测试过程中发现文章中提供的代码存在兼容性问题，这源于一次偶然性的测试，当时用的是HP和SIEMENS的PDA进行测试，发现SIEMENS中当获取OEM信息时抛出异常，尝试性的进行了修改，居然解决了问题。具体的注释在代码中有详细的说明。
鉴于有些PDA程序被要求在PC上面兼容运行，这也是客户的一个需求。在此对文章中的代码进行了改进。文章中的代码原本被设计为在NETCF中运行，且使用了PINVOKE调用PDA中的相关底层函数，此代码如果在PC中运行，将产生不可预料的结果。由于当在PC上运行时，实际上是由.NET Framework的完整版本在执行代码，已经失去了对目标平台检测的意义。所以为了防止不可预料的结果出现，对相关代码做了修改。这一功能的实现是通过一个新添加的方法IsWinCE来实现的。该方法也可以向调用方提供必要的信息，作为检测实际执行代码的Framework的方法，具体参见源代码。
最终版本提供的检测功能：
- IsWinCE ()
- IsEmulator ()
- IsSmartPhone ()
- IsPockPC ()
- IsTouchScreen ()
源码如下：
using System;
using System.IO;
using Microsoft.Win32;
using System.Runtime.InteropServices;
using System.Text;
namespace PlatformDetection
{
internal class PInvoke
{
[DllImport("Coredll.dll", EntryPoint = "SystemParametersInfoW", CharSet = CharSet.Unicode)]
static extern int SystemParametersInfo4Strings(uint uiAction, uint uiParam, StringBuilder pvParam, uint fWinIni);
const int MAX_PATH = 260;
[DllImport("Coredll.dll")]
static extern int SHGetSpecialFolderPath(IntPtr hwndOwner, StringBuilder lpszPath, int nFolder, int fCreate);
public enum SystemParametersInfoActions : uint
{
SPI_GETPLATFORMTYPE = 257, // this is used elsewhere for Smartphone/PocketPC detection
SPI_GETOEMINFO = 258,
}
public static string GetOemInfo()
{
//10/26/2006 wangyun Change from 50 to 100, as it doesn't work on "FUJITSU SIEMENS COMPUTERS Pocket LOOX"
StringBuilder oemInfo = new StringBuilder(100);
if (SystemParametersInfo4Strings((uint)SystemParametersInfoActions.SPI_GETOEMINFO,
(uint)oemInfo.Capacity, oemInfo, 0) == 0)
throw new Exception("Error getting OEM info.");
return oemInfo.ToString();
}
public static string GetPlatformType()
{
//10/26/2006 wangyun Change from 50 to 100 to avoid the possible bug as above
StringBuilder platformType = new StringBuilder(100);
if (SystemParametersInfo4Strings((uint)SystemParametersInfoActions.SPI_GETPLATFORMTYPE,
(uint)platformType.Capacity, platformType, 0) == 0)
throw new Exception("Error getting platform type.");
return platformType.ToString();
}
public enum SpecialFolders : int
{
CSIDL_WINDOWS = 0x0024,
}
public static string GetSpecialFolder(SpecialFolders specialFolder)
{
StringBuilder path = new StringBuilder(MAX_PATH);
if (SHGetSpecialFolderPath(IntPtr.Zero, path, (int)specialFolder, 0) == 0)
throw new Exception("Error getting Windows path.");
return path.ToString();
}
}
public class PlatformDetection
{
private const string MicrosoftEmulatorOemValue = "Microsoft DeviceEmulator";
//10/26/2006 wangyun To effect compatibility between PC and PDA devices
public static bool IsWinCE()
{
return System.Environment.OSVersion.Platform == PlatformID.WinCE;
}
public static bool IsEmulator()
{
if (IsWinCE())
return PInvoke.GetOemInfo() == MicrosoftEmulatorOemValue;
else
return false;
}
public static bool IsSmartphone()
{
if (IsWinCE())
return PInvoke.GetPlatformType() == "SmartPhone";
else
return false;
}
public static bool IsPocketPC()
{
if (IsWinCE())
return PInvoke.GetPlatformType() == "PocketPC";
else
return false;
}
public static bool IsTouchScreen()
{
if (IsWinCE())
{
string driverFileName = Registry.GetValue(@"HKEY_LOCAL_MACHINE\Hardware\DeviceMap\Touch",
"DriverName", "touch.dll").ToString();
string windowsFolder = PInvoke.GetSpecialFolder(PInvoke.SpecialFolders.CSIDL_WINDOWS);
string driverPath = Path.Combine(windowsFolder, driverFileName);
bool driverExists = File.Exists(driverPath);
return
driverExists &&
// Windows Mobile 5.0 Smartphone emulator and earlier has a driver, but no touch screen.
!(IsSmartphone() && IsEmulator() && Environment.OSVersion.Version.Major < 6);
}
else
return false;
}
}
}
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