问题
I have created an app settings with Preferences. But I noticed, that there no toolbar in my PreferenceActivity. How I can add toolbar to my PreferenceActivity?
My code:
my pref_xml:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
<ListPreference
android:key="select_class"
android:title="@string/select_class"
android:defaultValue="0"
android:entries="@array/classy"
android:entryValues="@array/classy"
android:dialogTitle="@string/select_class" />
</PreferenceScreen>
my PrefActivity.java:
package ***.***.***;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
public class PrefActivity extends PreferenceActivity {
@Override
protected void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
getFragmentManager().beginTransaction().replace(android.R.id.content, new PrefFragment()).commit();
}
public static class PrefFragment extends PreferenceFragment
{
@Override
public void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.pref);
}
}
}
P.S Gautam, at your .java code there's an error in the line:
setSupportActionBar(toolbar); :
java.lang.RuntimeException: Unable to start activity ComponentInfo{xxx/xxx.PrefActivity}: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5349)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
Caused by: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead.
at android.support.v7.app.AppCompatDelegateImplV7.setSupportActionBar(AppCompatDelegateImplV7.java:198)
at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:130)
at com.smartfon_apps.timetable_sch32.PrefActivity.onCreate(PrefActivity.java:21)
at android.app.Activity.performCreate(Activity.java:6020)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2284)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5349)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
回答1:
Use an activity extending AppCompatActivity containing your toolbar referenced from layout file like below
public class UserSettingPreference extends AppCompatActivity {
Toolbar toolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.toolbar);
toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("Settings");
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onBackPressed();
}
});
getFragmentManager().beginTransaction().replace(R.id.fragment_container,
new UserPreferenceFragment()).commit();
}
}
Define your layout containing a toolbar and a framelayout to hold the fragment
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Toolbar
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#80000000"
android:minHeight="?android:attr/actionBarSize"
app:contentInsetEnd="0dp"
app:contentInsetLeft="0dp"
app:contentInsetRight="0dp"
app:contentInsetStart="0dp"/>
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</LinearLayout>
Then define your fragment extending preference fragment like below -
public class UserPreferenceFragment extends PreferenceFragment
To refer to your preference.xml override onCreate of fragment like below -
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.fragment_preference);
}
To refer particular elements inside your preference.xml use getPreferenceScreen method
switchPreference = (SwitchPreference) getPreferenceScreen().findPreference("floating_widget");
来源：https://stackoverflow.com/questions/39200846/how-to-add-toolbar-in-preferenceactivity