'VB
Dim temp As Single = 3.6F
Dim rounded1 As Integer = Fix(temp + .5F)
Dim rounded2 As Integer = Convert.ToInt32(temp)
7.41. Why does Control.Invoke take so long when a modal dialog is displayed?
There is a known bug with using Control.Invoke while a modal dialog is displayed through ShowDialog. Download the latest .NET Compact Framework Service Pack to fix this:
The latest platform updates and .NET Compact Framework service packs are available at:
http://msdn.microsoft.com/mobility/downloads/default.aspx
7.42. Is there a way to retrieve the culture information of an Assembly?
Culture information can be retrieved through Reflection: //C#
using System.Reflection;
using System.Globalization;
Assembly asm = Assembly.GetExecutingAssembly();
CultureInfo ci = asm.GetName().CultureInfo;
'VB
Imports System.Reflection
Imports System.Globalization
Dim asm As Assembly = Assembly.GetExecutingAssembly()
Dim ci As CultureInfo = asm.GetName().CultureInfo
8.通讯和Web服务
8.1. 如何通过TCP Socket向桌面机发送数据？
请查看本问答的"10.5. 写一个捕捉Pocket PC签名的程序. " 部分。
8.2. 为什么不能访问本机上的Web服务？
不要在设备上使用localhost来引用Web服务，因为对于设备来说localhost就是运行应用程序所在的设备，就是设备它本身。您应该使用机器名或IP地址来引用Web服务。
8.3. 如何在微软.net精简框架上调用Web服务
这篇文章向您演示了如何从智能设备上，通过.net精简框架同步和异步调用Web服务：
http://msdn.microsoft.com/library/en-us/dnnetcomp/html/netcfwebservices.asp
8.4. 如何通过代理服务器提交HTTP GET申请？
通过或不通过特定的代理服务器提交HTTP GET请求。
使用StreamReader读取返回的HTML，并转成字符数组。然后把返回的值显示在ListBox中，如以下的屏幕截图所示：
http://samples.gotdotnet.com/quickstart/CompactFramework/doc/httpgetwithproxy.aspx
8.5. 如何使用Web服务？
这篇快速入门教程，描述了如何使用提供了简单数学计算的Web服务(这个数学计算的Web服务在.net框架的快速入门中有说明，标题是"Write a Simple Web service,")。这个快速入门教程提供了一个Web服务的客户端应用：
http://samples.gotdotnet.com/quickstart/CompactFramework/doc/xmlwebservice.aspx
8.6. 如何使用MapPoint3.0得到地图？
这篇快速入门描述了如何使用MapPoint的Web服务，编程实现在PocketPC上获得特定位置的程序，如以下屏幕截图所示：
http://samples.gotdotnet.com/quickstart/CompactFramework/doc/mappointfindmap.aspx
8.7. 如何使用MapPoint3.0获得地图和方向？
这篇快速入门教程描述了如何使用MapPoint的Web服务，在PocketPC上获得特定位置的地图方向，如以下屏幕截图所示：
http://samples.gotdotnet.com/quickstart/CompactFramework/doc/mappointdirections.aspx
8.8. Is NTLM authentication supported by the .NET Compact Framework?
Using Digest authentication instead of Basic or NTLM authentication is the recommended solution. Digest authentication is supported by the .NET Compact Framework.
8.9. When using blocking Sockets, why does Send throw an InvalidOperationException when blocking is set to false?
There is a known issue with setting Blocking to false on a blocking socket. There are three paradigms when programming with sockets (both managed and native) and it is strongly recommended that developers use asynchronous I/O functions as a solution to this problem. Select is very inefficient in managed code, and the cost of the regular case exception is also high. The three paradigms are detailed below, with the last being the preferred method.
Use blocking calls on blocking sockets (i.e. send(), recv(), etc). This is the simplest method, and probably the most commonly used. The functions perform their operation synchronously, tying up the currently executing thread. This is most acceptable for clients, and multithreaded servers (Microsoft does not recommend using one thread per client because threads are very expensive on Windows). Note that though the operations may block for an unspecified period of time (i.e. until the operation can be completed), they will most often complete immediately.
Use non-blocking sockets in conjunction with select or poll. Use the same "blocking" functions, but put the socket in a special mode that prohibits it from blocking. In the cases when the function would block, it returns an error code (in managed code, this throws an exception). You can then use poll or select to wait until a point in time at which an operation would complete (select allows you to manage more than one socket, so you can handle multiple clients on only one thread), and then perform the operation. At the time these calls were created, there were no threads in operating systems, so this was the only way to do things. Using this mechanism has by far the absolute worst performance you could possibly get from socket programming. This problem is exacerbated in managed code, since you now expect an exception to be thrown, which is an even bigger performance hit.
Use asynchronous I/O functions on the socket. This is your best all around solution. It allows you to perform operations asynchronously, and you get notified by callbacks. In general, the performance is better than using non-blocking I/O with select, and this is the recommendation for how to do things (at least, in native code).
8.10. How do I create an http-server?