java - 我想在 Android Studio 中制作一个总统评论应用程序，其中包含每位总统的照片，但我不断收到 OutOfMemoryError

Question

我刚刚开始使用Android Studio，对java也有点陌生，所以请原谅低效的代码。

无论如何，当我单击应用程序上主要 Activity 上的按钮将用户带到我想要显示图像的 Activity 时，我的应用程序停止工作并抛出 OutOfMemoryError。

这是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));
        }
    });

}

这里是 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);
            }
        });

这是大部分错误日志:

/image/Wcphi.jpg

Answer 1

而不是将所有可绘制内容存储在数组中。实际上，您可以将资源 id 存储在数组中。

1. 将 private Drawable [] drawables = null; 替换为 private int[] drawableids

2. 将 drawables = new Drawable[]{...} 替换为 drawableids = new int[]{...}

   <

3. 替换

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

至

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

尝试按照上述步骤进行更改，然后重试。nullpointerException可能是由于您没有初始化drawableids数组或者您仍在使用drawables数组而不是drawableids引起的。