查看页：获取当前项目位置

Question

也许我可以使用ViewPager getCurrentItem（）来检索当前页面的索引，但是我如何在代码中使用它呢？

public class QuestionPagerAdapter extends PagerAdapter{

    public QuestionPagerAdapter(){
        super();

    }
    @Override
    public int getCount() {
        int qcount = QuestionPagerAdapter.q.getQuestionCount();
        return qcount;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == ((View) object);
    }

    @Override
    public Object instantiateItem(View collection, int pos) {
        LayoutInflater inflater = (LayoutInflater) collection.getContext()
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        View page = inflater.inflate(R.layout.page_quiz, null);

        TextView tv = (TextView)page.findViewById(R.id.questionText);

        QuizFetchTask fft = new QuizFetchTask(tv);
        fft.execute(pos);

            ((ViewPager) collection).addView(page, 0);
        return page;
    }


    @Override
    public void destroyItem(View collection, int position, Object view) {
        //Util.Log("destroying" + position);
        ((ViewPager) collection).removeView((View) view);
    }

}

Answer 1

您可能要查找的是viewpager.setonpageChangelistener

所以你可以这样做：

myViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int i, float v, int i2) {

            }

            @Override
            public void onPageSelected(int i) {
               fft.execute(i)
            }

            @Override
            public void onPageScrollStateChanged(int i) {

            }
        });

此外，我不确定当页面被选中时，您试图执行什么类型的任务，但首先取消前一个任务是有意义的..例如：

                @Override
                public void onPageSelected(int i) {
                   fft.cancel(true);
                   fft.execute(i)
                }