对动态添加的嵌套控件进行迭代

Question

I have a GroupBox on an WinForm. Another GroupBox is added in run time within the first GroupBox.

Few PictureBox controls are added within the second GroupBox.

Now I would like to iterate the PictureBoxes.

Currently my code is:

foreach (Control gbFirst in this.Controls)
{
    GroupBox firstGroupBox = gbFirst as GroupBox; //First GroupBox
    if (firstGroupBox != null)
    {
        foreach (Control gbSecond in firstGroupBox.Controls)
        {
            GroupBox secondGroupBox = gbSecond as GroupBox; //Second groupBox
            if (secondGroupBox != null)
            {
                foreach (Control item in secondGroupBox.Controls)
                {
                    var pb = item as PictureBox; // PictureBox
                    if (pb != null)
                    {
                        string pbTag = pb.Tag.ToString();
                        string customTag = ipAddress + "OnOff";
                        if (pb.Tag.ToString() == ipAddress + "OnOff")
                        {
                            MethodInvoker action = delegate
                            {
                                pb.Image = Properties.Resources.MobiCheckerOnPng16;
                            };
                            pb.BeginInvoke(action);
                            break;
                        }
                    }
                }
            }

        }
    }
}

But, unlike the above, I think there may be an easy or smart way to do it.

Is it so?

Answer 1

A generic function to use for any control type in any container at any levels:

public static List<T> FindControls<T>(Control container, bool dig) where T : Control
{
    List<T> retVal = new List<T>();
    foreach (Control item in container.Controls)
    {
        if (item is T)
            retVal.Add((T)item);
        if (dig && item.Controls.Count > 0)
            retVal.AddRange(FindControls<T>(item, dig));
    }
    return retVal;
}

The dig variable controls whether or not to iterate through child container controls. For example if you want to find all PictureBox controls starting from your first GroupBox (gbFirst), you must call

FindControls<PictureBox>(gbFirst, true);

If set dig to false, only controls in the input cotainer will be enumerated.