问题
I am building an Android TV app with the following layout:
Both lists on the left and on the right are RecyclerViews with vertical LinearLayoutManagers, Header view is static. Navigation with D-PAD works fine within one list, but when switching from one list to another there are issues. Focus moves from, say list1's item 5 to list2' item 5. When list 2 is short has less than 5 items, it just loses focus.
I want the last focused item index saved and when the user navigates list1-list2-list1 the item with that index to gain focus again and also prevent the views from losing focus. Is there any good solution to this?
Required behaviour: user navigates to the top of the list and presses "UP" - focus stays where it was, nothing happens. user navigates to the bottom of the list and presses "DOWN" - focus stays where it was, nothing happens. user navigates from list1 to list2 - the item, that previously had focus in list2, gains focus or item0 gains focus if none was focused previously.
main layout:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ImageView
android:id="@+id/iv_background"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:focusable="false"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="27dp"
android:layout_marginLeft="48dp"
android:layout_marginRight="48dp"
android:layout_marginTop="27dp"
android:orientation="horizontal"
>
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2"
android:orientation="vertical"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:focusable="false"
android:orientation="horizontal"
>
<ImageView
android:id="@+id/iv_poster"
android:layout_width="@dimen/episodes_list_item_height"
android:layout_height="@dimen/episodes_list_image_width"
/>
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical"
>
<TextView
android:id="@+id/tv_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<TextView
android:id="@+id/tv_release_date"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
/>
<TextView
android:id="@+id/tv_rating"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:drawableLeft="@drawable/ic_star_white_24dp"
android:drawablePadding="@dimen/view_padding_small"
/>
</FrameLayout>
<TextView
android:id="@+id/tv_description"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
/>
</LinearLayout>
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/rv_seasons_list"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:focusable="false"
/>
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/rv_episodes_list"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="3"
android:focusable="false"
/>
</LinearLayout>
</FrameLayout>
item layout, used for both lists:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="@dimen/seasons_list_item_height"
android:orientation="horizontal"
android:focusable="true"
>
<TextView
android:id="@+id/tv_title"
android:layout_width="0dp"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:layout_weight="1"
/>
<TextView
android:id="@+id/tv_episodes_count"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:ems="10"
/>
</LinearLayout>
回答1:
Digging through Google's Leanback library sources answered my payers. If you face the same trouble, just wrap your RecyclerViews with this and don't forget to set
private boolean mPersistFocusVertical = false;
if you want the focus to be persisted when searching horizontally, like in my layout.
回答2:
Modify your main layout as below.
For directional navigation we can add properties like nextFocusDown, nextFocusLeft, nextFocusRight, nextFocusUp to focus relevant items as per our requirements.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ImageView
android:id="@+id/iv_background"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:focusable="false"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="27dp"
android:layout_marginLeft="48dp"
android:layout_marginRight="48dp"
android:layout_marginTop="27dp"
android:orientation="horizontal"
>
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="2"
android:orientation="vertical"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:focusable="false"
android:orientation="horizontal"
>
<ImageView
android:id="@+id/iv_poster"
android:layout_width="@dimen/episodes_list_item_height"
android:layout_height="@dimen/episodes_list_image_width"
/>
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical"
>
<TextView
android:id="@+id/tv_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<TextView
android:id="@+id/tv_release_date"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
/>
<TextView
android:id="@+id/tv_rating"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:drawableLeft="@drawable/ic_star_white_24dp"
android:drawablePadding="@dimen/view_padding_small"
/>
</FrameLayout>
<TextView
android:id="@+id/tv_description"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
/>
</LinearLayout>
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/rv_seasons_list"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:focusable="false"
android:nextFocusDown="@+id/rv_episodes_list"
/>
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/rv_episodes_list"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="3"
android:focusable="false"
android:nextFocusUp="@+id/rv_seasons_list"
/>
</LinearLayout>
Hope this will solve your problem !!
来源：https://stackoverflow.com/questions/35203829/android-tv-move-focus-between-recyclerviews