同时为C＃Winform中的多个动态控件触发事件

Question

I have N number of dynamically added PictureBoxes in FlowLayoutPanel . When I create them I attach event handlers to them. For example:

for(int i=0;i<x;i++) {    
    var pe= new PictureBox();
    pe.MouseUp+=mouseup;
    pe.MouseDown+=mouseDown;
    pe.MouseMove+=mouseMove;
    pe.Paint+=paint;
}

My goal is to fire those events for all picture boxes whenever I work with any one of them. For example, if I move one picturebox (1st/2nd/3rd/.../n ) all others will move automatically, if I zoom any box, others will zoom automatically. How can I fire events simultaneously for all pictureboxes when I work with anyone.

If I try for example:

void mouseWheel(object sender, MouseEventArgs e) {
    var control=(PictureBox)sender;
    var parent=control.parent;
    var pictureBoxes=parent.ofType<PictureBox>();

    foreach(pb in pictureBoxes) {
                //do something
    }
}

It only works for the picture box I am working with.

Answer 1

You need to call a method instead of raising the event.

Create some methods and put logic on the methods, then in the event handler, first extract information that you need, then call suitable method with parameters.

For example:

void pictureBox_MouseWheel(object sender, MouseEventArgs e)
{
    //Some parameter that you extract from eventArgs or somewhere else
    int zoomFactor = e.Delta;

    //Call the method on your picture boxes
    foreach (var p in pictureBoxes)
    {
        Zoom(p, zoomFactor);
    }
}

//The method that contains logic of zoom on a picture box
public void Zoom(PictureBox p, int zoomFactor)
{
    //It is just an example, not a real logic
    p.SizeMode = PictureBoxSizeMode.Zoom;
    p.Width += (zoomFactor * 10);
    p.Height += (zoomFactor * 10);
}

I supposed you have added all your pictureboxes in a List<PictureBox> when you created them.

Also if you have added your picture boxes to a Controls collection of a control, for example theControl , then you can find them later this way:

var pictureBoxes = theControl.Controls.OfType<PictureBox>().ToList();

Answer 2

It looks like you already have a list of picture boxes. So, try modifying your functions (for example your Zoom function) to work for all picture boxes in the list, rather than just the one picture box.

In other words, don't try to call the event handler for each picture box, make each event handler call a function, which modifies all picture boxes.