In The Hand Ltd

Category: NETCF

  • Potted history (and glimpse into the future) of the .NET Compact Framework

    Mike Zintel has posted a description of how the .NET Compact Framework got to where it is today, and where the team are headed in v2.0 and beyond.


    Key lessons learned by the team were in performance, interop and a few bloopers like the infamous DateTimePicker – the control which should never have been left out. The good news is that all these areas are receiving attention for v2.0.


    A focus for v3.0 will be managing transient networks – being able to seamlessly use a connection as and when available, based on emerging WS-* standards. We will see some improvements in this area before v3.0 as the Windows Mobile team have already announced the Notifications Broker for their next version which will support events on key system changes, however this won’t be available to other Windows CE based platforms. The problems faced are not just in choosing and activating the most appropriate connection, but handling situations where the connection is lost part way through a process, a real problem when your devices are constantly on the move, in and out of network coverage.


    My personal wishlist for v3.0 would add more support for location and context awareness, so that apps can be a little more smart to react to changes not just in network connectivity but also changing usage profiles such as sound and appearance for different locations and times.


    Once you’ve read Mike’s article you can check out some of his wonderful photographs too at http://www.zintel.net/.


     

  • More details on Generics and Reflection for .NETCF v2.0

    Nazim Lala from the .NET Compact Framework team has posted further details on the generics support in .NETCF v2.0 specifically the Reflection functionality available and how it differs from the full framework implementation.

  • Bluetooth Build 50115

    I’ve posted an updated build of the Bluetooth library here. It adds full support for the desktop, improved class-of-device and other properties.


    The sample app is now supplied in Pocket Pc, Smartphone and Desktop versions which all talk to each other.

  • .NETCF Service Pack 3 is out – Go Get It!

    .NETCF SP3 Redistributable can be downloaded from here:-


    http://www.microsoft.com/downloads/details.aspx?amp;displaylang=en&familyid=a5a02311-194b-4c00-b445-f92bec03032f&displaylang=en


    List of fixes grabbed from the above page:-


    Fixed Issues:
    – Transitions between managed and native code can cause memory leaks on ARM platforms.
    – A NullReferenceException is thrown when a Web Method returns an empty array using the xsi:Nil attribute.
    – Modifying the SoapClientMessage.ContentType property does not modify the Http requests ContentType header.
    – Stack corruption can occur on SH, MIPS and x86 platforms when local variables are created but never used.
    – Invoking a multicase delegate from a catch handler throws a MissingMethodException on SH, MIPS and x86 platforms.
    – Command line arguments containing double byte characters are truncated to a single byte.
    – An ObjectDisposedException is thrown when a asynchronous web request is aborted before the response is received.
    – Invoke on a disposed control hangs the application.
    – Any array containing one or more elements is not sent to the Web Service correctly.
    – An application may hang when invoking a Web Method that uses multiple XmlElementAttributes on a single argument, member or property.
    – Memory corruption can occur on devices that have the native security model enabled and both .NET CF V1 SP3 and a pre-release version of .NET CF V2 installed.
    – Deadlocks can occur when running under severe resource constraints.
    – Tool Bar’s on Windows Mobile 2003 SE no longer lose their images when removed from the form.
    – An uncatchable ObjectDisposedException is thrown when the server closes the socket connection.
    – Setting the Minimum and Maximum properties of a progressbar no longer crashes the application.
    – Unexpected exception while adding an image to an imagelist on an Hx4700 and hx4705.
    – Data Misalignment occurs on Decimal fields in MIPSIV devices.

  • GetEntryAssembly for .NETCF

    If your application contains multiple levels of DLL files, you may want to determine the name and path of the original calling executable. On the desktop you can use Assembly.GetEntryAssembly() but this is not available in the Compact Framework. I have added an equivalent to the SDF code to work in just the same way, using Platform Invoke. It uses the GetModuleFileName API which when passed IntPtr.Zero for the module handle, returns the path of the calling exe. Assembly.LoadFrom is then used to return the Assembly object corresponding to this path. Since the exe is already loaded this will not increase the overhead of your application. From the returned Assembly object you can determine the Path, Version etc as required.


    The full code for AssemblyEx is available in the online Source Browser, and will be built into a future SDF release.

