“活动”控件和“焦点”控件之间的区别

Question

I'm trying to figure out why these two lines of code sometimes return different values:

var focus = FindFocusedControl(_targetForm).Name;
var active = _targetForm.ActiveControl.Name;

FindFocusedControl comes from here :

private static Control FindFocusedControl(Control control)
{
    var container = control as ContainerControl;
    while (container != null)
    {
        control = container.ActiveControl;
        container = control as ContainerControl;
    }
    return control;
}

Is my active simply the one least able to be drilled down into? Does it depend on whether the control that actually has focus is inside a UserControl ?

Answer 1

_targetForm.ActiveControl will return the control on the form that either has the focus or one of its child controls has the focus.

Your FindFocusedControl implementation does the same, but recursively checks the child controls until it reaches the control that has focus, and returns that.

So for controls directly on the form, they will return the same value, but for controls stacked on panels or other containers, the returned values will be different.