How to save ImageResource from ImageSwitcher when rotating screen

Question

I can't find a simple solution to avoid my ImageSwitcher change the ImageResource displayed when I rotate the screen. I tried and tried to write different things in onSaveInstanceState() and onRestoreInstanceState(), but I couldn't find anything that works.

How can I achieve something like this (pure pseudo-code):

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {

    // Save UI state changes to the savedInstanceState.
    // This bundle will be passed to onCreate if the process is
    // killed and restarted.
    int picNum = imageSwitcher.getImageResource();

    savedInstanceState.putInt("picNum", picNum);
    // etc.

    super.onSaveInstanceState(savedInstanceState);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {

    super.onRestoreInstanceState(savedInstanceState);

    // Restore UI state from the savedInstanceState.
    // This bundle has also been passed to onCreate.
    Int picNum =  savedInstanceState.getString("picNum");
    imageSwitcher.setImageResource(picNum);
}

I don't know exactly the displayed image name, so I have to find it everytime (everytime the ImageSwitcher displays a random image from "raw" folder). A simplified version of the code I'm using is this:

rawClass = R.raw.class;

fields = rawClass.getFields();

rand = new Random();

rndInt = rand.nextInt(fields.length);

resID = fields[rndInt].getInt(rawClass);

imageSwitcher.setImageResource(resID);

Thank you in advance

Answer 1

I found a workaround:

I store the resId in on int[] and with that I can call it switcherImageView.setImageResource(imgArr[currentPhoto]);

after that I'm able to use it also in saveonSaveInstanceState() method:

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {

    // Save UI state changes to the savedInstanceState.
    int randInteger = rndInt;
    int[] saveArray = imgArr;
    int picNum = imgArr[currentPhoto];

    savedInstanceState.putInt("picNum", picNum);
    savedInstanceState.putInt("randInteger", randInteger);
    savedInstanceState.putIntArray("picArr", saveArray);
    // etc.

    super.onSaveInstanceState(savedInstanceState);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {

    super.onRestoreInstanceState(savedInstanceState);

    // Restore UI state from the savedInstanceState.
    // This bundle has also been passed to onCreate.
    int[] picArr =  savedInstanceState.getIntArray("picArr");
    int picNum =  savedInstanceState.getInt("picNum");
    imgArr = picArr;
    imageSwitcher.setImageResource(picNum);
}

Now when I rotate screen everything is fine, I can have the same pic in the ImageSlider But when I click again, it doesn't matter at what index it is, it will start from the very beginning of the array imgArr[0].

EDIT Found the final solution! :) I had to store the index obviously :doh!:

so I wrote: int currentPhoto= indexNumber; savedInstanceState.putInt("currentPhoto", currentPhoto); in onSaveInstanceState() method and

int photoCurrent =  savedInstanceState.getInt("currentPhoto");

in OnRestoreIntanceState() method.

Everything works now!

Answer 2

You can also put the following line in your Manifest file.

        android:configChanges="keyboardHidden|orientation|screenSize"/>