Zorn Software

After creating an ASP.NET web application in Visual Studio, to host it in a freshly installed IIS 7.5, you need to do two things that are not immediately obvious:

1. Create a new app pool or change the default app pool to target .NET 4 (see IIS->Application Pools).
2. Run this from the command line:
   %windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -i

MSDN has more info on aspnet_regiis command line options here.
Just putting this on my blog so I can remember this magic command line.

If you record videos of your automated acceptance tests (we are using CamStudio), an excellent addition is to install the free Prism HUD utility. This will give you on-screen (but transparent to mouse actions) CPU / disk / network and memory statistics which can be very useful when reviewing these videos. It appears to be the only application that allows reporting of metrics of any process that exceeds a certain (configurable) delta, or is over a certain (configurable) threshold. This means you get much more useful information than just a summary metric (e.g. total CPU utilization), but you don’t clutter your screen with the metrics for all processes, just those ‘that matter’ at any point in time, automatically!!

Go get it here.

I’ve hand-collected > 100 great programming quotes and stuffed them in a tiny console application, which, when run, will randomly print one to the console. Use it as a footer for your nightly build email, or anywhere you have some drabby generated document / email.

Also can be used if you are just bored on a Friday afternoon.

Download it here.

Creating a custom view/control in Android is fairly simple – here are the steps I used:

1. Create a new class which extends from the ‘View’ abstract base class. E.g.
   public class MyCustomControl extends View
2. Provide constructor overloads for ALL of the following prototypes, where initView() is a method in which you perform initialization of things such as Paint objects:

   public MyCustomControl(Context context)
   	{
   		super(context);
   		initView();
   	}
   
   	public MyCustomControl(Context context, AttributeSet attrs)
   	{
   		super(context, attrs);
   		initView();
   	}
   
   	public MyCustomControl(Context context, AttributeSet attrs, int defStyle)
   	{
   		super(context, attrs, defStyle);
   		initView();
   	}
   

3. Override onMeasure() in order to scale your control to the parent drawing area, such as shown in this good example.
4. Do your canvas drawing operations in onDraw on the supplied Canvas object.
5. Instantiate your custom view in a layout xml file (e.g. main.xml), for example:

   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:orientation="vertical"
       android:layout_width="fill_parent"
       android:layout_height="fill_parent"
       >
   	<com.android.samples.MyCustomControl
   		android:id="@+id/myCustomControl"
       	android:layout_width="fill_parent"
       	android:layout_height="fill_parent"
       />
   </LinearLayout>

I found that if I didn’t add the 2nd and 3rd constructors, I got an exception when calling setContentView(R.layout.main) from onCreate() of the main Activity. You can instead construct an instance of the view manually in onCreate() of the main Activity, and then call setContentView(yourCustomViewInstance) if you don’t want to use XML layout.

Our nightly build was taking > 30 minutes to delete our source tree before getting latest (Windows is not quick to delete a large number of small files), which was comparable to the time taken to actually compile the source. There are stackoverflow and superuser articles that discuss the fastest way to do deletes, however there’s no magic solution. If you find you are regularly needing to delete large amounts of files (e.g. as part of the nightly build process), your best option is to create a new partition on your HDD (or install a new HDD) and store all the files you will be deleting on there. Then you can erase them all in about 2 seconds by doing a quick format of the drive! The only trick is how to programatically format a drive, since there is no (documented) API for this in Windows. There’s Win32_Volume.Format (WMI) but it’s only available in server OSs, and then there’s SHFormatDrive, which shows a dialog.

However, provided your partition (in this case Z:) has no label, you can do this:

echo Y | format Z: /FS:NTFS /X /Q
An inferior alternative to this is to use a VBScript that uses SendKeys like this:

set WshShell = CreateObject("WScript.Shell")
wshShell.run "c:\windows\system32\format.com Z: /FS:NTFS /V:QuickWipeDrive /X /Q"
wscript.sleep 1000
wshshell.sendkeys "QuickWipeDrive" & "{ENTER}"
wscript.sleep 1000
wshshell.sendkeys "Y" & "{ENTER}"
wscript.sleep 5000

The downside of this script is that it will only work when the computer is not locked since SendKeys requires a console session that is logged in an active.

