BottomSheetDialogFragment + ViewPager+Fragment+RecyclerView這種樣式出現的不多,所以前一陣做這類需求的時候遇到種種問題。
主要的原因就是因爲BottomSheetBehavior的findScrollingChild方法並沒有有關ViewPager 更新查找子元素view的東西,所以它只能拿到一個頁面去滑動,那麼就需要對BottomSheetBehavior進行修改,這樣的話就需要自己定義BottomSheetDialog。
private View findScrollingChild(View view) {
if (view instanceof NestedScrollingChild) {
return view;
}
if (view instanceof ViewGroup) {
ViewGroup group = (ViewGroup) view;
for (int i = 0, count = group.getChildCount(); i < count; i++) {
View scrollingChild = findScrollingChild(group.getChildAt(i));
if (scrollingChild != null) {
return scrollingChild;
}
}
}
return null;
}
修改後的結果:
@VisibleForTesting
View findScrollingChild(View view) {
if (ViewCompat.isNestedScrollingEnabled(view)) {
return view;
}
if (view instanceof ViewPager) {
ViewPager viewPager = (ViewPager) view;
View currentViewPagerChild = viewPager.getChildAt(viewPager.getCurrentItem());
// View currentViewPagerChild = ViewPagerUtils.getCurrentView(viewPager);
if (currentViewPagerChild == null) {
return null;
}
View scrollingChild = findScrollingChild(currentViewPagerChild);
if (scrollingChild != null) {
return scrollingChild;
}
} else if (view instanceof ViewGroup) {
ViewGroup group = (ViewGroup) view;
for (int i = 0, count = group.getChildCount(); i < count; i++) {
View scrollingChild = findScrollingChild(group.getChildAt(i));
if (scrollingChild != null) {
return scrollingChild;
}
}
}
return null;
}
還有注意的一點是這種結合 RecyclerView不要在其外層加那種帶手勢一些事件攔截的ViewGroup,這樣會有一些衝突。比如刷新組件SwipeRefreshLayout 和一些上拉加載的組件。如果想要實現上拉加載那就在RecyclerView本身上實現。
具體demo請看我github:https://github.com/JiangAndroidwork/BottomSheetViewPager