Question

If I do not create an “Edit->Copy” menu item and assign it the shortcut keys “CTRL+C”, then I can select a control (RichTextBox, DataGridView, etc..) and hit “CTRL+C” and the control itself will handle the copy. I can copy text out, and paste it into notepad, etc..

Now throughout my whole form, I have a lot of controls. But I have a custom control that I want to make clear that I handle Copy functionality for. So I added the ShortcutKey CTRL+C to Edit->Copy, and by default it is set to Enabled.

Now, I have to implement an event handler for the ‘click’ event on that menu item. If I explicitly put in code to handle the copy, then it works:

public void menuEditCopy_Click(object sender, EventArgs e)
{
    myCustomControl.Copy();
}

However, now Copy does not work on any other type of control. My first inclination was to find out the type of control that has focus, and implement a limited set of copy code for each of them:

public void menuEditCopy_Click(object sender, EventArgs e)
{
    if (this.ActiveControl is MyCustomControl)
    {
        ((MyCustomControl)this.ActiveControl).Copy();
    }
    else if (this.ActiveControl is RichTextBox)
    {
        ((RichTextBox)this.ActiveControl).Copy();
    }
}

etc…

However, my controls are added to a SplitContainer, and debugging shows that this.ActiveControl is set to the splitcontainer instance, not the control, even though I know that control is selected.

So my last thought is to literally check if every control has focus:

public void menuEditCopy_Click(object sender, EventArgs e)
{
    if (myCustomControl.Focused)
    {
        myCustomControl.Copy();
    }
    else if (richTextBox1.Focused)
    {
        richTextBox1.Copy();
    }
}

I would like to avoid this if possible, it is a lot of controls, and if I add a new control, I would need to update it. Is there a better way of doing this?

Thanks

Answer 1

A SplitContainer implements ContainerControl, so you could check for either one and look for it’s ActiveControl instead. ContainerControl is the base class, so I would go for that – you might catch another type of container as well:

private void DoCopy(Control control)
{
    if(control is ContainerControl)
        DoCopy(control.SelectedControl);
    else if(control is MyCustomControl)
        ((MyCustomControl)control).Copy();
    else if(control is RichTextBox)
        ((RichTextBox)control).Copy();
    else
        throw new NotSupportedException("The selected control can't copy!");
}

void menuEditCopy_Click(object sender, EventArgs e)
{
    DoCopy(this.ActiveControl);
}