Since the audio revamp in Windows Vista, many things that were possible to do in code in the past (i.e. XP) are now difficult or impossible. One of those tasks that was easy in XP was setting the default audio device for playback. In XP this just required a registry change, but in Vista & Windows 7, Microsoft decided that developers should not have access to change the default audio device, so they locked down the registry and provided no documented API to achieve this. Their reasoning was that if two programs both wanted to set the default audio device, they would end up fighting each other for it, which of course is bad. But I believe this is a very short-sighted decision, since there are plenty of legitimate cases where a program needs to do this. These are discussed on this amazingly long-living thread (started in 2006 and still going).

The end result is that, no thanks to Microsoft, we finally have a way to do this, and I’ve created a console application in case others would like to control this as well:

Usage: SetDefaultAudioDevice.exe [deviceID] [role]
Where:
[deviceID] is a GUID including braces
[role] is either ‘console’, ‘multimedia’ or ‘communications’.

Example: SetDefaultAudioDevice {24dfc80a-680f-4748-8627-c340cb14f187} multimedia

Your audio device IDs can be found in the registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\MMDevices\Audio\Render.

Feel free to download this utility here, source code is in my SVN repo.

Thank-you to EreTIk and Jonny Best and everyone else on the above forum post!

After manually merging a set of source changes to a .csproj file, my project would no longer build, giving this error:

Common.targets(588,5): error RG1000: Unknown build error, ‘An item with the same key has already been added.’

Not particularly helpful, especially if there are a large number of changes in the .csproj file. To get more information in such a case, in VS2010 you can go to Tools->Options->Projects and Solutions->Build and Run and set the MSBuild output verbosity to ‘Diagnostic’. After attempting to build again, the error now becomes much more useful:

Error 2 The item “Views\FeedbackView.xaml.cs” was specified more than once in the “Sources” parameter. Duplicate items are not supported by the “Sources” parameter. C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.CSharp.targets 160 9 MyCompany.MyProduct.WebClient

Interestingly, after I reset the verbosity level back to Minimal (without making any code changes), the more detailed error still appeared. Weird.

If you install IIS on a 64-bit operating system, you may get the following error when navigating to your website locally:

Could not load file or assembly ‘Interop.COMAdmin’ or one of its dependencies. An attempt was made to load a program with an incorrect format.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.BadImageFormatException: Could not load file or assembly ‘Interop.COMAdmin’ or one of its dependencies. An attempt was made to load a program with an incorrect format.

The clue here is the BadImageFormatException, which hints that this is a 32/64 bit issue. To fix it, in IIS Services Manager, go to Application Pools, select the application pool under which your website/application is running, and choose ‘Advanced Settings’. Change ‘Enable 32-bit Applications’ from False (the default) to True. Recycle your app pool, and reload your browser page, no more error!

I bought a Bluetooth Bee from Seeed Studios, which is an SPP (Serial Port Profile) bluetooth device, with the intention of writing an app for Android that communicates with a remote data logger. Unfortunately, it turns out that there’s a bug in the BroadComm bluetooth stack that is used by most Android phone manufacturers (LG, HTC, Samsung are affected, but not the Google Nexus phones) that prevents discovery to this and all other bluetooth devices that report their Class of Device (CoD) code as 0×00. This is the case for many SPP bluetooth devices, and SPP is probably the most common bluetooth profile (at least it’s the most basic – just straight serial comms) so this bug is pretty nasty.

Basically, if you perform a scan for devices, your SPP device will not show up, and in the logs you will see:

ERROR/DTUN_HCID4(663): Device [00:18:E4:0C:6E:CA] class is 0×00 – skip it.

The code for the Broadcom bluetooth stack is open source, so the bug is plain for all to see here. The bug has been reported on StackOverflow and elsewhere.

