C# 判断远程文件是否存在

　　　　 /// <summary>
/// 判断远程文件是否存在
/// </summary>
/// <param name="url">url地址</param>
/// <returns></returns>
public bool FileExists(string url)
{
//ture为存在，false为不存在
bool result = false;
WebResponse response = null;
try
{
WebRequest req = WebRequest.Create(url);
response = req.GetResponse();
result = response == null ? false : true;
}
catch (Exception ex)
{
result = false;
}
finally
{
if (response != null)
{
response.Close();
}
}
return result;
}