How To show message box when listbox items count reaches 0

Question

I have a timer in My win app.

The timer interval is 3 seconds and deletes one item from listbox.

Here is the code:

private void timer3_Tick(object sender, EventArgs e)
{
    timer3.Enabled = false;
    if (listBox1.Items.Count > 0)
    {
        listBox1.Items.RemoveAt(0);
        progressBar1.Increment(1);
        groupBox2.Text = listBox1.Items.Count.ToString();
        timer3.Enabled = true;
    }
}

I want a message box to show that "listBox1 is clear" when listBox1.Items.Count == 0

thank you

possible duplicate of [Show a message box from a class in c#?](http://stackoverflow.com/questions/715206/show-a-message-box-from-a-class-in-c) — Austinh100, Jun 20 '14 at 16:04
I recommend disabling `timer3` before showing the `MessageBox` otherwise every 3 seconds a new `MessageBox` will popup. — Asad Ali, Jun 20 '14 at 16:16

score 1 · Accepted Answer · answered Jun 20 '14 at 16:04

Pretty simple, if it's not > 0, it must be == 0, so you can do an else { ... } and put a message box in.

private void timer3_Tick(object sender, EventArgs e)
{
    timer3.Enabled = false;
    if (listBox1.Items.Count > 0)
    {
        listBox1.Items.RemoveAt(0);
        progressBar1.Increment(1);
        groupBox2.Text = listBox1.Items.Count.ToString();
        timer3.Enabled = true;
    }
    else
    {
        MessageBox.Show("The list box is clear.");
    }
}

score 0 · Answer 2 · answered Jun 20 '14 at 16:06

private void timer3_Tick(object sender, EventArgs e)
{
timer3.Enabled = false;
if (listBox1.Items.Count > 0)
{
listBox1.Items.RemoveAt(0);
progressBar1.Increment(1);
groupBox2.Text = listBox1.Items.Count.ToString();
timer3.Enabled = true;
}
else {
messagebox.show("listBox1 is clear");
}
}

How To show message box when listbox items count reaches 0

2 Answers2