Question

im making a file explorer tool in c# .. im using ListView to explore files

but i have an issue when i copy items(files)

public ListView.SelectedListViewItemCollection copiedItems;

private void btnCopy_Click(object sender, EventArgs e)
    {
        copiedItems = listView1.SelectedItems;
        infoLabel.Text = "Item(s) copied to clipboard.";
    }

private void Paste()
    {
        if (copiedItems != null)
        {
            foreach (ListViewItem item in copiedItems)
            {
                if (File.Exists(item.ToolTipText))
                {
                    if (MessageBox.Show(item.ToolTipText + "is already exists\r\nDo you want to overwrite it?"
                    , "Overwrite", MessageBoxButtons.OKCancel, MessageBoxIcon.Asterisk) == DialogResult.OK)
                    {
                        File.Copy(item.ToolTipText, currAddress, true);
                        infoLabel.Text = "Item(s) Pasted.";
                    }
                    return;
                }
                File.Copy(item.ToolTipText, currAddress, false);
                infoLabel.Text = "Item(s) Pasted.";
            }
        }
    }

when i change the folder that i am into(currAddress) .. the paste doesn’t work because the

 ListView.SelectedListViewItemCollection copiedItems 

changed to null. .. here’s my explorer code

private void DirRecursive(string path)
    {
            DirectoryInfo dir = new DirectoryInfo(path);
            currAddress = path;
            txtAddress.Text = path;
            _iconListManager.ClearLists();
            listView1.Items.Clear();
            foreach (DirectoryInfo folder in dir.GetDirectories())
                {
                    if ((folder.Attributes & FileAttributes.Hidden) == FileAttributes.Hidden)
                        continue;
                    ListViewItem item = new ListViewItem();
                    item.Text = folder.Name;
                    item.Tag = (object)folder.Parent;
                    item.ToolTipText = folder.FullName;
                    item.ImageIndex = _iconListManager.AddFolderIcon(folder.FullName);
                    listView1.Items.Add(item);
                }
                foreach (FileInfo file in dir.GetFiles())
                {
                    if ((file.Attributes & FileAttributes.Hidden) == FileAttributes.Hidden)
                        continue;
                    ListViewItem item = new ListViewItem();
                    item.Text = file.Name;
                    item.Tag = (object)file.Directory.Parent;
                    item.ToolTipText = file.FullName;
                    item.ImageIndex = _iconListManager.AddFileIcon(file.FullName);
                    item.SubItems.Add(CnvrtUnit(file.Length));
                    listView1.Items.Add(item);
                }

is there any explanation why copiedItems changed to null and how can i fix it ?

thanks in advance 🙂

Answer 1

Instead of

public ListView.SelectedListViewItemCollection copiedItems;

use

public List<string> copiedItems;

Change btnCopy_Click to this:

private void btnCopy_Click(object sender, EventArgs e)
    {
        copiedItems = listView1..SelectedItems.Cast<ListViewItem>().Select(li => li.ToolTipText).ToList();
        infoLabel.Text = "Item(s) copied to clipboard.";
    }

change Paste to this:

private void Paste()
    {
        if (copiedItems != null)
        {
            foreach (string item in copiedItems)
            {
                if (File.Exists(item))
                {
                    if (MessageBox.Show(item + "is already exists\r\nDo you want to overwrite it?"
                    , "Overwrite", MessageBoxButtons.OKCancel, MessageBoxIcon.Asterisk) == DialogResult.OK)
                    {
                        File.Copy(item, currAddress, true);
                        infoLabel.Text = "Item(s) Pasted.";
                    }
                    return;
                }
                File.Copy(item, currAddress, false);
                infoLabel.Text = "Item(s) Pasted.";
            }
        }
    }