Set Statusbar Text on Mouse Hover - Works for controls but not MenuItems

Question

I devised the following code for displaying a control's Tag property on mouseover. The code works fine for standard controls such as Labels and TextBoxes but I cannot get it to work for my MenuItems (more specifically ToolStripMenuItems). Could y'all please take a look at my code and tell me what I did wrong? Thanks in advance!

public void Form1_Load(object sender, EventArgs e)

{

...

this.addEventsToAllComponents(this);

}

    private void addEventsToAllComponents(Component component)
{
  if (component is MenuItem)
  {
    MenuItem menuItem = component as MenuItem;
    menuItem.Select += new EventHandler(menuItem_Select);
  }
  else if (component is Control)
  {
    Control ctrl = component as Control;
    foreach (Control control in ctrl.Controls)
    {
      control.MouseEnter += new EventHandler(this.control_MouseEnter);
      control.MouseLeave += new EventHandler(this.control_MouseLeave);
      if (control.HasChildren)
        addEventsToAllComponents(control);
    }
  }
}

    private void menuItem_Select(object sender, EventArgs e)
{
  MenuItem menuItem = sender as MenuItem;

  if (menuItem.Tag.ToString().Length > 0)
    this.toolStripStatusLabel1.Text = menuItem.Tag.ToString();
}

private void control_MouseEnter(object sender, EventArgs e)
{
  Control control = sender as Control;

  if (control.Tag.ToString().Length > 0)
    this.toolStripStatusLabel1.Text = control.Tag.ToString();
}

private void control_MouseLeave(object sender, EventArgs e)
{
  if (this.toolStripStatusLabel1.Text.ToString().Length > 0)
    this.toolStripStatusLabel1.Text = "";
}

Answer 1

You don't have any code to handle ToolStripMenuItems - They are not derived from MenuItems, so your MenuItem-handling code won't do anything for them.

Aside: for readability, you might like to use string.IsNullOrEmpty(menuItem.Tag.ToString()) to test for empty/blank strings.

Answer 2

You don't have the recursion set up for MenuItems that contain other menu items. So when it find a menuitem, it will only add the top level MenuItem, not it's children.

try adding:

foreach (MenuItem item in menuItem.MenuItems)
{
  item Select += new EventHandler(menuItem_Select);
  if (item.IsParent)
    addEventsToAllComponents(item);
}

in the section for handling MenuItems.

Answer 3

There are a few problems with your code.

1st. The Items of a MenuStrip are not children of the Item, so HasChildren will return false. Instead, they are in the Items collection of the MenuStrip. You need to handle a MenuStrip occurrence specially. Add the following code in your AddEvents... method below:

(snip...)
// old code                    
if (control.HasChildren)
    AddEventsToAllControls(control);
//add new code below
if (control is MenuStrip) {
    MenuStrip ms = control as MenuStrip;
    AddEventsToAllToolStripMenuitems(ms.Items);
}

And add the new method as follows:

private void AddEventsToAllToolStripMenuitems (ToolStripItemCollection items) {
    foreach (ToolStripItem tsi in items) {
        tsi.MouseEnter += new EventHandler(this.control_MouseEnter);
        tsi.MouseLeave += new EventHandler(this.control_MouseLeave);
        if (tsi is ToolStripMenuItem) {
            ToolStripMenuItem mi = tsi as ToolStripMenuItem;
            AddEventsToAllToolStripMenuitems(mi.DropDownItems);
        }
    }
}

2nd. ToolStripItem doesn't derive from Control, so in MouseEnter the sender as Control statement will fail (control will be null). Do something like this:

Control control = sender as Control;
if (control != null && control.Tag != null && control.Tag.ToString().Length > 0)
    this.toolStripStatusLabel1.Text = control.Tag.ToString();

ToolStripItem tsi = sender as ToolStripItem;
if (tsi != null && tsi.Tag != null && tsi.Tag.ToString().Length > 0)
    this.toolStripStatusLabel1.Text = tsi.Tag.ToString();

(I also added some null checks)

This should get you going.

Answer 4

Here is the revised code for AddEventsToAllComponents method:

private void addEventsToAllControls(Control ctrl)
{
  foreach (Control control in ctrl.Controls)
  {
    control.MouseEnter += new EventHandler(this.control_MouseEnter);
    control.MouseLeave += new EventHandler(this.control_MouseLeave);
    if (control.HasChildren)
      addEventsToAllControls(control);

    if (control is MenuStrip)
    {
      MenuStrip ms = control as MenuStrip;
      AddEventsToAllToolStripItems(ms.Items);
    }
    else if (control is ToolStrip)
    {
      ToolStrip ts = control as ToolStrip;
      AddEventsToAllToolStripItems(ts.Items);
    }
  }
}