如何在重新启动，按回并更改方向后保留android app imageButton的onClick状态

Question

I am making an app that control light bulb remotely. so i require that app saves automatically the previous state(variables, onlick button, etc) and resume it after i restart the app. For example if i pressed on bulb(in my code it changes picture on click) and picture changes so when i close app and reopen it, the image shown should be changed one.

Here's my code

package room.bt4u.com.roomcontrol;
import android.media.MediaPlayer;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageSwitcher;
public class MainActivity extends AppCompatActivity {
ImageButton ib;
MediaPlayer toggleSound;
ImageButton aButton,aButton2;

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    toggleSound=MediaPlayer.create(this, R.raw.z);
    aButton = (ImageButton) findViewById(R.id.imageButton);
    aButton2 = (ImageButton) findViewById(R.id.imageButton2);
    SharedPreferences sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
    Boolean c = sharedPreferences.getBoolean("clicked", false);
    Boolean d = sharedPreferences.getBoolean("clicked2",false);

    if(c) {
        aButton.setImageResource(R.drawable.on);
    }
    else {
        aButton.setImageResource(R.drawable.off);

    }
    if(d){

        aButton2.setImageResource(R.drawable.on);
    }
    else {

        aButton2.setImageResource(R.drawable.off);
    }
    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}


public void buttonClick(View v) {
    SharedPreferences sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
    Boolean c = sharedPreferences.getBoolean("clicked",false);
    if (!c) {
        aButton.setImageResource(R.drawable.on);
        toggleSound.start();
        sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putBoolean("clicked", true);
        editor.commit();
    }
    if(c){
        aButton.setImageResource(R.drawable.off);
        sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor = sharedPreferences.edit();
        editor.putBoolean("clicked", false);
        editor.commit();
        toggleSound.start();

    }
}
public void buttonClick2(View v) {
    SharedPreferences sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
    Boolean d = sharedPreferences.getBoolean("clicked",false);
    if (!d) {
        aButton2.setImageResource(R.drawable.on);
        toggleSound.start();
        sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putBoolean("clicked2", true);
        editor.commit();
    }
    if(d){
        aButton2.setImageResource(R.drawable.off);
        sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor = sharedPreferences.edit();
        editor.putBoolean("clicked2", false);
        editor.commit();
        toggleSound.start();

    }
}

And here's the XML FILE

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="room.bt4u.com.roomcontrol.MainActivity"
android:orientation="vertical">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="ROOM NO. 1046"
    android:textSize="45sp"
    android:textStyle="bold"
    android:layout_centerHorizontal="true"
    android:textColor="#0786e7"
    android:id="@+id/textView"
    android:includeFontPadding="false"
   android:gravity="center_horizontal"
    />


<ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/imageButton"
    android:layout_below="@+id/textView"
    android:src="@drawable/off"
    android:layout_marginTop="35dp"
    android:layout_alignParentLeft="true"
    android:background="#01FFFFFF"
    android:onClick="buttonClick"/>

<ImageButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/imageButton2"
    android:layout_alignTop="@+id/imageButton"
    android:layout_below="@+id/textView"
    android:src="@drawable/off"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:background="#01FFFFFF"
    android:onClick="buttonClick2"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="Swarnveer&apos;s"
    android:id="@+id/textView2"
    android:layout_below="@+id/imageButton"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginLeft="20dp"
    android:textStyle="bold"
    android:textColor="#f20606"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceMedium"
    android:text="Sajal&apos;s"
    android:id="@+id/textView3"

    android:layout_below="@+id/imageButton2"
    android:layout_alignRight="@+id/imageButton2"
    android:layout_alignEnd="@+id/imageButton2"
    android:layout_marginRight="35dp"
    android:layout_marginEnd="35dp"
    android:textStyle="bold"
    android:textColor="#f20606"/>

</RelativeLayout>

Answer 1

You can use SharedPreferences:

referring here for the infos: You can use SharedPreferences to save little setting datas on your phone.

In your onPause() , use the following code:

SharedPreferences prefs = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);
prefs.edit().putString("myKey", "myColorState").apply();

In this way the setting of "myColorState" is saved under the key "myKey".

In onResume() you can retrieve this value using

SharedPreferences prefs = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);
String myColor = prefs.getString("myKey", "defaultValue"); 

In this way you have your datas and you can use them in the activity

Answer 2

If you don't have bidirectional communication with the Bulb, saving the states to SharedPreferences seems like the best way to go.

You can retrieve the data from the SharedPreferences in your Activity or Fragment lifecycle Methods ( onConfigurationChanged() , onResume() , onStart() ).

Check out SharedPreferences here

Answer 3

您可以使用SharedPref通过更改屏幕方向或按Backpress上的任何键来保存数据，也可以使用此键再次获取该数据。

Answer 4

    Try this:


        @Override
        protected void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            toggleSound= MediaPlayer.create(this, R.raw.z);
            SharedPreferences sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
            Boolean c = sharedPreferences.getBoolean("clicked");
            if(c){
                aButton.setImageResource(R.drawable.on);
            }
            else {
                aButton.setImageResource(R.drawable.off);
            }        
        }


        public void buttonClick(View v) {
            switch (choose){
                case 1:ImageButton aButton = (ImageButton) v;
                    aButton.setImageResource(R.drawable.on);
                    toggleSound.start();
                    choose++;
                    SharedPreferences sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
                    SharedPreferences.Editor editor = sharedPreferences.edit();
                    editor.putBoolean("clicked", true);
                    editor.commit();
                    break;
                case 2:ImageButton bButton = (ImageButton) v;
                    bButton.setImageResource(R.drawable.off);
SharedPreferences sharedPreferences = getSharedPreferences("NAME", Context.MODE_PRIVATE);
                    SharedPreferences.Editor editor = sharedPreferences.edit();
                    editor.putBoolean("clicked", false);
                    editor.commit();
                    toggleSound.start();
                    choose--;
                    break;
            }