我想在我的 ActionBar 中显示一个微调器,使用ActionBar.NAVIGATION_MODE_LIST
,但我希望它根据某些应用程序上下文隐藏/显示。我发现我可以使用 将它从 ActionBar 中删除getActionBar().setNavigationMode(-1)
,但是我不知道这是否是个好主意。
关于这是否安全或是否有更安全的替代方案的任何反馈?
我想在我的 ActionBar 中显示一个微调器,使用ActionBar.NAVIGATION_MODE_LIST
,但我希望它根据某些应用程序上下文隐藏/显示。我发现我可以使用 将它从 ActionBar 中删除getActionBar().setNavigationMode(-1)
,但是我不知道这是否是个好主意。
关于这是否安全或是否有更安全的替代方案的任何反馈?
也许这更被接受:
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setDisplayShowTitleEnabled(false);
如果您坚持使用ActionBar.NAVIGATION_MODE_LIST
,则每次要显示微调器时都必须设置导航侦听器。这显然不是最好的解决方案。
相反,您可能希望使用ActionBar.setCustomView()
设置微调器导航(参考)。
这是一些设置微调器的示例代码:
Spinner navigationSpinner = new Spinner(this);
navigationSpinner.setAdapter(yourSpinnerAdapter);
// Here you set navigation listener
navigationSpinner.setOnItemSelectedListener(yourSpinnerNavigationListener);
getActionBar().setCustomView(navigationSpinner);
getActionBar().setDisplayShowCustomEnabled(true);
然后,当您想要显示/隐藏它时,您只需更改它的可见性:
getActionBar().getCustomView().setVisibility(View.INVISIBLE);
只需像这样修改您的实现ActionBarDrawerToggle
:
public void onDrawerSlide(View drawerView, float slideOffset) {
super.onDrawerSlide(drawerView, slideOffset);
if (slideOffset == 0) { // 0 = drawer is closed
setActionBarNavigationVisibility(activity, true); //show Tabs when Drawer is closed
}
}
public void onDrawerStateChanged(int newState) {
super.onDrawerStateChanged(newState);
//hides Tabs right after Drawer starts opening
if (DrawerLayout.STATE_DRAGGING == newState || DrawerLayout.STATE_SETTLING == newState) {
setActionBarNavigationVisibility(activity, false);
}
}
where 方法setActionBarNavigationVisibility
正在考虑所有导航模式(您可以删除不必要的导航模式的代码):
public static void setActionBarNavigationVisibility(Activity activity, boolean visible) {
try {
/* 1. --- If the navigation items are showing in ActionBar directly. We have 3 options Spinner, Tabs, and CustomNav ---
(When Tabs are showing BELOW ActionBar, is handled at the end) */
int actionViewResId = Resources.getSystem().getIdentifier("action_bar", "id", "android"); // @see http://stackoverflow.com/questions/20023483/how-to-get-actionbar-view
View actionBarView = activity.findViewById(actionViewResId); // returns instance of com.android.internal.widget.ActionBarView (inaccessible)
if (actionBarView != null) {
int visibility = visible ? View.VISIBLE : View.INVISIBLE; // not GONE, so it still takes space in ActionBar layout
// handle tabs navigation
Field mTabScrollViewField = actionBarView.getClass().getDeclaredField("mTabScrollView");
if (mTabScrollViewField != null) {
mTabScrollViewField.setAccessible(true);
View mTabScrollView = (View) mTabScrollViewField.get(actionBarView); // instance of com.android.internal.widget.ScrollingTabContainerView (inaccessible)
if (mTabScrollView != null)
mTabScrollView.setVisibility(visibility);
}
// handle Spinner navigation
Field mSpinnerField = actionBarView.getClass().getDeclaredField("mSpinner"); // resp. mListNavLayout
if (mSpinnerField != null) {
mSpinnerField.setAccessible(true);
View mSpinner = (View) mSpinnerField.get(actionBarView); // instance of android.widget.Spinner
if (mSpinner != null)
mSpinner.setVisibility(visibility);
}
// handle Custom navigation
Field mCustomNavViewField = actionBarView.getClass().getDeclaredField("mCustomNavView"); // resp. mListNavLayout
if (mCustomNavViewField != null) {
mCustomNavViewField.setAccessible(true);
View mCustomNavView = (View) mCustomNavViewField.get(actionBarView);
if (mCustomNavView != null)
mCustomNavView.setVisibility(visibility);
}
}
// 2. --- If the Tabs are BELOW ActionBar (narrow screens) ---
ViewParent actionBarContainer = actionBarView.getParent(); // parent of ActionBarView is com.android.internal.widget.ActionBarContainer (inaccessible)
Field mTabContainerField = actionBarContainer.getClass().getDeclaredField("mTabContainer");
if (mTabContainerField != null) {
mTabContainerField.setAccessible(true);
View mmTabContainer = (View) mTabContainerField.get(actionBarContainer);
if (mmTabContainer != null)
mmTabContainer.setVisibility(visible ? View.VISIBLE : View.GONE); // now use GONE, so the mTabContainer below Actionbar does not take space in layout
}
} catch (Exception ex) {
// TODO Handle exception...
}
}