java - 5000 毫秒后在 ImageView 中显示数组中的随机图像

Question

我有一个字符串数组，它在按下按钮后 5000 毫秒后在 TextView 中显示随机文本结果。我想要实现的是拥有一组图像而不是文本，因此希望在 5000 毫秒后在 ImageView 中显示随机图像。

public class MainActivity extends AppCompatActivity {
    private ImageView thumbPrint;
    private TextView result;
    private AnimationDrawable thumbAnimation;
    private String[] moodResults;
    private Runnable mRunnable;

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

        moodResults = new String[]{
            "result a",
            "result b",
            "result c",
            "result d",
            "result e",
            "result f"
        };

        thumbPrint = (ImageView)findViewById(R.id.thumbPrint);
        thumbPrint.setBackgroundResource(R.drawable.thumb_animation);
        thumbAnimation = (AnimationDrawable)thumbPrint.getBackground();

        result = (TextView)findViewById(R.id.resultText);

        thumbPrint.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                thumbAnimation.start();
                showResult();
                return true;
            }
        });
    }

    public void showResult(){
        mRunnable = new Runnable() {
            @Override
            public void run() {
                int rand = (int)(Math.random()* moodResults.length);
                result.setText(moodResults[rand]);
                //stop animation
                thumbAnimation.stop();
            }
        };

        Handler mHandler = new Handler();
        mHandler.postDelayed(mRunnable, 5000);
    }
}

Answer 1

这样实现:

这些变量在 MainActivity 中声明。它们可以在 onCreate()

中单独初始化

 final int[] imageIds= {
            R.drawable.image1, R.drawable.image2, ...}; // This is your array with resource id of each image
 Random r = new Random();
 Handler mHandler = new Handler();

这是 showResult() 的重构代码:

public void showResult(){
            mRunnable = new Runnable() {
                @Override
                public void run() {
                    int rand = (int)(Math.random()* moodResults.length);
                    result.setText(moodResults[rand]);
                    int randomInt = r.nextInt(imageIds.length);
                    thumbprint.setBackgroundResource(imageIds[randomInt]); //thumbprint is your Imageview
                    //stop animation
                    thumbAnimation.stop();
                    mHandler.postDelayed(mRunnable, 5000);//This causes hanlder to called again in 5 seconds
                }
            };

            mHandler.postDelayed(mRunnable, 5000); //Here handler is called the first time; the code in mRunnable will execute after 5 seconds 
        }