C# 4 and .NET 4

Managing the file system ❘ 777
You create the project as a standard C# Windows application in Visual Studio 2010. Add the various
text boxes and the list box from the Windows Forms area of the toolbox. You also renamed the
controls with the more intuitive names of textBoxInput, textBoxFolder, buttonDisplay, buttonUp,
listBoxFiles, listBoxFolders, textBoxFileName, textBoxCreationTime, textBoxLastAccessTime,
textBoxLastWriteTime, and textBoxFileSize.
Next, you need to indicate that you will be using the System.IO namespace:
using System;
using System.IO;
using System.Windows.Forms;
You need to do this for all the file-system-related examples in this chapter, but this part of the code will not
be explicitly shown in the remaining examples. You then add a member field to the main form:
public partial class Form1: Form
{
private string currentFolderPath;
code download FileProperties.sln
currentFolderPath stores the path of the folder whose contents are displayed in the list boxes.
Next, you need to add event handlers for the user-generated events. The possible user inputs are:
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User clicks the Display button — You need to determine whether what the user has typed in the main
text box is the path to a file or folder. If it is a folder, you list the files and subfolders of this folder in
the list boxes. If it is a file, you still do this for the folder containing that file, but you also display the
file properties in the lower text boxes.
User clicks a filename in the Files list box — You display the properties of this file in the lower
text boxes.
User clicks a folder name in the Folders list box — You clear all the controls and then display the
contents of this subfolder in the list boxes.
User clicks the Up button — You clear all the controls and then display the contents of the parent of
the currently selected folder.
Before you see the code for the event handlers, here is the code for the methods that do all the work. First,
you need to clear the contents of all the controls. This method is fairly self-explanatory:
protected void ClearAllFields()
{
listBoxFolders.Items.Clear();
listBoxFiles.Items.Clear();
textBoxFolder.Text = "";
textBoxFileName.Text = "";
textBoxCreationTime.Text = "";
textBoxLastAccessTime.Text = "";
textBoxLastWriteTime.Text = "";
textBoxFileSize.Text = "";
}
code download FileProperties.sln
Next, you define a method, DisplayFileInfo(), that handles the process of displaying the information for
a given file in the text boxes. This method takes one parameter, the full pathname of the file as a String,
and works by creating a FileInfo object based on this path:
protected void DisplayFileInfo(string fileFullName)
{
FileInfo theFile = new FileInfo(fileFullName);
if (!theFile.Exists)
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