  • Rudolph the Bluetoothed Reindeer

    I’ve uploaded a new release of the Bluetooth library which adds the key feature of hosting services over bluetooth. This now allows two-way communications between devices and to demonstrate how this works I’ve included a sample Bluetooth Chat application. This registers a custom bluetooth profile and listens for incoming connections, and creates outgoing connections using this service identifier to other devices. In this way it only communicates with other devices exposing this service and wont interfere with any other applications using Bluetooth.


    Thanks go out to Wei-Meng Lee for giving permission to base the sample on his previous IrDA chat application available with this MSDN article. The Bluetooth version works in a very similar way, with the exception of doing a device discovery when it first loads. An enhancement yet to be added is the ability to periodically discover in a background thread. From the app screen select the target device which must also be running the software and Bluetooth must be Discoverable. Then type your message and click send and it will appear onscreen on the other device. In the below example I had a brief conversation with Santa who was half-way up a chimney at the time – such is the versatility of Bluetooth 🙂

    Bluetooth Chat

    The ZIP file below includes the Bluetooth library project and compiled output, and the BTChat sample project. As I get time to do more work on the library I’ll post some other examples, and include versions for other platforms e.g. Smartphone and XP.


    Known issues:-



    • Hosting services doesn’t yet work on XP (some of the structures are slightly different so this requires a little more work)
    • BluetoothClient.RemoteDeviceName doesn’t work so you can’t retrieve the device name from an open connection (Device names work correctly during discovery on both Windows CE and XP)
    • BluetoothSerialPort (For emulating a COM port) is not fully tested and probably doesn’t work – SerialPortProfile connections work great using sockets (BluetoothClient).

    Requirements:-



    • SDF v1.2
    • Windows CE Device or Windows XP computer using the Microsoft Bluetooth stack (Sorry but Widcomm is not supported).

    Download:-


    Downloads


     


    If you have any comments or questions please drop me an email. For now all that remains is for me to wish you a Very Merry Christmas!

  • New in .NETCF v2.0

    Jono posted a link to a new section in the online Beta documentation at MSDN which describes in some detail whats new in v2.0 of the Compact Framework. This includes new framework features and a list by namespace of the new classes introduced in v2.0.


     

  • Online Bluetooth code updated

    There were some recent enquries on the OpenNETCF Forums about the current Bluetooth code. It seems I had refreshed the website with some development code which would only work if a couple of items were commented out. This is because these classes (Sdp related) are still under development and require COM interop and are currently built against InTheHand.Interop.dll which does COM interop with no native DLL required, and is used in my PocketOutlook and ADOCE products.


    So I’ve updated the code online and attached a .zip of the project below which will build successfully against the v1.2 SDF (and the compiled dll is included in the bin folder). Documentation is in the online library at http://32feet.net/library/


    I’m working on a sample application to accompany the library, but it’s been tested with a Bluetooth GPS unit and a Jabra headset successfully (Before you ask it only uses the control functionality of the headset, not the audio stream). But you can programmatically make the headset ring and capture the event when the user presses the answer button. Not terribly exciting but an interesting start, I guess I need some more unusual Bluetooth devices to test against.


    What isn’t working in this release is the ability to host a service and allow other devices to discover it, since this requires some of the ongoing Sdp work. Once this is in place you will be able to do data transfer between devices which is when the fun will really begin!


    Also bear in mind this is designed to work only with devices with the Microsoft Bluetooth stack, for example HTC Phone Edition devices and most Smartphone 2003 models.


    Downloads

  • Forms Anywhere built around OpenNETCF Smart Device Framework

    Via Jono’s Blog:-


    ‘Forms Anywhere is an attempt to provide a development platform for data capture using the Pocket PC. It handles all data collection tasks from creation to capture, all that is needed on the back end is the code to integrate your application.’


    The code for Jim Lavin’s Forms Anywhere is available in a GotDotNet workspace. The project uses OpenNETCF’s Smart Device Framework for missing controls such as the DateTimePicker and the Desktop Communications library to implement desktop synchronisation. An impressive project, well worth a look.

  • Using OpenNETCF.Phone.Sms

    Dag König has posted an example to his blog showing how to add Sms sending to your application using the OpenNETCF.Phone.Sms class and just 4 lines of code – check it out.