c#实现http文件下载

//url 下载的路径
//FileName  保存的文件名
public static void DownLoadFile(String url ,String FileName)
{
    try
    {
        FileStream outputStream = new FileStream(Application.StartupPath + @"\"+FileName, FileMode.Create);
        WebRequest request = WebRequest.Create(url);
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        Stream httpStream =response.GetResponseStream();
        long cl = response.ContentLength;
        int bufferSize = 2048;
        int readCount;
        byte[] buffer = new byte[bufferSize];
        readCount = httpStream.Read(buffer, 0, bufferSize);
        while (readCount > 0)
        {
            outputStream.Write(buffer, 0, readCount);

            readCount = httpStream.Read(buffer, 0, bufferSize);
        }
        httpStream.Close();

        outputStream.Close();

        response.Close();
    }
    catch (Exception ex)
    {
        MessageBox.Show("文件下载失败错误为" + ex.Message.ToString(), "温馨提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
    }
}