process problem

[C# Programming]

hi

after i unzip file and try to copy him, i get error process is used
by another program

what can be the problem ? (work on WinForm - C#)

ZipInputStream sampleInputStream = new ZipInputStream(File.OpenRead(UnZIP_ZipFile));
ZipEntry sampleFile = null;
string sampleOutputDirectoy = UnZIP_RegFile;
int sampleSize = 2048;
sampleInputStream.Password = "12345";
while ((sampleFile = sampleInputStream.GetNextEntry()) != null)
{
sampleSize = 2048;
if (Path.GetFileName(sampleFile.Name) != string.Empty)
{
string sampleFilePath = sampleOutputDirectoy + @"\" + sampleFile.Name;
FileStream sampleFileStream = File.Create(sampleFilePath);
byte[] sampleFileData = new byte[sampleSize];
while (true)
{
sampleSize = sampleInputStream.Read(sampleFileData, 0, sampleFileData.Length);
if (sampleSize > 0)
sampleFileStream.Write(sampleFileData, 0, sampleSize);
else
break;
}
sampleFileStream.Close();
sampleFileStream.Dispose();
}

}
sampleInputStream.Close();
sampleInputStream.Dispose();
MessageBox.Show(" ");