焦点

1.确定当前焦点位置

ViewTreeObserver viewTreeObserver = getWindow().getDecorView().getViewTreeObserver();
        viewTreeObserver.addOnGlobalFocusChangeListener(new ViewTreeObserver.OnGlobalFocusChangeListener() {
            @Override
            public void onGlobalFocusChanged(View oldFocus, View newFocus) {
                Log.d(TAG, "oldFocus========" + oldFocus  + "newFocus============" + newFocus);
            }
        });

2.子view焦点跟随父View变化

android:duplicateParentState="true"

3.设置下一个获取焦点的View

android:nextFocusDown="@id/view1"
android:nextFocusUp="@id/view2"
android:nextFocusLeft="@id/view3"
android:nextFocusRight="@id/view4"

4.设置父View和子View哪个获取焦点

beforeDescendants ：viewGroup会优先其子类控件而获取到焦点
afterDescendants ：viewGroup只有当其子类控件不需要获取焦点时才获取焦点
blocksDescendants ：viewGroup会覆盖子类控件而直接获得焦点

5.常用的按键值

KEYCODE_BACK 4返回

KEYCODE_DPAD_DOWN 20

KEYCODE_DPAD_UP  19

KEYCODE_DPAD_LEFT 21

KEYCODE_DPAD_RIGHT 22

KEYCODE_ENTER = 66;

KEYCODE_MEDIA_REWIND　　快退

KEYCODE_MEDIA_FAST_FORWARD　快进

KEYCODE_VOLUME_DOWN = 25;

KEYCODE_VOLUME_MUTE = 164;

KEYCODE_VOLUME_UP = 24;

7.控制RecycleView焦点跳转逻辑

参考文章跳转逻辑逻辑修改

8.其他View焦点跳转到RecyclerView

Android系统的焦点跳转规则是就近跳转,以上两点可能无法满足。使用HorizontalGridView或者VerticalGridView则可以解决以上两点问题。

9.ViewGroup的某个子View获取焦点

handler.postDelayed(() -> {
            View child = videoPlayerHolder.ctrlInfoList.getChildAt(0);
            View list = child == null ? null : ((LinearLayout) child).getChildAt(1);
            View item = list == null ? null : ((HorizontalGridView) list).getChildAt(currentIndex);
            if (child == null || list == null) {
                videoPlayerHolder.ctrlInfoList.requestFocus();
            } else {
                if (item == null) {
                    list.requestFocus();
                } else {
                    item.requestFocus();
                }
            }
        }, 50);

0 条评论