Specifying a specific file type for ListView interface

Question

I have created a file Explorer in C# to select a file from a list of directories, however I have limited knowledge on how to specify the file type itself.

I only want .xls files to be displayed, not all files displayed. How do I go about this? I currently have:

TreeNode newSelected = e.Node;
listView1.Items.Clear();
DirectoryInfo nodeDirInfo = (DirectoryInfo)newSelected.Tag;
ListViewItem.ListViewSubItem[] subItems;
ListViewItem item = null;

foreach (DirectoryInfo dir in nodeDirInfo.GetDirectories())
{
    item = new ListViewItem(dir.Name, 0);
    subItems = new ListViewItem.ListViewSubItem[]
              {new ListViewItem.ListViewSubItem(item, "Directory"),
       new ListViewItem.ListViewSubItem(item,
    dir.LastAccessTime.ToShortDateString())};
    item.SubItems.AddRange(subItems);
    listView1.Items.Add(item);
}
foreach (FileInfo file in nodeDirInfo.GetFiles())
{
    item = new ListViewItem(file.Name, 1);
    subItems = new ListViewItem.ListViewSubItem[]
              { new ListViewItem.ListViewSubItem(item, "File"),
       new ListViewItem.ListViewSubItem(item,
    file.LastAccessTime.ToShortDateString())};

    item.SubItems.AddRange(subItems);
    listView1.Items.Add(item);
}

Answer 1

You could change your 2nd for loop to:

foreach (var file in nodeDirInfo.GetFiles())
{
    if (file.Extension == ".xls")
    {
        // Do the stuff with the file
    }
}

or

foreach (var file in nodeDirInfo.GetFiles()
    .Where(file => 
        string.Equals(file.Extension, ".xls")))
{
    // Do the stuff with the file
}

For your purposes I would recommend using OpenFileDialog, as it sounds like you just need the user to select a file from the directory:

var openFileDialog1 = new OpenFileDialog();

openFileDialog1.InitialDirectory = @"C:\Path\To\Directory\";
openFileDialog1.Filter = "Excel Files (*.xls)|*.xls";

if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
    var selectedFilePath = openFileDialog1.FileName;
}