我有一个Web应用程序和一个桌面应用程序，两者都是使用服务连接的。有一个功能是从运行桌面应用程序的桌面的Web应用程序中截取屏幕截图。 我已经编写了代码来截取屏幕截图。 我唯一坚持的是如何将请求仅发送给特定用户？
现在我发送一个带有用户ID的请求，它会搜索所有正在使用该应用程序的用户，如果用户ID匹配，则会截取屏幕截图。
这是我通过所有用户进行循环的代码，因为当用户群增长时会增加额外的负担
private void StartHttpCommandDispatcher()
{
mCmdDispatcher.AddResourceLocator(new ImageLocator(SMARTer.Properties.Resources.ResourceManager));
mCmdDispatcher.AddCommand(new SpeakTextCommand());
mCmdDispatcher.RequestReceived += new HttpCommandDispatcher.RequestReceivedHandler(OnHttpRequestReceived);
mCmdDispatcher.Start(SCREEN_CAPTARE_URL);
}
private void ShowHttpRequest(string request)
{
NameValueCollection queryCollection = SplitNameValuePairs(request);
string[] deatils = GetTextParameter(queryCollection);
if (deatils != null)
{
_rquestedEmpUserId = Convert.ToInt64(deatils[0]);
int CurrentEmpUserId = Client.DataService.GetEmpUserId(System.Environment.UserName);
if (CurrentEmpUserId == _rquestedEmpUserId)
{
onDemandScreenShot(Convert.ToInt64(deatils[1]), new Guid(deatils[2]));
}
}
}
有没有办法如果我发送特定系统的IP地址，那么它会请求同一系统而不是循环遍历所有系统？
*****来自桌面应用程序的代码******
public void Start(string url)
{
if (!HttpListener.IsSupported)
{
MessageBox.Show("Windows XP SP2 or Server 2003 is required.", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
try
{
mListener = new HttpListener();
// Add the prefix.
mListener.Prefixes.Add(url);
mListener.Start();
mListener.BeginGetContext(new AsyncCallback(this.ProcessRequest), null);
}
catch (Exception e)
{
MessageBox.Show(string.Format("Unable to start the web server.\n\n{0}", e.Message), Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
public void End()
{
if (mListener != null)
{
HttpListener listener = mListener;
mListener = null;
listener.Close();
}
}
public void AddCommand(HttpCommand command)
{
Debug.Assert(!mCommands.ContainsKey(command.Name));
mCommands[command.Name] = command;
}
public void AddResourceLocator(ResourceLocator locator)
{
foreach (string extension in locator.Extensions)
{
Debug.Assert(!mResourceLocators.ContainsKey(extension));
mResourceLocators[extension] = locator;
}
}
public void ProcessRequest(IAsyncResult result)
{
if (mListener == null)
{
return; // Listener is has been closed
}
// Call EndGetContext to complete the asynchronous operation.
HttpListenerContext context = mListener.EndGetContext(result);
try
{
DispatchCommand(context);
}
catch (Exception e)
{
MessageBox.Show(string.Format("Command failed.\n\n{0}", e.Message), Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
mListener.BeginGetContext(new AsyncCallback(this.ProcessRequest), null);
}
}
private void DispatchCommand(HttpListenerContext context)
{
HttpListenerRequest request = context.Request;
// Inform listeners that a request has been received.
// Only send up to 240 characters of the URL
const int MaxNotifyRequestLength = 240;
string unescapedUrl = request.RawUrl;
string notifyRequest = unescapedUrl.Substring(0, Math.Min(MaxNotifyRequestLength, unescapedUrl.Length));
if (request.RawUrl.Length > notifyRequest.Length)
{
notifyRequest += "..."; // Indicate the URL has been truncated.
}
OnRequestReceived(notifyRequest);
string queryString = string.Empty;
int urlEndPos = request.RawUrl.IndexOf('?');
if (request.HttpMethod == "GET")
{
if (urlEndPos != -1 && urlEndPos < request.RawUrl.Length - 1)
{
queryString = request.RawUrl.Substring(urlEndPos + 1);
}
}
else
{
queryString = GetQueryStringFromPostData(request);
}
// Split query string args into name/value pairs
NameValueCollection queryCollection = SplitNameValuePairs(queryString);
HttpListenerResponse response = context.Response;
response.ContentType = "text/html";
response.ContentLength64 = 0;
System.IO.Stream output = response.OutputStream;
// Extract a lowercase URL that doesn't include the query string.
string url = urlEndPos != -1 ? request.RawUrl.Substring(0, urlEndPos) : request.RawUrl;
url = url.Trim(new char[] { '/' });
url = url.ToLower();
// If it's a request for our dummy gif, send the dummy
// gif image as a response and then process the actual command
if (url.EndsWith("/dummy.gif"))
{
// Remove /dummy.gif from the url
url = url.Substring(0, url.Length - 10);
// Send the gif image
response.ContentType = "img/gif";
response.ContentLength64 = mDummyGif.Length;
output.Write(mDummyGif, 0, mDummyGif.Length);
}
// If the url has an extension (e.g. .png) then the
// request is for a file (e.g. an image), so see if
// a ResourceLocator is registered to handle this extension.
string extension = Path.GetExtension(url);
bool foundResource = false;
if (!string.IsNullOrEmpty(extension))
{
extension = extension.Substring(1);
ResourceLocator locator;
if (mResourceLocators.TryGetValue(extension, out locator))
{
locator.OutputResource(Path.GetFileNameWithoutExtension(url), extension, context);
foundResource = true;
}
}
// Not a request for a resource, must be a command
if (!foundResource)
{
HttpCommand command;
if (mCommands.TryGetValue("SpeakText", out command))
{
command.Execute(queryCollection, context);
}
}
// You must close the output stream.
output.Close();
}
这是Web应用程序上的Capture Link
<a href='javascript:var server="localhost:60024/SMARTer";var maxreqlength=1500;var EmpUserID="68675";if(EmpUserID){_bufferText(EmpUserID);_speakText()}void 0;function _formatCommand(b,a){return"http://"+server+"/"+b+"/dummy.gif"+a+"×tamp="+new Date().getTime()}function _speakText(){var a=new Image(1,1);a.onerror=function(){_showerror()};a.src=_formatCommand("speaktext","?source="+document.URL)}function _bufferText(f){var c="true";var b=Math.floor((f.length+maxreqlength-1)/maxreqlength);for(var d=0;d<b;d++){var g=d*maxreqlength;var a=Math.min(f.length,g+maxreqlength);var e=new Image(1,1);e.onerror=function(){_showerror()};e.src=_formatCommand("buffertext","?totalreqs="+b+"&req="+(d+1)+"&EmpUserID="+f.substring(g,a)+"&clear="+c);c="false"}}function _showerror(){alert("Server is not running.")}'>Capture</a>
正如您所看到的，我们在链接中提到了EmpUserID，我们想要截取屏幕截图。
在桌面应用程序的web.config文件中，我们添加一个键来监听该链接：
<add key="ScreenCaptureUrl" value="http://localhost:60024/SMARTer/" />