Display same message twice and thrice using listView

Question

I am working in a listview where I am trying to add role in it. I have validation method that prevent the listview to have duplicate role. The problem is it throws same message twice when I select another list item of listView and it throws same message thrice when i select the scrollbar of list View. I think the using the listView.BeginEdit() in wrong way. Please ! help me to sort this problem

Code :

private void AddDefaultRoles()
{
    ListViewItem lvi = new ListViewItem("Reader");
    listViewRoles.Items.Add(lvi);

    lvi = new ListViewItem("Writer");
    listViewRoles.Items.Add(lvi);

    lvi = new ListViewItem("Administrator");
    listViewRoles.Items.Add(lvi);

    lvi = new ListViewItem("Delete");
    listViewRoles.Items.Add(lvi);

    lvi = new ListViewItem("Admin");
    listViewRoles.Items.Add(lvi);

    lvi = new ListViewItem("Contributor");
    listViewRoles.Items.Add(lvi);

    lvi = new ListViewItem("Designer");
    listViewRoles.Items.Add(lvi);
}

private void button1_Click(object sender, EventArgs e)
{
    if (string.IsNullOrEmpty(textBox1.Text))
        textBox1.Text = "New Role";

    ListViewItem lvi = new ListViewItem(textBox1.Text);
    listViewRoles.Items.Add(lvi);

    lvi.Selected = true;
    lvi.BeginEdit();
}


private void listViewRoles_AfterLabelEdit(object sender, LabelEditEventArgs e)
{
    ListViewItem lvi = listViewRoles.Items[e.Item];
    string newName = e.Label;
    if (newName == null)
        newName = lvi.Text;

    if (!ValidateRoleName(newName, e.Item))
    {
        lvi.BeginEdit();
        return;
    }
}

private void listViewRoles_BeforeLabelEdit(object sender, LabelEditEventArgs e)
{

}

private bool ValidateRoleName(string name, int itemIndex)
{
    const bool validName = true;
    if ((string.IsNullOrEmpty(name.Trim()))) //empty name
    {
        MessageBox.Show(this, "empty role name", "Rename failed");
        return !validName;
    }
    if (NameExists(name, itemIndex)) //name already exists
    {
        MessageBox.Show(this, "already exists", "Rename failed");
        return !validName;
    }

    return validName;
}

private bool NameExists(string newName, int itemIndex)
{
    const bool nameExists = true;

    for (int i = 0; i < listViewRoles.Items.Count; ++i)
    {
        if (itemIndex == i)
            continue;
        if (string.Compare(listViewRoles.Items[i].Text.TrimEnd(), newName.TrimEnd(), true) == 0)
        {
            return nameExists;
        }
    }
    return !nameExists;
}

Edit (from misplaced answer):

private void listViewRoles_AfterLabelEdit(object sender, LabelEditEventArgs e)
{
    ListViewItem lvi = listViewRoles.Items[e.Item];
    string newName = e.Label;
    if (newName == null)
        newName = lvi.Text;

    if (_checkRoleName)
    {
        if (!ValidateRoleName(newName, e.Item))
        {
            _checkRoleName = false;
            lvi.BeginEdit();
            return;
        }
    }
    else
    {
        _checkRoleName = true;
        lvi.BeginEdit();
    }
}

    this.listViewRoles.AfterLabelEdit += new System.Windows.Forms.LabelEditEventHandler(this.listViewRoles_AfterLabelEdit);
    this.listViewRoles.BeforeLabelEdit += new System.Windows.Forms.LabelEditEventHandler(this.listViewRoles_BeforeLabelEdit);

When I try the above code it show message box once when i changed the selected index but still when i click the scroll bar, it will called the AfterLabelEdit event so the message called twice. I need a proper solution such that if the added listviewitem is already exists in listview, the added listViewItem persist in edit mode until its name is changed or unique.

have you tried stepping thru your code opposed to just running it..? — MethodMan
why is this const bool nameExists = true; declared this way why is it not bool nameExists = true; — MethodMan
even if we make const bool nameExist as bool nameExists doesn't affect my problem. The problem is when I called lvi.BeginEdit() from listViewRoles_AfterLabelEdit it will called listViewRoles_AfterLabelEdit twice when we select anther listview item and thrice when we select the listview scrollbar. — user1370468
I am just wondering if you would ever return false since you can't change the value of a constant.. Problem or not I am seeing a potential problem perhaps you should read up on Constants — MethodMan

MethodMan MethodMan · Accepted Answer · 2012-08-08T16:10:05

0

votes

You have your call in the wrong event

Use the 'AfterLabelEdit' event.

MSDN AfterLabelEdit

Display same message twice and thrice using listView

1 Answers