SavedID)

     }

I hope you understand what my problem is... if I use base, or anything else, it will get to Object, because it sees only my Label, but not that its part of my class Box.

回答1:

You have few options:

put a reference of each Box inside the Tag property of each Label.
handle the event Click event inside the Box class and then call the handler replacing the original sender (Label) with the Box itself.

First solution:

public Box(EventHandler InsideEvent)
{
    LabelDown.Text = null;
    LabelDown.Size = new Size(96, 32);
    LabelDown.Visible = true;
    LabelDown.Click += new EventHandler(InsideEvent);
    LabelDown.Tag = this;

    SavedID = 0;
}

void Box_goInside_Click(object sender, EventArgs e)
{
    Box box = (Box)((Control)sender).Tag;

    // Do your stuff
}

Second solution:

public class Box
{
    public Label LabelDown = new Label();
    public byte SavedID;

    public Box(EventHandler InsideEvent)
    {

        LabelDown.Text = null;
        LabelDown.Size = new Size(96, 32);
        LabelDown.Visible = true;
        LabelDown.Click += OnLabelClick;

        SavedID = 0;

        _insideEvent = InsideEvent;
    }

    private EventHandler _insideEvent;

    private OnLabelClick(object sender, EventArgs e)
    {
        if (_insideEvent != null)
            _insideEvent(this, e);
    }
}

void Box_goInside_Click(object sender, EventArgs e)
{
    Box box = (Box)sender;

    // Do your stuff
}

来源：https://stackoverflow.com/questions/13382688/accessing-another-variable-in-the-same-class-with-a-click-event

标签

labels