无法使用PreferenceActivity中的EditTextPreference更新值（非活动InputConnection）

Question

使用PreferenceActivity类，我想用EditTextPreference（EditTextPreference with android：key =“interval”）更新值，但输入的值没有考虑在内，输入值时出现此错误：

05-20 15:01:54.035 32516-32516/fr.lenours.sensortracker W/IInputConnectionWrapper: beginBatchEdit on inactive InputConnection
05-20 15:01:54.036 32516-32516/fr.lenours.sensortracker W/IInputConnectionWrapper: getSelectedText on inactive InputConnection
05-20 15:01:54.040 32516-32516/fr.lenours.sensortracker W/IInputConnectionWrapper: endBatchEdit on inactive InputConnection
05-20 15:01:54.040 32516-32516/fr.lenours.sensortracker W/IInputConnectionWrapper: getTextBeforeCursor on inactive InputConnection
05-20 15:01:54.042 32516-32516/fr.lenours.sensortracker W/IInputConnectionWrapper: getTextAfterCursor on inactive InputConnection

这是PreferenceActivity类和他的.xml：

Settings.class：

public class Settings extends PreferenceActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    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);
        addPreferencesFromResource(R.xml.preferences);
    }
}

}

preferences.xml：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <PreferenceCategory android:title="Graph">
        <EditTextPreference 
            android:defaultValue="30000"
            android:key="interval"
            android:title="Interval (Seconds)" />
        <fr.lenours.sensortracker.ConfirmationDialog
            android:key="removeSteps"
            android:summary="this action will remove the record"
            android:title="delete all step recording" />
    </PreferenceCategory>
    <PreferenceCategory android:title="Map">
        <fr.lenours.sensortracker.ConfirmationDialog
            android:key="removeRoute"
            android:summary="This action will delete map route"
            android:title="Delete route" />
        <fr.lenours.sensortracker.ConfirmationDialog
            android:key="removeMarkers"
            android:summary="this action will delete all markers on the map"
            android:title="Delete markers" />
    </PreferenceCategory>
    <PreferenceCategory android:title="Tracker">
        <EditTextPreference
            android:key="stepObjective"
            android:summary="Change your daily step objective"
            android:title="Step daily objective" />
    </PreferenceCategory>
</PreferenceScreen>

和 onSharedPreferenceChanged 方法：

@Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
    switch (key) {
        case "interval":
            int interval = Integer.parseInt(sharedPreferences.getString("interval", "30000"));
            stepGraphFrag.setInterval(interval * 1000); //second to microsecond
            Log.d("main","Interval Changed ! Interval = " + interval);
            stepGraphFrag.getHandler().removeCallbacks(stepGraphFrag.getUpdater());
            stepGraphFrag.getHandler().postDelayed(stepGraphFrag.getUpdater(), 0);
            break;
        case "removeSteps":
            if (sharedPreferences.getBoolean("removeSteps", true)) {
                stepGraphFrag.resetGraph();

            }
            Log.d("main","Remove steps ! bool = " + sharedPreferences.getBoolean("removeSteps", true));
            break;
        case "removeRoute":
            if (sharedPreferences.getBoolean("removeRoute", true)) {
                osmFrag.resetRoute();
            }
            break;
    }
}

如果你知道为什么我会收到这些警告，请提前感谢！