使用onResume / onStop作为首选项（设置）

Question

started a few days ago with Android, i'm kinda noob. I got a MainActivity with Weight, Width values. These values, can be whether Inches-Pounds or Cm-Kilograms.

How do i change these values? from Settings, i've created a simple Menu with a ListPreference. When selecting one of those two measures, i need to update my MainActivity with the new values. Why's that? I got the following

TextView : TextEdit

Weight ( Kilograms )

[ _ __ _ __ _ ___ ]

Width ( Cm )

[ _ __ _ __ _ ___ ]

Those texts between parentheses i want them to be dinamically changed after selecting in the settings menu.

This is the part of my code:

MainActivity getting the Preferences from prefs.xml

 @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        initializeAttributes();

        SharedPreferences getPrefs = PreferenceManager.getDefaultSharedPreferences(this);
        String measures = getPrefs.getString("MEASURE_KEY", "Inches-Pounds");


        String[] splitMeasure = measures.split("\\-");
        measureWeight.setText(measureWeight.getText() + " ( " + splitMeasure[1] + " )");
        measureHeight.setText(measureHeight.getText() + " ( " + splitMeasure[0] + " )");

This is the prefs.xml with the menu

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <PreferenceCategory                 
        android:title="@string/cat_language">   
        <ListPreference                    
            android:title="@string/title_language"            
            android:summary="@string/sum_language"    
            android:key="LANGUAGE_KEY"                         
            android:entries="@array/languages"            
            android:entryValues="@array/languages" 
            android:defaultValue="English"/>   
    </PreferenceCategory>      

    <PreferenceCategory             
        android:title="@string/cat_usage">   
        <ListPreference                    
            android:title="@string/title_measure"            
            android:summary="@string/sum_measure"    
            android:key="MEASURE_KEY"                    
            android:entries="@array/measures"            
            android:entryValues="@array/measures" 
            android:defaultValue="Inches-Pounds"/>  
    </PreferenceCategory>     

    <PreferenceCategory             
            android:title="@string/cat_help">   
        <Preference               
            android:title="@string/title_howto"  
            android:summary="@string/sum_howto"   
            android:key="HOWTO_KEY" />
        <Preference               
            android:title="@string/title_about"  
            android:summary="@string/sum_about"   
            android:key="ABOUT_KEY" />
    </PreferenceCategory>
</PreferenceScreen>

I even tried using the commit() but couldn't make it work either.

After trying using the onResume() what i got as a result was "fine" except for the fact it was adding me a ( measure ) everytime i change it from the settings, eg:

Weight ( Kilograms ) ( Pounds ) ( Kilograms ) ( Pounds ) and so on.

Can anyone help me on how to use the onResume method in this case?

Thanks in advance.

Answer 1

In the ListPreference change android:entryValues to android:entryValues="@array/measuresValues"

Your entries arrays should look something like this

<string-array name="measures">
    <item>Inches-Pounds</item>
    <item>Cm-Kilograms</item>
</string-array>   

and your entryValues array

<string-array name="measuresValues">
    <item>"Inches-Pounds"</item>
    <item>"Cm-Kilograms"</item>
</string-array>  

Then put this in the activity onResume()

SharedPreferences mysettings = PreferenceManager.getDefaultSharedPreferences(this);
String st1 = mysettings.getString("MEASURE_KEY", "default Value here");

if(st1.equals("Inches-Pounds")){ 
    //do some stuff here
    //like textview.setText.....
}
if(st1.equals("Cm-Kilograms")){ 
    //do some stuff here
}