關于StreamReader.ReadToEnd方法 - s0611163－IT工程師數位筆記本

文章出處

以前寫抓取網頁的代碼喜歡用ReadToEnd，因為簡單省事，后來發現，在爬取網頁的時候，如果網速很慢，ReadToEnd超時的幾率很大。使用Read改寫后，超時幾率大大減小，完整代碼如下：

/// <summary>
/// HttpPost
/// </summary>
public static string HttpPost(string url, string data)
{
    byte[] bArr = ASCIIEncoding.UTF8.GetBytes(data);

    // 設置參數
    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
    request.CookieContainer = m_Cookie;
    request.Method = "POST";
    request.ContentType = "application/x-www-form-urlencoded";
    request.ContentLength = bArr.Length;
    request.UserAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0)";

    Stream postStream = request.GetRequestStream();
    postStream.Write(bArr, 0, bArr.Length);
    postStream.Close();

    //發送請求并獲取相應回應數據
    HttpWebResponse response = request.GetResponse() as HttpWebResponse;
    //直到request.GetResponse()程序才開始向目標網頁發送Post請求
    Stream responseStream = response.GetResponseStream();
    //返回結果網頁（html）代碼
    MemoryStream memoryStream = new MemoryStream();
    bArr = new byte[1024];
    int size = responseStream.Read(bArr, 0, (int)bArr.Length);
    while (size > 0)
    {
        memoryStream.Write(bArr, 0, size);
        size = responseStream.Read(bArr, 0, (int)bArr.Length);
        Thread.Sleep(1);
    }
    string content = Encoding.UTF8.GetString(memoryStream.ToArray());
    return content;
}