使用listview项值C＃填充文本框

Question

I am populating a list-view with passwords. Then I want to take the selected items text and pass it to a text box when it is clicked.

So far I have:

 private void passwordListView_SelectedIndexChanged(object sender, EventArgs e)
    {
        ListViewItem listViewItem = new ListViewItem();
        listViewItem = passwordListView.SelectedItems[0];
        passwordTextBox.Text = listViewItem.Text;
    }

It works the first time I press it and it populates the textbox but then if I click a different password in the list-view it throws an exception.

Have I left out something blatantly obvious?

Answer 1

When the Selected Index is changed in a winforms ListView the first event is for the item that has now been deselected. So at that point SelectedItems is empty.

Check for this through if (passwordListView.SelectedItems.Count == 0) return;

After this you will get a second event, which will be for the new selection, and you can act on this.

Btw, you don't need to make a new ListViewItem as you are in your snippet, this will save the extra unnecessary creation:

ListViewItem listViewItem = passwordListView.SelectedItems[0];

Answer 2

Maybe you could try this :

private void passwordListView_SelectedIndexChanged(object sender, EventArgs e)
{
    if(passwordListView.SelectedItems.Count > 0)
        passwordTextBox.Text = passwordListView.SelectedItems.First().Text;
}