编程乐趣：C#彻底删除文件

public class AbsoluteFile
{
public event EventHandler FinishDeleteFileEvent = null;

public event EventHandler FinishDeleteFolderEvent = null;

public event EventHandler DeleteErrorEvent = null;

public string ErrorString = string.Empty;

public void DoAbsoluteDeleteFile(object filePath)
{
try
{
string filename = filePath.ToString();

if (string.IsNullOrEmpty(filename))
{
return;
}

if (File.Exists(filename))
{
File.SetAttributes(filename, FileAttributes.Normal);

double sectors = Math.Ceiling(new FileInfo(filename).Length / 512.0);

byte[] dummyBuffer = new byte[512];

RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();

FileStream inputStream = new FileStream(filename, FileMode.Open);

inputStream.Position = 0;

for (int sectorsWritten = 0; sectorsWritten < sectors; sectorsWritten++)
{
rng.GetBytes(dummyBuffer);

inputStream.Write(dummyBuffer, 0, dummyBuffer.Length);

sectorsWritten++;
}

inputStream.SetLength(0);

inputStream.Close();

DateTime dt = new DateTime(2049, 1, 1, 0, 0, 0);

File.SetCreationTime(filename, dt);

File.SetLastAccessTime(filename, dt);

File.SetLastWriteTime(filename, dt);

File.Delete(filename);

WipeDone();
}
}
catch (Exception e)
{
WipeError(e);
}
}

public void DoDeleteFolder(object folder)
{
string folderPath = folder.ToString();

if (string.IsNullOrEmpty(folderPath))
{
return;
}

DirectoryInfo direct = new DirectoryInfo(folderPath);

FileSystemInfo[] filesystem = direct.GetFileSystemInfos();

if (filesystem == null || filesystem.Length == 0)
{
direct.Delete();
}
else
{
foreach (FileSystemInfo fileItem in filesystem)
{
if (fileItem is FileInfo)
{
this.DoAbsoluteDeleteFile(fileItem.FullName);
}
else
{
DoDeleteFolder(fileItem.FullName);
}
}
}

if (this.FinishDeleteFolderEvent != null)
{
this.FinishDeleteFolderEvent(this, null);
}
}

private void WipeError(Exception e)
{
if (DeleteErrorEvent != null)
{
ErrorString = e.Message;

DeleteErrorEvent(this, null);
}
}

private void WipeDone()
{
if (FinishDeleteFileEvent != null)
{
FinishDeleteFileEvent(this, null);
}
}
}

public partial class Form1 : Form
{
private Thread dfileThread = null;

private string fileObjectPath = string.Empty;

private bool isFile = true;

public delegate void DefaulEventDelegate(object sender, EventArgs e);

public Form1()
{
InitializeComponent();
}

private void btnSelectFile_Click(object sender, EventArgs e)
{
isFile = true;

this.openFileDialog1 = new OpenFileDialog();

openFileDialog1.Multiselect = true;

openFileDialog1.Title = "请选择文件";

openFileDialog1.Filter = "所有文件(*.*)|*.*";

if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
this.txtFilePath.Text = openFileDialog1.FileName;
}

fileObjectPath = this.txtFilePath.Text.Trim();
}

private void btnSelectFolder_Click(object sender, EventArgs e)
{
isFile = false;

this.folderBrowserDialog1  = new FolderBrowserDialog();

folderBrowserDialog1.Description = "请选择文件路径";

if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
{
this.txtFolder.Text = folderBrowserDialog1.SelectedPath;
}

fileObjectPath = this.txtFolder.Text.Trim();
}

private void btnAbsoluteDelete_Click(object sender, EventArgs e)
{
this.lblHint.Visible = true;

if(string.IsNullOrEmpty(fileObjectPath))
{
MessageBox.Show("请选择要粉碎的文件和文件夹！");

return;
}

AbsoluteFile dfile = new AbsoluteFile();

dfile.DeleteErrorEvent += new EventHandler(Dfile_DeleteErrorEvent);

if (isFile)
{
dfile.FinishDeleteFileEvent += new EventHandler(Dfile_FinishDeleteFileEvent);

dfileThread = new Thread(new ParameterizedThreadStart(dfile.DoAbsoluteDeleteFile));

dfileThread.IsBackground = true;

dfileThread.Start(fileObjectPath);
}
else
{
dfile.FinishDeleteFolderEvent += new EventHandler(Dfile_FinishDeleteFolderEvent);

dfileThread = new Thread(new ParameterizedThreadStart(dfile.DoDeleteFolder));

dfileThread.IsBackground = true;

dfileThread.Start(fileObjectPath);
}

this.lblHint.Text = @"正在删除...";
}

void Dfile_DeleteErrorEvent(object sender, EventArgs e)
{
if (!this.InvokeRequired)
{
MessageBox.Show((sender as AbsoluteFile).ErrorString);
}
else
{
this.BeginInvoke(new DefaulEventDelegate(Dfile_DeleteErrorEvent), new object[] { sender, e });

}
}

void Dfile_FinishDeleteFolderEvent(object sender, EventArgs e)
{
if (!this.InvokeRequired)
{
this.lblHint.Visible = false;

MessageBox.Show("删除完毕！");
}
else
{
this.BeginInvoke(new DefaulEventDelegate(Dfile_FinishDeleteFolderEvent),new object[] { sender,e });

}
}

void Dfile_FinishDeleteFileEvent(object sender, EventArgs e)
{
if (!this.InvokeRequired)
{
this.lblHint.Visible = false;

MessageBox.Show("删除完毕！");
}
else
{
this.BeginInvoke(new DefaulEventDelegate(Dfile_FinishDeleteFileEvent), new object[] { sender, e });

}
}
}