尽管添加了PreferenceFragment，但PreferenceActivity为空 [英] Empty PreferenceActivity though a PreferenceFragment was added

问题描述

我遇到了一个非常简单的问题:我正在尝试在应用中构建首选项"屏幕，并且希望使用新的，现在已经成为标准的PreferenceFragment方法.

I'm stuck with a pretty simple issue: I'm trying to build a Preference screen in my app and I'd like to do it with the new, now-standard PreferenceFragment method.

这是我的首选项xml:

This is my prefs xml:

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

    <PreferenceCategory android:title="@string/prefs_interface_settings">

    <SwitchPreference
        android:key="show_average"
        android:title="Show average length of work day"
        android:defaultValue="false"
        android:summary="Display the calculated average in the app title" />

    <EditTextPreference
        android:key="edittext_preference"
        android:title="@string/workday_duration_prefs_title"
        android:summary="summary_edittext_preference"
        android:defaultValue="8"
        android:dialogTitle="dialog_title_edittext_preference" />

    </PreferenceCategory>
</PreferenceScreen>

这是我的SettingsActivity

This is my SettingsActivity

import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.widget.Toast;


public class SettingsActivity extends PreferenceActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getFragmentManager().beginTransaction().replace(android.R.id.content, new SettingsFragment()).commit();
    }
}

最后-这是我的SettingsFragment:

and - finally - this is my SettingsFragment:

import android.os.Bundle;
import android.preference.PreferenceFragment;


public class SettingsFragment extends PreferenceFragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            addPreferencesFromResource(R.xml.app_preferences); //Gets settings from XML
        }
    }

}

当我运行该应用程序时，如果我确实打开了上述活动，则会得到一个空的活动，就像由于某种原因该片段未初始化(或未显示)一样.但是代码是如此简单……我做错了！

When I run the application, if I do open said activity I get an empty one, just like the fragment was not initialized - or not shown - for some reason. But the code is so simple... I just can't get what I do wrong!

谢谢大家的帮助

推荐答案

<preference-headers/>时使用.在首选项XML文件的<extra/>元素中声明的参数.声明后，将在PreferenceFragment:

getArguments() used only when you create <preference-headers/>. The arguments declared in <extra/> element of the preference-header XML file. Once you declared it, you will call this code within PreferenceFragment:

String settings = getArguments().getString("settings");
if (settings.equals("myArgument")) {
    addPreferencesFromResource(R.xml.settings_wifi);
}

但是，由于您不使用<preference-headers/>，因此只需要在PreferenceFragment中调用此代码:

But, as you do not use <preference-headers/>, so you only need to call this code in the PreferenceFragment:

addPreferencesFromResource(R.xml.app_preferences);

这篇关于尽管添加了PreferenceFragment，但PreferenceActivity为空的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！