Until Broadcom and/or all users of their bluetooth stack fix this issue (by simply removing the IF block that skips devices whose CoD is 0×00), the only way to connect to your SPP device from Android is to read the log files, looking for the above error, extract the device address, and manually initiate a connection in code. After this, your SPP device will appear along with all your other bluetooth devices in the bluetooth settings page on your phone, and you can successfully communicate using the bluetooth API provided by Google.

I have written a re-usable class that implements this workaround, which you can download from here.

How to use (from your Activity class):

(new BluetoothClassZeroDiscoveryTask(
    this,
    new BluetoothDiscoveryCallback())).execute();

Where BluetoothDiscoveryCallback is a class defined e.g. in your Activity. The call method will be called after the discovery task completes, and is passed the complete list of paired bluetooth devices, including those that are undiscoverable due to the above bug.

private class BluetoothDiscoveryCallback
    implements Action<ArrayList<BluetoothDevice>>
{
	public void call(ArrayList<BluetoothDevice> devices)
	{
		// Now you have the list of ALL available devices,
		// including those that report class 0x00.
	}
}

// Java equivalent of the built-in Action from C#.
public interface Action<T>
{
	void call(T target);
}

You’ll also need to add READ_LOGS permission to your manifest file:

<uses-permission android:name="android.permission.READ_LOGS" />

Feel free to suggest improvements to the code, I’m new to Android and haven’t done Java in ages

P.S. Hassle your phone manufacturer to fix this bug so this workaround is not needed!

Update: I have turned the above class into an app which I’ve made available in the Android Marketplace called Bluetooth Class Zero. It is a simple application which just enables pairing with bluetooth class zero devices without having to root & patch your phone. Screenshots:

After pressing “Start Discovery”, if any bluetooth class zero devices were found (but ignored), you will get the standard pairing dialog:

After entering the correct PIN code, your device will be listed alongside others in your bluetooth settings:

The app requires Android 2.1+. It’s been tested on the following phones:

The app is free to use, if you find it useful, feel free to make small donation

Google’s Picasa Photo Viewer is one of the best photo preview applications, it loads quickly, and is easy to exit. Unfortunately, Google introduced a bug recently that causes the PicasaPhotoViewer.exe process to remain in memory even after you close the application. Several posts on google forums and elsewhere have reported this:

Why does PicasaPhotoViewer.exe stay resident in memory
Multiple picasaphotoviewer.exe ghosts in Task Manager
Memory Loss from orphaned PhotoViewer Processes
PicasaPhotoViewer Process Doesn’t Terminate

This appears to only occur when you open a photo on a network location, such as a network drive. This is a pretty normal usage scenario, such as storage of photos on a RAID server or NAS, and is actually pretty nasty, because it means you can’t rename/delete/move any directory in which you viewed an image including any parent directory (due to the still-running PicasaPhotoViewer.exe locking the directory). It doesn’t take long for this to get seriously annoying when you find yourself having to open Process Explorer/Task Manager to kill off all the orphaned PicasaPhotoViewer.exe processes when you are working with directories.

Until Google fixes this, I solved this with a small C# application. It monitors for orphaned instances of PicasaPhotoViewer.exe (i.e. those that are running but have no window) and kills them. This is the complete code:

static void Main(string[] args)
{
   while (true)
   {
      var picasaProcesses =
         (from p in Process.GetProcessesByName("PicasaPhotoViewer")
          where p.MainWindowHandle == IntPtr.Zero && !p.HasExited
          select p);

      foreach (var process in picasaProcesses)
      {
         process.WaitForInputIdle();
         if (process.MainWindowHandle == IntPtr.Zero)
         {
            process.Kill();
            process.WaitForExit();
         }
      }

      Thread.Sleep(1000);
   }
}

Feel free to download the utility, and launch it on Windows startup using a logon script such as described here. Note: The program requires admin rights to run, so you can’t just place a shortcut to it in your ‘Startup’ folder if you are using Vista/7 with UAC switched on.

Update: Ok, it appears this issue has been fixed by Google in Picasa build > 117.38. Updating to the latest version (build 117.43 at the time of writing) fixed the issue for me, so my program should no longer be needed

Update 2: According to the comment below, the issue may still be occurring for some people. So I have made the program to fix this available for download again.