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How to show the numeric position from a selected item in a listbox in a label

Sorry for the confusing title but here is my situation: When I select an item from a listbox I want a label showing that item's number. For example if I choose the fifth item in the listbox the label should show "Item number 5 is selected".
How do I do this?

This is simple. All you need to do to get the index of the selected item in the listbox is to use the SelectedIndex property which returns the zero-based index of the selected item. If you want a one-based index instead, just add 1 to the index.
int index = listBox.SelectedIndex;
label.Text = $"Item number {index + 1} is selected.";

C# Find the Selected State of all items in a ListBox

I have found many examples on how to find the selected items in a listbox and how to iterate through a listbox;
for(int index=0;index < listBox1.Items.Count; index++)
{
MessageBox.Show(listBox1.Items[index].ToString();
}
or
foreach (DataRowView item in listBox1.Items)
{
MessageBox.Show(item.Row["ID"].ToString() + " | " + item.Row["bus"].ToString());
}
While these methods work great for the selected items, what I have yet to figure out, or find, is how to get the selected state, selected and unselected, of every item in a listbox, as the above only gives the selected.
Basically, I need something like this;
for(int index=0;index < listBox1.Items.Count; index++)
{
if (index.SelectedMode == SelectedMode.Selected)
{
MessageBox.Show(listBox1.Items[index].ToString() +"= Selected";
}
else
{
MessageBox.Show(listBox1.Items[index].ToString() +"= Unselected";
}
}
I've found a snippet that said to use (listBox1.SelectedIndex = -1) to determine the selected state however I've not figured out or found how to build a loop around this to check each item in the listbox.
I've also read that I should put the listbox items into an array, but again nothing about getting the selected state of each item in the listbox.
I know I'll have to iterate through the listbox to accomplish what I'm needing, pretty sure it'll be one of the above loops, however I have yet to find how to extract the selected state of each item in the listbox.
I'm using VS2013, C# Windows Form, .NET Framework 4.0
Thanks in advance for any advice/direction.

This will get you the unselected items:
List<string> unselected = listBox1.Items.Cast<string>().Except(listBox1.SelectedItems.Cast<string>());
You can loop over that list like this:
foreach(string str in listBox1.Items.Cast<string>().Except(listBox1.SelectedItems.Cast<string>()))
{
System.Diagnostics.Debug.WriteLine($"{str} = Not selected");
}
I've made the assumption that you're using string as your item type. If you want to use something else then just replace string with your type and it should still work.
You then loop over the unselected items to do whatever you want with them then loop over listBox1.SelectedItems to do whatever you want with the selected ones.

You can use GetSelected method of the ListBox. It returns a value indicating whether the specified item is selected.
For example, the following code, sets the value of selected to true if the item at index 0 (the first item) is selected:
var selected = listBox1.GetSelected(0);
Example
Te following loop, shows a message box for each item, showing the item text and item selection status:
for (int i = 0; i < listBox1.Items.Count; i++)
{
var text = listBox1.GetItemText(listBox1.Items[i]);
var selected = listBox1.GetSelected(i);
MessageBox.Show(string.Format("{0}:{1}", text, selected ? "Selected" : "Not Selected"));
}

c# select listview item if two listviews contains it

In my program I have 2 listviews and 1 button.
When I press the button, every listview item in the first listview will be selected in the second listview. The items in the first listview always exist in the second listview, but not the other way around.
I'm having trouble with selecting the items in the second listview. I'm trying to get the index with IndexOf.
foreach (ListViewItem item in firstListView.Items)
{
int index = secondListView.Items.IndexOf(item);
secondListView.Items[index].Selected = true;
}
I always get an error that index is -1 when I click the button. And I don't understand what I'm doing wrong.
SOLUTION
So what I tried to do here finding an index of an item which belongs to a different listview, and it doesn't work like that. Even though the text in both listviews are the same, the listview items are not identically the same because they are reference types.
I was not able to use the Text property because items could have the same text. So the solution I had was putting an unique integer in the Tag property for each ListViewItem. Since integers are value types, I can use that integer to check whether the ListViewItem in the first listview is in the second.
// Loop through each item in the first listview
foreach (ListViewItem item1 in firstListView.Items)
{
// For each item in the first listview, loop through the second listview to find if it's there
foreach (ListViewItem item2 in secondListView.Items)
{
// Check if item1 is identical to item2 by looking at its tag
if (int.Parse(item1.Tag) == int.Parse(item2.Tag))
{
// The item has been found and will be selected!
item2.Selected = true;
}
}
}

You can use such linq query to select items of the second list which exist in the first list too:
var items = from i1 in listView1.Items.Cast<ListViewItem>()
from i2 in listView2.Items.Cast<ListViewItem>()
where i1.SubItems.Cast<ListViewItem.ListViewSubItem>()
.Where((s, i) => s.Text != i2.SubItems[i].Text).Count() == 0
select i2;
items.ToList().ForEach(x => { x.Selected = true; });
Note:
When to try to use secondListView.Items.IndexOf method to find an item which belongs to the firstListView you can not expect it to find the item. The item you are trying to find its index, doesn't exists in second listview's item collection. You should find items using Text property of the item and sub items.

