Question

我在一个实例中成功地将字符串保存为文件的内容，而在另一个实例中，它失败了。为什么呢？

以下是成功尝试的代码（创建名为＆＃34的文件; platypi.xml＆＃34;将原始文件中的内容（位于手持设备上）创建为服务器/ PC上的新文件：

public enum HttpMethods
{
    GET = 0,
    PUT,
    POST,
    DELETE,
    HEAD,
    OPTIONS,
    LIST,
    UNKNOWN
}

private void menuItem2_Click(object sender, System.EventArgs e)
{
    String uri = "http://192.168.125.50:21608/api/inventory/sendXML/duckbill/platypus/platypi";
    RESTfulMethods rm = new RESTfulMethods();
    rm.SendXMLFile(uri);
}

public void SendXMLFile(string uri)
{
    StringBuilder sb = new StringBuilder();
    StreamReader sr = new StreamReader(@"\My Documents\heavens2Murgatroid.XML");
    String line;
    while ((line = sr.ReadLine()) != null)
    {
        sb.Append(line); 
        sb.Append("\r\n");
    }
    sr.Close();

    string strData = @sb.ToString();
    strData = strData.Replace("\"", "'"); // <= Needed?
    CreateRequestNoCredentials(uri, HttpMethods.POST, strData, "application/xml"); 
}

public static HttpWebRequest CreateRequestNoCredentials(string uri, HttpMethods method, string data, string contentType)
{
    WebRequest request = WebRequest.Create(uri);
    try
    {
        request.Method = Enum.ToObject(typeof(HttpMethods), method).ToString();
        request.ContentType = contentType; 
        ((HttpWebRequest)request).Accept = contentType;
        ((HttpWebRequest)request).KeepAlive = false;
        ((HttpWebRequest)request).ProtocolVersion = HttpVersion.Version10;

        if (method != HttpMethods.GET && method != HttpMethods.DELETE)
        {
            byte[] arrData = Encoding.UTF8.GetBytes(data);
            request.ContentLength = arrData.Length;
            using (Stream oS = request.GetRequestStream())
            {
                oS.Write(arrData, 0, arrData.Length);
            }
        }
        else
        {
            request.ContentLength = 0;
        }
        }
    catch (WebException webex)
    {
        HttpWebResponse hwr = (HttpWebResponse) webex.Response;
        HttpStatusCode hsc = hwr.StatusCode;
        MessageBox.Show(string.Format("{0} Status code == {1}", webex.Message, hsc.ToString()));
    }
    return request as HttpWebRequest;
}

以下是不成功尝试的代码：

// This code also uses the HttpMethods enum

public static void WriteIt2(string fileName, string data)
{
    // "data" does contain valid data here; fileName is also a valid name
    if (File.Exists(fileName))
    {
        MessageBox.Show(String.Format("{0} exists - deleting", fileName));
        File.Delete(fileName);
    }
    string justFileName = Path.GetFileNameWithoutExtension(fileName);
    String uri = String.Format("http://192.168.125.50:21608/api/inventory/sendXML/duckbill/platypus/{0}", justFileName);
    String bla = data.Substring(0, 102);
    MessageBox.Show(String.Format("uri is {0}; first part of data is {1}", uri, bla));
    // I do see the first part of data here in the MessageBox ("bla" and thus "data" are not empty)
    CreateRequestNoCredentials(uri, HttpMethods.POST, data, "application/xml"); 
}

// CreateRequestNoCredentials() is the same as that shown above

在这种情况下，保存文件（名为＆＃34; [fileName]＆＃34;），但文件为空。有什么区别？

Answer 1

我看到的唯一区别是第一组代码将更改后的字符串文字传递给CreateRequestNoCredentials（）方法。 string strData = @ sb.ToString（）;不确定你传递给WriteIt2方法的是什么。

为什么一个String保存到一个文件，而另一个没有，用相同的代码？

1 个答案: