how to make checkbox stay checked when program closes?

Question

在我的程序中，我有大约20个复选框，但是当我选中它们并关闭程序然后再返回到复选框时，它们始终处于未选中状态，如何使该复选框保持选中状态。

Answer 1

In your onPause function, write the states to a file or to a SharedPreference. In your onResume, read that file/Preference in and set the checkboxes. You may want to look at PreferenceActivity to do this for you.

Answer 2

You can use SharedPreferences to do this.

So first, when your application goes to onPause , you'll want to store the state of each checkbox in SharedPreferences :

SharedPreferences prefs = this.getSharedPreferences("com.example.myapp", Context.MODE_PRIVATE);
prefs.putBoolean("checkbox1", checkbox1.isChecked()).commit();
// do this for all 20

Then you can check the checkboxes onResume and onCreate :

checkbox1.setChecked(prefs.getBoolean("checkbox1", false));

Answer 3

You should look into using Shared Preferences .

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);

Writing to Shared Preferences :

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putInt(getString(R.string.saved_high_score), newHighScore);
editor.commit();

Reading from Shared Preferences

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
int defaultValue = getResources().getInteger(R.string.saved_high_score_default);
long highScore = sharedPref.getInt(getString(R.string.saved_high_score), defaultValue);

Also here is a very simple tutorial on implementing them.

Requested Example Code :

Main Activity Class :

package com.zeus.example;

import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.widget.CheckBox;

public class MainActivity extends Activity {

CheckBox chkBox1, chkBox2;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    chkBox1 = (CheckBox) findViewById(R.id.checkBox1);
    chkBox2 = (CheckBox) findViewById(R.id.checkBox2);

    SharedPreferences getPrefs = 
            PreferenceManager.getDefaultSharedPreferences(getBaseContext());

    boolean value = getPrefs.getBoolean("checkbox_preference", true);
    chkBox1.setSelected(value); // Setting the value reflected from the preference
    chkBox2.setSelected(!value); // Setting the value opposite of the preference(Just an example)
}
}

Preference Activity Class :

package com.zeus.example;

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

public class Prefs extends PreferenceActivity{

    @SuppressWarnings("deprecation")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
       // TODO Auto-generated method stub
       super.onCreate(savedInstanceState);
       addPreferencesFromResource(R.xml.settings);
   }
}

Settings XML :

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
        xmlns:android="http://schemas.android.com/apk/res/android">
        <CheckBoxPreference
               android:key="checkbox_preference"
               android:defaultValue="false"
              android:title="CheckBox1"
        />
</PreferenceScreen>

Although this method is easy, it's deprecated and is recommended to use Preference Fragments instead

Answer 4

Use SharedPreferences . The simplest way to store small values forever.

Since you have multiple check boxes use SharedPreferences.Editor putStringSet (String key, Set<String> values)

You can use SimpleSharedPreferences in which putStringSet is backported to API-1.

Usage: No Edit, No Commit.

SimpleSharedPreferences mPreferences = new SimpleSharedPreferences(getApplicationContext()); //Init.

mPreferences.putStringSet("STRING_SET_KEY", mStringSet); //Single Line 

mPreferences.getStringSet("STRING_SET_KEY", null); // Get String set.

mPreferences.putBoolean("INTEGER_BOOL", true); //Just an example.

Note : I am the author of SimpleSharePreferences.