Android 如何在更通用的PreferenceFragment中侦听首选项更改?
我使用PreferenceFragment和OnChangeListener实现了一个首选项屏幕,以显示当前值作为摘要。下面的代码工作得很好,但通过这种方式,我需要为每个首选项提供一个OnChangeListener 设置活动.javaAndroid 如何在更通用的PreferenceFragment中侦听首选项更改?,android,onchange,android-preferences,Android,Onchange,Android Preferences,我使用PreferenceFragment和OnChangeListener实现了一个首选项屏幕,以显示当前值作为摘要。下面的代码工作得很好,但通过这种方式,我需要为每个首选项提供一个OnChangeListener 设置活动.java import android.content.SharedPreferences; import android.content.SharedPreferences.OnSharedPreferenceChangeListener; import android
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
public class UserSettingActivity extends PreferenceActivity {
public static final String PREF_EXCERCISES = "pref_number_of_exercises";
public static final String PREF_TASKS = "pref_number_of_tasks";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Display the fragment as the main content.
getFragmentManager().beginTransaction().replace(android.R.id.content, new MyPreferenceFragment()).commit();
}
public static class MyPreferenceFragment extends PreferenceFragment {
@Override
public void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//add the settings.xml layout
addPreferencesFromResource(R.xml.settings);
// update the preferences if they change
setUpdatePreferences();
}
private void setUpdatePreferences() {
//get the specified preferences using the key declared in preferences.xml
ListPreference dataPrefConType = (ListPreference) findPreference(PREF_EXCERCISES);
//get the description from the selected item
dataPrefConType.setSummary( dataPrefConType.getEntry() );
//when the user choose other item the description changes too with the selected item
dataPrefConType.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
@Override
public boolean onPreferenceChange(Preference preference, Object o) {
preference.setSummary(o.toString());
return true;
}
});
}
}
}
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.util.Log;
public class UserSettingActivity extends PreferenceActivity {
public static final String PREF_EXCERCISES = "pref_number_of_exercises";
public static final String PREF_TASKS = "pref_number_of_tasks";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Display the fragment as the main content.
getFragmentManager().beginTransaction().replace(android.R.id.content, new MyPreferenceFragment()).commit();
}
public static class MyPreferenceFragment extends PreferenceFragment
implements OnSharedPreferenceChangeListener {
@Override
public void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//add the settings.xml layout
addPreferencesFromResource(R.xml.settings);
// update the preferences if they change
//setUpdatePreferences();
}
@Override
public void onResume() {
super.onResume();
getPreferenceManager().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
}
@Override
public void onPause() {
getPreferenceManager().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
super.onPause();
}
@Override
public void onSharedPreferenceChanged(
SharedPreferences sharedPreferences, String key) {
Log.i("settings", "preference changed: " + key);
}
}
}
preferences.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<EditTextPreference
android:defaultValue="15"
android:enabled="true"
android:key="pref_number_of_exercises"
android:numeric="integer"
android:title="Number of exercises" />
<EditTextPreference
android:defaultValue="15"
android:enabled="true"
android:key="pref_number_of_tasks"
android:numeric="integer"
android:title="Number of tasks" />
</PreferenceScreen>
它在哪里坠毁?这是什么样的碰撞?你能检查一下Logcat并提供更多的信息吗?我从头开始实现了这个东西,现在它可以工作了。看来我在什么地方做错了。无论如何谢谢你!