Question

我正在使用最新Android的导航抽屉。

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:local="http://schemas.android.com/apk/res-auto"
    android:id="@+id/Home_HomeView_DrawerLayout" >
<!-- The main content view -->
    <FrameLayout
        android:id="@+id/Home_HomeView_ContentFrame" />
<!-- The navigation drawer -->

    <!-- ... -->

</android.support.v4.widget.DrawerLayout>

在我的HomeView中，我根据所选项目设置了Home_HomeView_ContentFrame片段

private void SelectItem(int position)
{
    var fragment = new HomeFragment(ViewModel);
    var arguments = new Bundle();
    fragment.Arguments = arguments;
    _actionBarTitle = ((HomeViewModel)ViewModel).NavigationItems[position].Text;

    SupportFragmentManager.BeginTransaction()
                          .Replace(Resource.Id.Home_HomeView_ContentFrame, fragment)
                          .Commit();

    _topDrawerList.SetItemChecked(position, true);
    ActionBar.Title = _actionBarTitle;


    _navigationDrawer.CloseDrawer(_drawerInnerLayout);
}

HomeFragment是为MvvmCross设置BindingContext

public sealed class HomeFragment : MvxFragment
{

    public HomeFragment(IMvxViewModel viewModel)
    {
        ViewModel = viewModel;
    }

    public override View OnCreateView(LayoutInflater layoutInflater, ViewGroup viewGroup, Bundle bundle)
    {
        // A breakpoint below shows that the ViewModel does in fact contain the IPlayCommand as expected.
        BindingContext = new MvxAndroidBindingContext(Activity, new MvxSimpleLayoutInflater(layoutInflater), ViewModel);
        var rootView = layoutInflater.Inflate(Resource.Layout.Home_HomeFragment, viewGroup, false);

        Activity.Title = Resources.GetString(Resource.String.ApplicationName);
        return rootView;
    }
}

在Home_HomeFragment布局中，我有一个绑定到IMvxCommand的按钮。请注意，此按钮基于@Stuart's example.

    <FutureState.AudioBook.Droid.Ui.Controls.FsmButton
        android:id="@+id/Home_HomeFragment_PlayPauseIcon"
        android:clickable="true"
        android:adjustViewBounds="true"
        local:MvxBind="Command PlayCommand; CommandParameter ." />

它绑定的ViewModel目前非常简单。

public class HomeViewModel : ViewModelBase
{
    public IList<NavigationItem> NavigationItems;

    public HomeViewModel(IPlayCommand playCommand)
    {
        // playCommand is being resolved by the IoC
        _playCommand = playCommand;
    }

    private IPlayCommand _playCommand;
    public IPlayCommand PlayCommand
    {
        get { return _playCommand; }
        set
        {
            _playCommand = value;
            RaisePropertyChanged(() => PlayCommand);
        }
    }
}

当我在BindingContext的{{1}}行放置BreakPoint时，我绝对可以看到使用PlayCommand填充的ViewModel。

我遇到的问题是触摸按钮的动作不会触发HomeFragment。我哪里错了？

Answer 1

Android inflate不了解mvvmcross绑定。

要使用基于XML的绑定，您必须使用BindingInflate - 请参阅http://mvvmcross.blogspot.com中包含https://github.com/MvvmCross/NPlus1DaysOfMvvmCross中代码的示例 - 包括n = 26中的片段 - https://github.com/MvvmCross/NPlus1DaysOfMvvmCross/blob/master/N-26-Fraggle/Rock.Droid/Views/SubFrag.cs

http://motzcod.es/post/60427389481/effective-navigation-in-xamarin-android-part-1

中还有导航抽屉样本

当按钮位于片段中时，将Button绑定到ViewModel命令

1 个答案: