Wednesday, May 01, 2013

N=6 - Books over the network (N+1 days of MvvmCross)

Today we make another 4 platform example.

This time:
  • we include a very simple REST service - which sends GET requests to the Google Books search API
  • we include the JSON plugin to decode the requests
  • we try to use the Visual Designers to help produce nicer UIs

You'll quickly spot that I'm not very good with the designers - it's not them, it's me :)

Here's the video:

You'll see that I hit a couple of errors along the way:
  • I initially got my namespace wrong - sorry - just had to fix it during the demo!
  • A bug in  the JSON plugin NuGet package for MvvmCross - have already fixed in v3 (but not uploaded to yet)
  • A possible bug in Mono (MonoTouch?) with SSL - will report to Xamarin and see what they say

Completed code is on:

For more on the Google Books API try

For more on json to C# conversion, see

.... or try

Update: I then moved across to the Mac and did a prettier cell design - here it is:

Previously in N+1:


  1. I have this problem on last branch


    public string authorSummary
    get { return authors == null ? "-" : string.Join(", ", authors); }

    /Users/Downloads/NPlus1DaysOfMvvmCross-master/N-06-Books/Book.Core/Services/VolumeInfo.cs(57,57): Error CS1502: The best overloaded method match for `string.Join(string, string[])' has some invalid arguments (CS1502) (Books.Core)

    /Users/Downloads/NPlus1DaysOfMvvmCross-master/N-06-Books/Book.Core/Services/VolumeInfo.cs(68,68): Error CS1503: Argument `#2' cannot convert `System.Collections.Generic.List' expression to type `string[]' (CS1503) (Books.Core)

    /Users/Downloads/NPlus1DaysOfMvvmCross-master/N-06-Books/Book.Core/ViewModels/FirstViewModel.cs(40,40): Error CS1684: Reference to type `System.Func`1' claims it is defined assembly `mscorlib, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089', but it could not be found (CS1684) (Books.Core)

  2. What are you compiling on? Sounds like the same error as the unity guys saw - but they were using an old .net version - see

  3. I had configured Xamarin Studio in beta. I did a rollback in stable and now works correctly!

    Thanks for support!

  4. Hi, I have problem about displaying images on my android project. Title and author have no problem but I can't display images with this layout;

    I checked the json document on link and follow path where the smallThumbnail is located. Do you have any suggestion.
    Thank you..