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C# Permanently Add and Save item to combobox

everybody!
I have collection of items in combobox's properties. And I want to add new item in my combobox by writing text in combobox and then use button event:
private void button2_Click_1(object sender, EventArgs e)
{
cbx_unix_dir.Items.Add(cbx_unix_dir.Text);
}
But in next time of starting my programm - my added item doesn't exist in combobox. What do I wrong? I need all added items have been saved in my combobox for ever. May be problem in method InitializeComponents()? May be I have to add event before it?
Thank you very much.

ComboBox has no functionality to save and reload items.
You may store items into .NET Settings file on closing window and reload them on loading form:
private void Form1_Load(object sender, EventArgs e)
{
if (Settings.Default.cboCollection != null)
this.cbx_unix_dir.Items.AddRange(Settings.Default.cboCollection.ToArray());
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
ArrayList arraylist = new ArrayList(this.cbx_unix_dir.Items);
Settings.Default.cboCollection = arraylist;
Settings.Default.Save();
}
//A button to add items to the ComboBox
private void button2_Click_1(object sender, EventArgs e)
{
cbx_unix_dir.Items.Add(cbx_unix_dir.Text);
}

Edit Items in a ListBox

I am creating a program using WinForms so users can input info into textboxes on one form which then are saved into a Listbox on another form. I would like to be able to edit the items saved in the listbox by opening the original form on a button click. Really struggling with it as I can't think of the code and I can't seem to find a solution.
My Code:
private void btnAdd_Click(object sender, EventArgs e)
{
RoomDisplayForm newRoomDisplayForm = new RoomDisplayForm();
newRoomDisplayForm.ShowDialog();
if(newRoomDisplayForm.DialogResult == DialogResult.OK)
{
listBoxRooms.Items.Add(newRoomDisplayForm.value);
}
newRoomDisplayForm.Close();
}
private void btnRemove_Click(object sender, EventArgs e)
{
this.listBoxRooms.Items.RemoveAt(this.listBoxRooms.SelectedIndex);
}
private void btnEdit_Click(object sender, EventArgs e)
{
}
So i've got a Add and Remove button which work perfectly just need a solution to the edit button.
Thanks in advance

I'm guessing newRoomDisplayForm.value is a property or a public member inside the form. You just need to do something like this:
private void btnEdit_Click(object sender, EventArgs e)
{
if(listBoxRooms.SelectedIndex < 0) return;
var tmpValue = listBoxRooms.Items[listBoxRooms.SelectedIndex].ToString();
RoomDisplayForm newRoomDisplayForm = new RoomDisplayForm();
newRoomDisplayForm.value = tmpValue;
newRoomDisplayForm.ShowDialog();
//TODO: inside "newRoomDisplayForm" set the value to the textbox
// ie.: myValueTextBox.Text = this.value;
if(newRoomDisplayForm.DialogResult == DialogResult.OK)
{
// replace the selected item with the new value
listBoxRooms.Items[listBoxRooms.SelectedIndex] = newRoomDisplayForm.value;
}
}
Hope it helps!

You can simply remove the listitem in that specific position, create a new item and add it again. it's kind of replacement.

Open the last used RibbonTab when the wpf RibbonWindow is loaded

How can I return to the last used RibbonTab that was in focus when the window was last closed?

You could create a variable to hold the reference to the RibbonTab and listen to the SelectionChanged event on your Ribbon object.
MyRibbonObj.SelectionChanged += delegate(object sender, SelectionChangedEventArgs args)
{
RibbonTab rt = ((sender as Ribbon).SelectedItem as RibbonTab);
MyReferenceToRibbonTab = rt;
}
This way you keep track of the latest selected RibbonTab within your Ribbon.
PS: code might needs tweaks. I didn't test it.

Create a setting LastRibbonTab
Save the last tab used in MainWindow_Closed
MainWindow_Closed(object sender, EventArgs e)
{
Properties.Settings.Default.LastRibbonTab = (MyRibbon.SelectedItem as RibbonTab).Header.ToString();
Properties.Settings.Default.Save();
}
Select the last tab in MainWindow_Loaded
private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
Init();
foreach (RibbonTab r in MyRibbon.Items)
if (r.Header.ToString() == Properties.Settings.Default.LastRibbonTab)
{
MyRibbon.SelectedItem = r;
break;
}
}

First mouse click event on an item in a listbox doesn't trigger the function

I am trying to do something like: when a user select an item on a listbox, then the function listboxClicked will be triggered. However, the first click often does not able to trigger the function. It only triggers the function when I click the same item or another item for the second time.
May I know what's wrong with my code? Thank you.
My Code:
private void listbox_SelectedIndexChanged(object sender, EventArgs e)
{
listbox.MouseClick += listboxClicked;
}
private void listboxClicked(object sender, EventArgs e)
{
if (listbox.SelectedIndex != -1)
{
//do something
}
}

Try this one:
Listbox1_SelectedValueChanged(object sender, EventArgs e)
{
Listbox listbox = (Listbox)sender;
MessageBox.Show(listbox.SelectedItem.ToString());
}

How to change the checked state of a ToolStripItem in Winforms?

When I look it up, they list it as having a .Checked property. But both in Visual Studio and on msdn, it doesn't list any kid of Checked property.
ContextMenuStrip menu = new ContextMenuStrip ( );
var menuItem = menu.Items.Add ( "CheckedItem" );
//menuItem.Checked?
Is there a way to do this?

You need to cast to ToolStripMenuItem:
((ToolStripMenuItem)menuItem).Checked = true;

I had 2 checked items on or off, so I used this format:
private void onToolStripMenuItem_Click(object sender, EventArgs e)
{
offToolStripMenuItem.Checked = false;
}
private void offToolStripMenuItem_Click(object sender, EventArgs e)
{
onToolStripMenuItem.Checked = false;
}

This code will change StripMenuItem checked state after every mouse click.
Note: Tool Strip menu item name is: uruchomZSystememToolStripMenuItem
private void uruchomZSystememToolStripMenuItem_Click(object sender, EventArgs e)
{
uruchomZSystememToolStripMenuItem.Checked = !uruchomZSystememToolStripMenuItem.Checked;
}