WebClient真的对.NET 3.5 CF不可用吗? [英] Is WebClient really unavailable to .NET 3.5 CF?
问题描述
我的应用程序以Windows CE为目标;它使用了Compact Framework
My app targets Windows CE; it uses the Compact Framework
我复制了一些其他使用WebClient的可运行代码,但无法编译,并说:"找不到类型或名称空间名称'WebClient'(您是否缺少using指令或程序集?参考?)"
I copied over some elsewhere-working code that uses WebClient, but it won't compile, saying, "The type or namespace name 'WebClient' could not be found (are you missing a using directive or an assembly reference?)"
我确实有一个正在使用System.Net;"
I do have a "using System.Net;"
由于该错误,我还得到:"名称'HttpRequestHeader'在当前上下文中不存在"
Because of that error, I also get, "The name 'HttpRequestHeader' does not exist in the current context"
代码是:
private static void SendXMLFile(string xmlFilepath, string uri)
{
using (var client = new WebClient())
{
client.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(xmlFilepath))
{
String line;
while ((line = sr.ReadLine()) != null)
{
sb.AppendLine(line);
}
}
// I don't know why the prepended equals sign is necessary, but it is
string allLines = "=" + sb.ToString();
var result = client.UploadString(uri, "POST", allLines);
}
}
如果WebClient 适用于我的方案,我需要什么参考/使用方式?
If WebClient is available for my scenario, what Reference/using do I need?
如果在我的情况下 无法使用WebClient,那有什么追索权/替代权?
If WebClient is not available for my scenario, what recourse/replacement is there?
如果没有 追索权/替代权,谁能/将给我送来一瓶黑莓白兰地?
If there is no recourse/replacement, who can/will send me a bottle of Blackberry Brandy?
我正在尝试根据情况调整答案,但立即遇到问题:
I'm trying to adapt the answer to my situation, but run into a problem right away:
HttpWebRequest request = (HttpWebRequest) WebRequest.Create(uri);
request.Method = method;
问题是无法识别方法"(得到红色波浪状的情况,并且"名称方法"在当前上下文中不存在"
The problem is that "method" is not recognized (gets a case of the red squigglys and "The name 'method' does not exist in the current context"
我知道-方法是传入的字符串;我需要的是:
I see - method is a string passed in; what I need is:
request.Method = "POST";
更新3
我不确定这是否会真正起作用,但是它确实可以编译,而且似乎很有意义,所以我将尝试一下:
UPDATE 3
I'm not sure yet if this will actually work, but it does compile, and seems to make sense, so I'll try it out:
private static string SendXMLFile(string xmlFilepath, string uri, int timeout)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
request.KeepAlive = false;
request.ProtocolVersion = HttpVersion.Version10;
request.Method = "POST";
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(xmlFilepath))
{
String line;
while ((line = sr.ReadLine()) != null)
{
sb.AppendLine(line);
}
byte[] postBytes = Encoding.UTF8.GetBytes(sb.ToString());
if (timeout < 0)
{
request.ReadWriteTimeout = timeout;
request.Timeout = timeout;
}
request.ContentLength = postBytes.Length;
request.KeepAlive = false;
request.ContentType = "application/x-www-form-urlencoded";
try
{
Stream requestStream = request.GetRequestStream();
requestStream.Write(postBytes, 0, postBytes.Length);
requestStream.Close();
using (var response = (HttpWebResponse)request.GetResponse())
{
return response.ToString();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
request.Abort();
return string.Empty;
}
}
}
推荐答案
WebClient不存在,尽管实际上并没有那么重要.您可以使用HttpWebRequest来完成大部分工作.
WebClient doesn't exist, though really it's really not all that important to have. You can get by with a HttpWebRequest for most any of what you'll be doing.
遵循这些原则(来自OpenNETCF扩展):
Something along these lines (from the OpenNETCF Extensions):
private string SendData(string method, string directory, string data, string contentType, int timeout)
{
lock (m_syncRoot)
{
directory = directory.Replace('\\', '/');
if (!directory.StartsWith("/"))
{
directory = "/" + directory;
}
string page = string.Format("{0}{1}", DeviceAddress, directory);
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(page);
#if !WINDOWS_PHONE
request.KeepAlive = false;
request.ProtocolVersion = HttpVersion.Version10;
#endif
request.Method = method;
// turn our request string into a byte stream
byte[] postBytes;
if (data != null)
{
postBytes = Encoding.UTF8.GetBytes(data);
}
else
{
postBytes = new byte[0];
}
#if !WINDOWS_PHONE
if (timeout < 0)
{
request.ReadWriteTimeout = timeout;
request.Timeout = timeout;
}
request.ContentLength = postBytes.Length;
request.KeepAlive = false;
#endif
if (contentType.IsNullOrEmpty())
{
request.ContentType = "application/x-www-form-urlencoded";
}
else
{
request.ContentType = contentType;
}
try
{
Stream requestStream = request.GetRequestStream();
// now send it
requestStream.Write(postBytes, 0, postBytes.Length);
requestStream.Close();
using (var response = (HttpWebResponse)request.GetResponse())
{
return GetResponseString(response);
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
request.Abort();
return string.Empty;
}
}
}
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