如何将视图模型绑定到底部表

How to bind a viewmodel to a bottomsheet

我想弄清楚如何将视图模型绑定到底部表,这样我就可以使用视图模型上的可观察字段使底部表展开、折叠和隐藏。

谢谢!

您应该使用自定义 BindingAdapter

@BindingAdapter("bottomSheetBehaviorState")
public static void setState(View v, int bottomSheetBehaviorState) {
    BottomSheetBehavior<View> viewBottomSheetBehavior = BottomSheetBehavior.from(v);
    viewBottomSheetBehavior.setState(bottomSheetBehaviorState);
}

在 xml 中将其绑定到您的视图:

<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">  
(...)
        <android.support.v4.widget.NestedScrollView
            android:id="@+id/group_bottom_sheet"
            bottomSheetBehaviorState="@{viewModel.bottomSheetBehaviorState}"
            android:layout_width="match_parent"
            android:layout_height="250dp"
            android:background="@android:color/holo_blue_bright"
            app:behavior_hideable="true"
            app:behavior_peekHeight="50dp"
            app:layout_behavior="android.support.design.widget.BottomSheetBehavior"/>


(...)
</layout>

并更改 ViewModel 中的状态。我的 ViewModel 中的相关代码:

public final ObservableInt bottomSheetBehaviorState = new ObservableInt(BottomSheetBehavior.STATE_HIDDEN);


@Override
public void onAction(boolean show){
    bottomSheetBehaviorState.set(show? BottomSheetBehavior.STATE_COLLAPSED : BottomSheetBehavior.STATE_HIDDEN);
}