binding - MvvMCross bind command with parameter (in C# code)

Question

How can I bind a command to a button in code in MvvMCross (Xamarin.iOS) with specifying a command parameter?

// command definition
public MvxCommand SaveDealerDataCommand
{
    get { return new MvxCommand<bool>(DoSaveDealerDataAction); }
}

public void DoSaveDealerDataAction(bool show)
{
    //...
}

// binding
bindingset.Bind(saveButton).To(vm => vm.SaveDealerDataCommand); 

Where can I specify the parameter (true/false) that will be passed to the command?

Answer 1

Android and iOS buttons don't have CommandParameter properties in the same way that Windows ones do.

However, MvvmCross did recently introduce a way to introduce CommandParameter bindings via Value Converters - see http://slodge.blogspot.co.uk/2013/06/commandparameter-binding.html

This binding should work as:

 bindingset
    .Bind(saveButton)
    .To(vm => vm.SaveDealerDataCommand)
    .WithConversion("CommandParameter", true);     

or:

 bindingset
    .Bind(saveButton)
    .To(vm => vm.SaveDealerDataCommand)
    .WithConversion(new MvxCommandParameterValueConverter(), true);     

Note that this CommandParameter binding isn't completely in the 3.0.8.1 package which is the stable nuget release, so to make this work you may need to either:

1. Add this manual value converter registration in your Setup.cs

   protected override void FillValueConverters(IMvxValueConverterRegistry registry)
   {
       base.FillValueConverters(registry);
       registry.AddOrOverwrite(
           "CommandParameter", 
           new Cirrious.MvvmCross.Binding.MvxCommandParameterValueConverter()
       );
   }
   

2. Or use one of the beta nuget packages uploaded since 3.0.8.1 (set nuget to include prereleases to see these packages).

3. Or build the source yourself