我想在Android Studio中制作一个总统审查应用程序，其中包含每个总统的照片，但是我一直在收到OutOfMemoryError

Question

I have just started Android Studio and am also a little new to java, so please excuse the inefficient code.

Anyway, when I click on the button on the main activity on my app to take the user to the activity that I want to display the images, my app stops working and it throws an OutOfMemoryError.

Here is MainActivty.java:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button presidentQuizButton = (Button) findViewById(R.id.presidentQuizButton);
    Button reviewPresidentsButton = (Button) findViewById(R.id.reviewPresidentsButton);

    presidentQuizButton.setOnClickListener(new Button.OnClickListener(){
        public void onClick(View v){
            //when button is clicked, do something
        }
    });
    reviewPresidentsButton.setOnClickListener(new Button.OnClickListener(){
        public void onClick(View v){
            //when button is clicked, do something
            startActivity(new Intent(MainActivity.this, presidentReviewActivity.class));
        }
    });

}

Here is presidentReviewActivity.java:

ImageView imageView;
    public int presidentNumber = 0;

    private Drawable drawable;
    private Drawable [] drawables = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_president_review);

        Button menuButton = (Button) findViewById(R.id.menuButton);
        Button nextButton = (Button) findViewById(R.id.nextButton);
        Button backButton = (Button) findViewById(R.id.backButton);

        drawables = new Drawable[]{
                getResources().getDrawable(R.drawable.president1),
                getResources().getDrawable(R.drawable.president2),
                getResources().getDrawable(R.drawable.president3),
                getResources().getDrawable(R.drawable.president4),
                getResources().getDrawable(R.drawable.president5),
                getResources().getDrawable(R.drawable.president6),
                getResources().getDrawable(R.drawable.president7),
                getResources().getDrawable(R.drawable.president8),
                getResources().getDrawable(R.drawable.president9),
                getResources().getDrawable(R.drawable.president10),
                getResources().getDrawable(R.drawable.president11),
                getResources().getDrawable(R.drawable.president12),
                getResources().getDrawable(R.drawable.president13),
                getResources().getDrawable(R.drawable.president14),
                getResources().getDrawable(R.drawable.president15),
                getResources().getDrawable(R.drawable.president16),
                getResources().getDrawable(R.drawable.president17),
                getResources().getDrawable(R.drawable.president18),
                getResources().getDrawable(R.drawable.president19),
                getResources().getDrawable(R.drawable.president20),
                getResources().getDrawable(R.drawable.president21),
                getResources().getDrawable(R.drawable.president22),
                getResources().getDrawable(R.drawable.president23),
                getResources().getDrawable(R.drawable.president24),
                getResources().getDrawable(R.drawable.president25),
                getResources().getDrawable(R.drawable.president26),
                getResources().getDrawable(R.drawable.president27),
                getResources().getDrawable(R.drawable.president28),
                getResources().getDrawable(R.drawable.president29),
                getResources().getDrawable(R.drawable.president30),
                getResources().getDrawable(R.drawable.president31),
                getResources().getDrawable(R.drawable.president32),
                getResources().getDrawable(R.drawable.president33),
                getResources().getDrawable(R.drawable.president34),
                getResources().getDrawable(R.drawable.president35),
                getResources().getDrawable(R.drawable.president36),
                getResources().getDrawable(R.drawable.president37),
                getResources().getDrawable(R.drawable.president38),
                getResources().getDrawable(R.drawable.president39),
                getResources().getDrawable(R.drawable.president40),
                getResources().getDrawable(R.drawable.president41),
                getResources().getDrawable(R.drawable.president42),
                getResources().getDrawable(R.drawable.president43),
                getResources().getDrawable(R.drawable.president44),
        };

        menuButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                finish();
            }
        });

        nextButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                presidentNumber++;
                drawable = drawables[presidentNumber];
                imageView.setImageDrawable(drawable);
            }
        });

And here is most of the error log:

http://imgur.com/xzFfPrq

Answer 1

Instead of store all the drawable content in an array. You can actually just store the resource id in a array.

1. replace private Drawable [] drawables = null; with private int[] drawableids

2. replace drawables = new Drawable[]{...} to drawableids = new int[]{...}

3. replace

    drawable = drawables[presidentNumber]; imageView.setImageDrawable(drawable); 

to

drawable = getResource().getDrawable(drawableids[presidentNumber]);
imageView.setImageDrawable(drawable);

Try to change as above steps and try again. The nullpointerexception may be caused by you did not init the drawableids array or you are still using the drawables array instead of drawableids.

Answer 2

您正尝试将大尺寸图像直接加载到内存中，这会导致内存不足异常，对此问题进行了详细讨论，并且在开发人员站点中提供了一个不错的解决方案