我在Android TV的應用正與一個MainFragment
擴展BrowseFragment
,有時在BrowseFragment
爲mOnFocusSearchListener
定義的方法onFocusSearch(View focused, int direction)
崩潰:BrowseFragment中onFocusSearch上的NullPointerException?
private final BrowseFrameLayout.OnFocusSearchListener mOnFocusSearchListener =
new BrowseFrameLayout.OnFocusSearchListener() {
@Override
public View onFocusSearch(View focused, int direction) {
// if headers is running transition, focus stays
if (mCanShowHeaders && isInHeadersTransition()) {
return focused;
}
if (DEBUG) Log.v(TAG, "onFocusSearch focused " + focused + " + direction " + direction);
if (getTitleView() != null && focused != getTitleView() &&
direction == View.FOCUS_UP) {
return getTitleView();
}
if (getTitleView() != null && getTitleView().hasFocus() &&
direction == View.FOCUS_DOWN) {
return mCanShowHeaders && mShowingHeaders ?
mHeadersFragment.getVerticalGridView() :
mMainFragment.getView();
}
boolean isRtl = ViewCompat.getLayoutDirection(focused) == View.LAYOUT_DIRECTION_RTL;
int towardStart = isRtl ? View.FOCUS_RIGHT : View.FOCUS_LEFT;
int towardEnd = isRtl ? View.FOCUS_LEFT : View.FOCUS_RIGHT;
if (mCanShowHeaders && direction == towardStart) {
if (isVerticalScrolling() || mShowingHeaders) {
return focused;
}
return mHeadersFragment.getVerticalGridView();
} else if (direction == towardEnd) {
if (isVerticalScrolling()) {
return focused;
}
return mMainFragment.getView(); //*****CRASH******
} else {
return null;
}
}
};
注:這裏崩潰發生標有//*****CRASH******
線。 這次崩潰並不總是出現,但當它確實表示mMainFragment
是null
...
找不到問題。幫幫我!
更新leanback庫,會有幫助嗎?
不要把引用片段,嘗試從'FragmentManager'得到他們。 – Titus