当我单击手机上的首选项标题时，应用程序崩溃

Question

I am working on simple settings activity. I am using preference-headers, PreferenceFragment, multiple preference-screen files and PreferenceActivity. I want it to look like and work like android system Settings. Everything works fine on tablet. Settings activity display two fragments, one with headers and one with preference-screen. When i open app on the phone, it displays just one fragment with headers, which is exactly what i want, but when i click on something, app crashes. I want to make it working exactly like android system settings, which means that when i click on something on phone, it replaces fragment with preference-screen. Thank you for your help.

Here is my code:

headers.xml

<preference-headers
    xmlns:android="http://schemas.android.com/apk/res/android">

    <header
        android:fragment="settingsApps.com.bendit.ILY.mysetts.PrefsF"
        android:title="@string/settings_update"
        android:summary="@string/settings_updateSummary" >
    </header>
    <header
        android:fragment="settingsApps.com.bendit.ILY.mysetts.PrefsF"
        android:title="@string/settings_display"
        android:summary="@string/settings_displaySummary">
    </header>
    <header
        android:fragment="settingsApps.com.bendit.ILY.mysetts.PrefsF"
        android:title="@string/settings_notify">
    </header>

</preference-headers>

PreferenceActivity(Prefs.java)

public class Prefs extends PreferenceActivity {
    public void onBuildHeaders(List<Header> target) {
        loadHeadersFromResource(R.xml.headers, target);
    }
}

PreferenceFragment(PrefsF.java)

public class PrefsF extends PreferenceFragment{
    @Override
    public void onCreate(Bundle savedInstanceState) {

        int preferenceFile_toLoad=-1;
        String settings = getArguments().getString("settings");
        if (Constants.SETTING_UPDATE.equals(settings)) {
            // Load the preferences from an XML resource
            preferenceFile_toLoad= R.xml.preference_update;
        }else if (Constants.SETTING_DISPLAY.equals(settings)) {
            // Load the preferences from an XML resource
            preferenceFile_toLoad=R.xml.preference_display;
        }else if (Constants.SETTING_NOTIFY.equals(settings)) {
            // Load the preferences from an XML resource
            preferenceFile_toLoad=R.xml.preference_notify;
        }

        addPreferencesFromResource(preferenceFile_toLoad);
    }
}

Answer 1

You get that error because your Preference Activity is wrong set for the preference headers type, the correct way for the Activity is this:

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

@Override
public void onBuildHeaders(List<Header> target) {
    loadHeadersFromResource(R.xml.preference_headers, target);
    setContentView(R.layout.preference);
}

@Override
protected boolean isValidFragment(String fragmentName) {
    return (Prefs1.class.getName().equals(fragmentName)
            || Prefs2.class.getName().equals(fragmentName)
            || Prefs3.class.getName().equals(fragmentName));
}

Here Prefs"number" is the headers of the preferences like your PrefsF.