我的Android应用程序中有一个SettingsActivity。最初没有Actionbar,所以我实现了这个:
settings_toolbar.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/toolbar"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?attr/actionBarSize"
app:navigationContentDescription="@string/abc_action_bar_up_description"
android:background="?attr/colorPrimary"
app:navigationIcon="?attr/homeAsUpIndicator"
app:title="@string/action_settings"
/>
SettingsActivity.java
public class SettingsActivity extends PreferenceActivity {
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
LinearLayout root = (LinearLayout)findViewById(android.R.id.list).getParent().getParent().getParent();
Toolbar bar = (Toolbar) LayoutInflater.from(this).inflate(R.layout.settings_toolbar, root, false);
root.addView(bar, 0); // insert at top
bar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
}
}
它很好但仅适用于第一个PreferenceScreen。如果我有一个嵌套的PreferenceScreen,那么就没有ActionBar。 我怎样才能实现这一点,在嵌套的PreferenceScreen上还有一个带后退按钮的ActionBar?
它应该与API15 +和AppCombat兼容
原帖:How to add Action Bar from support library into PreferenceActivity?
答案 0 :(得分:2)
我们可以使用简单的可点击首选项,而不是使用嵌套的PreferenceScreen,使其像“嵌套标题”一样工作;这将显示通常的ActionBar,因为它启动了PreferenceActivity实例,因此也将维护单窗格/双窗格导航样式。 这是一些简化的示例代码,其中包括ActionBar的后导航按钮设置:
<强> main_preferences.xml 强>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android"
android:orderingFromXml="true">
<Preference
android:key="a_preference" />
<!-- this is our "nested header", a simple Preference -->
<Preference
android:key="subscreen_preference" />
<Preference
android:key="another_ preference" />
</PreferenceSreen>
<强> subscreen_preference.xml 强>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android"
android:orderingFromXml="true">
<Preference
android:key="sub_preference" />
<!-- etc -->
</PreferenceSreen>
<强> MyPreferenceActivity.class 强>
public class MyPreferenceActivity extends AppCompatPreferenceActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//display back button. Fragments will handle its behavior (see below)
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
@Override
public void onBuildHeaders(List<Header> target) {
loadHeadersFromResource(R.xml.pref_headers, target);
}
@Override
protected boolean isValidFragment(String fragmentName) {
return MainPreferenceFragment.class.getName().equals(fragmentName) ||
SubscreenFragment.class.getName().equals(fragmentName);
}
public static class MainPreferenceFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
//let the fragment intercept the ActionBar buttons:
setHasOptionsMenu(true);
addPreferencesFromResource(R.xml.main_preferences);
findPreference("subscreen_preference").setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
@Override
public boolean onPreferenceClick(Preference preference) {
//we create a Header manually:
Header header = new Header();
//mandatory fragment name:
header.fragment = "com.foo.MyPreferenceActivity$SubscreenFragment";
//subscreen title to be shown in the ActionBar
header.titleRes = R.string.settings_fragment_title;
//this will do the trick, no further action required:
//we can ignore the second parameter
((MyPreferenceActivity)getActivity()).onHeaderClick(header, 0);
return true;
}
});
}
//this will make the ActionBar back navigation button
// behave like the system back button
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
if (!super.onOptionsItemSelected(item)) {
getActivity().onBackPressed();
}
return true;
}
return super.onOptionsItemSelected(item);
}
}
public static class SubscreenFragment extends PreferenceFragment {
//usual implementation
}
}
重要:如果你使用Proguard,请记得添加以下规则,否则isInvalidFragment()将返回false:
-keepnames class com.foo.MyPreferenceActivity$SubscreenFragment