Friday, September 15, 2006

Platform detection I: How to detect that your app is running in the emulator

When you develop your Windows CE or Windows Mobile application in .NET Compact Framework, you probably do a lot of testing on the Microsoft Device Emulators for Smartphone and Pocket PC.  Here I describe how to detect whether your program is running on an emulator or a physical device.

Microsoft's Device Emulator gives itself away through a WinCE API called SystemParametersInfo when you pass in the argument SPI_GETOEMINFO.  We'll use this to check for the emulator.  When we detect something other than the Microsoft value, we must be running on a physical device. 

I use partial classes because in later posts in the Platform Detection series I'll add more to these classes.

using System;
using System.IO;
using System.Windows.Forms;
using Microsoft.Win32;
using System.Runtime.InteropServices;
using System.Text;

namespace PlatformDetection
{
internal partial class PInvoke
{
[DllImport("Coredll.dll", EntryPoint = "SystemParametersInfoW", CharSet = CharSet.Unicode)]
static extern int SystemParametersInfo4Strings(uint uiAction, uint uiParam, StringBuilder pvParam, uint fWinIni);

public enum SystemParametersInfoActions : uint
{
SPI_GETPLATFORMTYPE = 257, // this is used elsewhere for Smartphone/PocketPC detection
SPI_GETOEMINFO = 258,
}

public static string GetOemInfo()
{
StringBuilder oemInfo = new StringBuilder(50);
if (SystemParametersInfo4Strings((uint)SystemParametersInfoActions.SPI_GETOEMINFO,
(uint)oemInfo.Capacity, oemInfo, 0) == 0)
throw new Exception("Error getting OEM info.");
return oemInfo.ToString();
}

}
internal partial class PlatformDetection
{
private const string MicrosoftEmulatorOemValue = "Microsoft DeviceEmulator";
public static bool IsEmulator()
{
return PInvoke.GetOemInfo() == MicrosoftEmulatorOemValue;
}
}
class EmulatorProgram
{
static void Main(string[] args)
{
MessageBox.Show("Emulator: " + (PlatformDetection.IsEmulator() ? "Yes" : "No"));
}
}
}

This is the first post in a series of three on platform detection.  Coming up next: discerning between Smartphones and Pocket PCs.

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