C#递归删除文件

/// <summary>
/// 删除文件夹及子文件内文件
/// </summary>
/// <param name="str"></param>
public void DeleteFiles(string str)
{
DirectoryInfo fatherFolder = new DirectoryInfo(str);
//删除当前文件夹内文件
FileInfo[] files = fatherFolder.GetFiles();
foreach (FileInfo file in files)
{
//string fileName = file.FullName.Substring((file.FullName.LastIndexOf("\\") + 1), file.FullName.Length - file.FullName.LastIndexOf("\\") - 1);
string fileName = file.Name;
try
{
if (!fileName.Equals("index.dat"))
{
File.Delete(file.FullName);
}
}
catch (Exception ex)
{
}
}
//递归删除子文件夹内文件
foreach (DirectoryInfo childFolder in fatherFolder.GetDirectories())
{
DeleteFiles(childFolder.FullName);
}

}