Well the same item obviously cant exist in two different lists.
If the text is the same, then try looking by it:
foreach (ListViewItem listViewItem in l1.Items)
{
var item = l2.Items.Cast<ListViewItem>().Where(lvi => lvi.Text == listViewItem.Text);
item.Selected=true;
}
Or:
foreach (ListViewItem listViewItem in l2.Items.Cast<ListViewItem>()
.Where(lvi => l1.Items.Cast<ListViewItem>().Any(lvi2 => lvi.Text == lvi2.Text))
{
listVieItem.Selected=true;
}

IndexOf returns -1 if it cannot find the object passed to it in the list. My guess is that you have an issue with your equality comparison. Do the objects in the lists implement IComparable? Otherwise they may not be finding the items correctly and are reverting to a bad equality comparison. ListViewItem may not be comparing how you expect.

you can try finding the item by text and then get the index like this
foreach (ListViewItem item in firstListView.Items)
{
var itm = secondListView.FindItemWithText(item.Text);
int index = secondListView.Items.IndexOf(itm);
secondListView.Items[index].Selected = true;
secondListView.Select();
}
what FindItemWithText will do is get the item in secondListView which will be of same name as in firstListView and IndexOf will get the index of item in secondListView
Edit
This solution is good when you have two lists whose items are same and does not include any repetition in name else if you have two items in secondListView with same name FindItemWithText will get the first item only.

How to get listbox selected item value

I am working with C# .NET 4.0
I am trying to get the value of a single selected item in a listbox.
This is how I populate the control:
this.files_lb.DataSource = DataTable object
In my designer, I have specified file_name as the DisplayMember and file_id as the DisplayValue
After selecting an item in the listbox, I tried the following to get the value:
this.files_lb.SelectedValue.ToString()
But all it returns is "System.Data.DataRowView".
At this link : Getting value of selected item in list box as string
someone suggested -
String SelectedItem = listBox1.SelectedItem.Value
However, 'Value' is not an option when I try this.
How can I get the ValueMember value from a single selected item in a listbox?

var text = (listBox1.SelectedItem as DataRowView)["columnName"].ToString();
Replace columnName with the name of the column you want to get data from, which will correspond with a column in your datasource.
Also watch out for nulls if there's no selected item.

It really should be this easy; I have the following in a click event for button to make sure I wasn't over simplifying it in my head:
private void button1_Click(object sender, EventArgs e)
{
string selected = listBox1.GetItemText(listBox1.SelectedValue);
MessageBox.Show(selected);
}
And the result:
Edit
It looks like your issue may be from not setting a property on the control:
Select the ListBox control
Click the little arrow to show the binding / items options
Select Use Data Bound Items
If I deselect that box, I get the exact same behavior you are describing.

var selectedValue = listBoxTopics.SelectedItem;
if (selectedValue != null)
{
MessageBox.Show(listBoxTopics.SelectedValue.ToString());
}

You may need to set the DataValueField of the listbox.
NewEmployeesLB.DataSource = newEmployeesPersons.DataList.Select(np => new
ListItem() { Text = np.LastName + ", " + np.FirstName, Value = np.PersonID.ToString() }).ToList();
NewEmployeesLB.DataTextField = "Text";
NewEmployeesLB.DataValueField = "Value";
NewEmployeesLB.DataBind();

Searching DataGrid for matching values

I Have a data grid which can be queried based on a comboBox choice .
My code (shown below) is meant to search through the datagrid and if it finds a row with a matching piece of text it is meant to move the datagrids selected index to the corresponding row.
for (int i = 0; i <= DashBoard_DataGrid.Columns.Count - 1; i++)
{
if (DashBoard_DataGrid.Rows[0].ToString().ToLower().Contains(comboBox9.Text.ToString().ToLower()))
{
value = dr.Cells[i].Value.ToString();
// return dr.Cells[i].RowIndex;
DashBoard_DataGrid.SelectedCells[i].RowIndex = dr.Cells[i].RowIndex;
}
}
However I am getting the following error
Error 7 Property or indexer 'System.Windows.Forms.DataGridViewCell.RowIndex' cannot be assigned to -- it is read only
Does anyone know how to fix this error ? searching online hasn't givin a solution

You are trying to change a SelectedCell's row index, which is read-only. If you are trying to change the selected row, you need to set the SelectedIndex for the DataGrid.
DashBoard_DataGrid.SelectedIndex = dr.Cells[i].RowIndex;
Also, try changing SelectedCells to SelectedRows.

try this
.
DashBoard_DataGrid.ClearSelection();
DashBoard_DataGrid.Rows[3].Selected = true;
or if you want to select a specific cell, then
DashBoard_DataGrid.ClearSelection();
DashBoard_DataGrid[0, i].Selected = true;
this will select the first column of the desired row..