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BatchCommand 'System.ArgumentNullException'

Dec 26, 2013 at 2:59 PM
Hi, i tested successfully your sample Under WPF (Microsoft channel tutorial).

I ported the sample to WinRT ; that's OK ; i added code in the manifest for USB and Bluetooth.

When i command the robot from the simulator : it's OK to go backward, forward but not right and left.

The code is different, cause a bachcommand is executed. On the first click on "right" or "left" button, i have an exception ; (after the move is executed)

"An exception of type 'System.ArgumentNullException' occurred in mscorlib.dll but was not handled in user code"

It seem that you have a dictinary and the value of the specified key is null...

Thanks for your great works !
Dec 26, 2013 at 5:12 PM
Can you provide the code you're attempting to run and/or more details on the error? This is not something we have experienced in our testing. Also, there is an official Samples package on the Downloads page which includes a fully working WinRT example.
Dec 31, 2013 at 9:51 PM
I have been having the same problem, I can send DirectCommands but not BatchCommands, I receive a System.ArgumentNullException for the BatchCommands even though they use the same parameters as the DirectCommands. I'm not exactly sure what it is trying to tell me is null, but something that I am finding interesting when attempting to execute BatchCommands is that they are being executed (at least in this case), and the error is being thrown on the SendCommandAsync() method. Does this mean that SendCommandAsync() is deleting something it shouldn't be? Does it mean I am not giving it something I should be? Any help would be appreciated. Thanks.
Dec 31, 2013 at 9:59 PM
I have a feeling you two are seeing what's fixed here:

https://legoev3.codeplex.com/SourceControl/changeset/fb35cfa4095158e3fe23e8a49e6733c55fce246f

Try grabbing the source code and compiling the library directly with the latest version. I will work on providing new compiled libs next week.