How to programmatically change the background image of an Android Activity

Question

I have been able to change colour of an activity background (see this post). Now a requirement is to do the same with background image. I mean I can click a button, select an option and change the current Activity background image to the new one. Here is what I have done: ``` private SharedPreferences prefs; private static final String SELECTED_ITEM = "SelectedItem"; private Editor sharedPrefEditor; btnchangeColor = (ImageButton) findViewById(R.id.btnchangeColor); btnchangeColor.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final CharSequence[] items={getString(R.string.default),getString(R.string.pix1), getString(R.string.pix2))}; AlertDialog.Builder builder = new AlertDialog.Builder( ContentView.this); builder.setTitle((getResources().getString(R.string.color_switch))); builder.setPositiveButton((R.string.ok), new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }); builder.setSingleCho…

Accepted Answer

When you are setting background after selecting from `Dialog` then you are getting the resource id `R.drawable.pix2` and retrieving the `BitmapDrawable` as follows...

```
wvContent.setBackgroundColor(0);
BitmapDrawable bg = (BitmapDrawable)getResources().getDrawable(R.drawable.pix2);
bg.setTileModeXY(TileMode.REPEAT, TileMode.REPEAT);
wvContent.setBackgroundDrawable(bg);                    
bg_color=R.drawable.pix2;
```

But in `onCreate()` method you are just passing the resource id as below...

```
wvContent.setBackgroundColor(getSelectedItem());
```

where, `getSelectedItem()` returns an `int` value which is a resource id.

Now, set background drawable as follows in `onCreate()` method...

```
wvContent.setBackgroundColor(0);
BitmapDrawable bg = (BitmapDrawable)getResources().getDrawable(getSelectedItem());
bg.setTileModeXY(TileMode.REPEAT, TileMode.REPEAT);
wvContent.setBackgroundDrawable(bg);
```

You can update background from SDCard as follows...

```
    String pathName = Environment.getExternalStorageDirectory().getPath() + "/folder/" + "image.jpg";
    Resources res = getResources(pathName);
    Bitmap bitmap = BitmapFactory.decodeFile(pathName);
    BitmapDrawable backgroundDrawable = new BitmapDrawable(res, bitmap);
    wvContent.setBackgroundDrawable(backgroundDrawable);
```

How to programmatically change the background image of an Android Activity

Solution

Problem

Related problems