MvxBind没有按下按钮

Question

我关注this tutorial以及他们使用mvxbind将他们的Home，Info和第三个片段用于他们各自的视图模型的方式。我尝试对我的其他片段做同样的事情，但我不知道我做错了什么，但是MvxBind没有用。这是我的viewmodel和layout的代码。

SomeViewModel.cs

public class SomeViewModel : BaseViewModel
{
    public SomeViewModel()
    {

    }

    private MvxCommand someViewModelCommand;

    public MvxCommand SomeViewModelCommand
    {
        get
        {
            someViewModelCommand = someViewModelCommand ?? new MvxCommand(DoSomeViewModel);
            return someViewModelCommand;
        }
    }

    private void DosomeViewModel()
    {
        ShowViewModel<FirstViewModel>();
    }

}

FirstViewModel.cs

public class FirstViewModel : BaseViewModel
{
    public FirstViewModel()
    {
        First = "Some Info for you...";
    }

    public string First
    {
        get;
        private set;
    }
}

现在我有这样的布局： SomeLayout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:local="http://schemas.android.com/apk/res-auto"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        local:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
</android.support.design.widget.AppBarLayout>
<Button
    android:id="@+id/someButton"
    android:text="Do Something"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    local:MvxBind="Click SomeViewModelCommand" />
</LinearLayout>

更新

SomeFragment.cs

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        // Use this to return your custom view for this Fragment
        // return inflater.Inflate(Resource.Layout.YourFragment, container, false);
        ShowHamburgerMenu = true;
        oldTitle = ((MainActivity)Activity).Title;
        ((MainActivity)Activity).Title = "Track Packages";
        //var view = base.OnCreateView(inflater, container, savedInstanceState);

        var ignored = base.OnCreateView(inflater, container, savedInstanceState);

        var view = this.BindingInflate(Resource.Layout.fragment_trackpackage, container, false);
        return view;
    }