A day in the life of...

A customer requested that instead of my NumericUpDown controls silently capping the input value within the Minimum..Maximum range it instead showed an error message telling the user their input is incorrect and that they need to alter it. I was a bit annoyed to see that NumericUpDown.Validating is never called on the compact framework, in addition there was no way to get the input value and either accept or reject it before it is applied to its data bindings. There's an article here which shows how to implement auto-select text when the NumericUpDown receives focus and I have been using it since Feb 2006. I decided to extend upon the techniques within it to implement the Validating event. My goal was to fire the Validating event before the value is applied to all data-bindings, but also to allow the programmer to read NumericUpDown.Value in order to determine the new value. To do this I had to replace the WndProc of the control so that I could handle the WM_UPDOWN_NOTIFYVALUECH

I recently released an update to some software and a bug slipped through the net. It introduced some odd behaviour with a control named SmartGrid. After some testing I was able to determine that it wasn't my fault and that I could reproduce a bug in SmartGrid. I hate bugs in other people's source code, I can't fix it, I am at their complete mercy. Thankfully the Resco support was amazing! I posted on their forums and immediately someone sent me instructions on where to send my project. The next morning I was disappointed to see an email saying that the project worked fine. I posted again and almost immediately someone had offered to chat on skype. We did that for a while, both confused by the problem. We then went on to use Remote Assistance so that he could observe my bug which he wasn't experiencing. In the end the problem was very confusing. I had Version A of the DLL in which the error occurred. I upgraded to the latest version (B) and it still occurred. T

This has been driving me mad for hours now! Whenever I run my PocketPC compact framework app I cannot debug it! None of the breakpoints will stop, each breakpoint just shows as an empty circle instead of a solid one. So, what was the solution? I tried deleting all PDB files on my hard disk but that didn't do it. In the end manually deleting all of the files previously deployed to my PPC did the trick. Maybe VS couldn't overwrite them or something? No idea, but at least it works now :-)

I've had no end of grief trying to print a PCX to a Zebra Printer using the CPCL printer language. Silly me, didn't notice the EG command (expanded graphics) so there was no need to convert my BMP to a PCX and then struggle with binary data. I still had a bit of grief working out how to print using the EG command because the documentation is quite frankly crap. The expected command format is EG {WidthInBytes} {HeightInPixels} {XPos} {YPos} {Data}\r\n The printer expects a 1 bit pixel matrix. So if pixel(0, 0) is set you will set "80" in the data. If pixel(0, 0) is set and pixel (7, 0) is also set you would sent "81". Basically what you need to do is to read each set of 8 horizontal pixels and then use bit operations to create a byte value 0..255, and then output this as hex 00..FF. Here's the routine :-) public void DrawBitmap(Bitmap bmp, int xPosition, int yPosition) { if (bmp == null) throw new ArgumentNullException("bmp");

We use wireless printing through a COM port over BlueTooth. Having BlueTooth on all of the time can contribute towards energy consumption and cause the battery life on the Pocket PC to deplete faster. Now I disable BT when the application starts, and then re-enable it to print and disable it immediately afters. This adds about 1 second to each print job but it should save the battery power. [DllImport("BthUtil.dll")] private static extern int BthGetMode(out BlueToothRadioMode dwMode); [DllImport("BthUtil.dll")] private static extern int BthSetMode(BlueToothRadioMode dwMode); public static BlueToothRadioMode BlueToothRadioMode { get { BlueToothRadioMode result; BthGetMode(out result); return result; } set { if (value != BlueToothRadioMode) BthSetMode(value); } }

My compact framework application imports XML into a local database. As there is so much data to import this can take up to an hour. During development there were no problems with this, but of course during development the Pocket PC is docked in its cradle which provides it with power. When a Pocket PC is removed from its cradle it manages power differently, just like an unplugged laptop. So every five minutes the Pocket PC would hibernate and the user would have to turn it back on in order for the import to continue. During an hour the user would have to do this approximately twelve times. How annoying, and dangerous too if the employee is driving to their first job. Anyway, I found the following very useful code on the web and thought I'd point it out as it was so useful! public class Device { #region Device sleep support [DllImport("CoreDll.dll")] public static extern void SystemIdleTimerReset(); private static int DisableSleepCallsCount = 0; private static Sy

I recently developed a simple support application that allows users on a PC to provide a one-off security number to a Pocket PC user and when entered the PPC will perform a specific support function. I used the same class to generate these security codes in both the desktop and compact framework applications, tested it quite thoroughly and it all seemed to work fine. However once deployed it became evident that the codes provided by our support department were being rejected by the PPC as invalid. So what went wrong? Seeing as the same class was used for both applications I thought it would be okay to test the encoding/decoding of command numbers on only a single platform, and this was my mistake! The routines use string.GetHashCode() to add a checksum to the end of the security codes just to prevent the user from performing actions without authorisation. For reasons I cannot imagine the implementation of string.GetHashCode() is different in the compact framework from the one in t

I've been writing an app for the compact framework for some months now. It's quite a complicated app that includes an object persistence framework, a task oriented application layer and a loosely coupled GUI which is generated through factories (the app only has 1 form, but lots of user controls + factories). The app has been experiencing apparently random OutOfMemoryExceptions, no matter how hard I have tried I have found it impossible to reproduce one of these errors. I have spent quite some time really optimising the memory useage of my OPF so that it works on the bare minimum of memory yet still operates quickly enough (and I'm very pleased with its performance too). However, the OOM exceptions persisted! I wrote a logging tool which records the last X actions the user performs, when an unexpected exception occurs this log is written to disk along with a stack trace of the exception. I noticed that the top of the stack trace always read... at Microsoft.AGL.Com