Bdtjtk

app
app

Hi, thanks in advance to those who guide me.

I have a problem with the Set Wallpaper, that when I clicked on the button, I get the following error:

2018-12-28 22: 36: 02.801 13030-13030 /? E / AndroidRuntime: FATAL EXCEPTION: main
     java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress (android.graphics.Bitmap $ CompressFormat, int, java.io.OutputStream)' on a null object reference

I leave the files used.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"



    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:layout_gravity="center"

    android:orientation="vertical"

    android:id="@+id/thumbnail2"

    android:padding="5dp">



    <TextView

        android:id="@+id/txtclose"

        android:layout_width="30dp"

        android:layout_height="30dp"

        android:layout_gravity="end"

        android:layout_marginTop="5dp"

        android:layout_marginEnd="5dp"

        android:layout_marginRight="5dp"

        android:layout_marginBottom="5dp"

        android:background="@drawable/circulo"

        android:gravity="center"

        android:text="@string/equis"

        android:textColor="@android:color/background_light"

        android:textStyle="bold" />



    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_gravity="center"

        android:orientation="vertical">

<FrameLayout

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:layout_gravity="end">



        <Button

                android:id="@+id/btn"

                android:layout_width="159dp"

                android:layout_height="wrap_content"

                android:layout_gravity="bottom|center"

                android:layout_marginBottom="25dp"

                android:background="@drawable/borde_redondo"

                android:text="Establecer como Fondo de Pantalla"

                android:textColor="#ffffff" />



</FrameLayout>

    </LinearLayout>

</LinearLayout>

public class infoanimales extends AppCompatActivity {

        private RequestOptions options;

        TextView txtclose;

        LinearLayout img;



        @Override

        protected void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_infoanimales);



            Button button = findViewById(R.id.btn);



            button.setOnClickListener(new View.OnClickListener() {

                @Override

                public void onClick(View v) {

                    setWallpaper();

                }

            });



            if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {

                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

            }



            this.options = new RequestOptions()

                    .diskCacheStrategy(DiskCacheStrategy.AUTOMATIC);



            String image_url = getIntent().getExtras().getString("img2");



            img = findViewById(R.id.thumbnail2);

            Glide.with(this).load(image_url).into(new SimpleTarget<Drawable>() {

                @Override

                public void onResourceReady(@NonNull Drawable fondoreceta, Transition<? super Drawable> transition) {

                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {

                        img.setBackground(fondoreceta);

                    }

                }

            });



            TextView txtclose = findViewById(R.id.txtclose);

            txtclose.setOnClickListener(new View.OnClickListener() {



                @Override

                public void onClick(View v) {



                    finish();

                }

            });

        }



        private void setWallpaper() {

            Bitmap bitmap = BitmapFactory.decodeFile("img2");

            WallpaperManager manager = WallpaperManager.getInstance(getApplicationContext());



            try {

                manager.setBitmap(bitmap);

                Toast.makeText(this, "Listo", Toast.LENGTH_SHORT).show();



            } catch (IOException e) {

                Toast.makeText(this, "error", Toast.LENGTH_SHORT).show();

            }

        }



    }

With this function, it works perfect, but that is having the images in the drawable folder, and what you want or what it is that you take the image of the json url, traide with glide

private void setWallpaper() {

        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.cochinito);

        WallpaperManager manager = WallpaperManager.getInstance(getApplicationContext());



        try {

            manager.setBitmap(bitmap);

            Toast.makeText(this, "Listo", Toast.LENGTH_SHORT).show();



        } catch (IOException e) {

            Toast.makeText(this, "error", Toast.LENGTH_SHORT).show();

        }

    }

In conclusion, what I need is that when you click on the button, the displayed image is set as wallpaper

As I can see, you are not using full path for decoding bitmap. You need to obtain full path name like:

String uri =  Environment.getExternalStorageDirectory().toString() + "/" + PHOTO_DIR  + "/test.jpg";

After that:

Bitmap bitmap = BitmapFactory.decodeFile(uri);

Reference