Java ViewPager/PagerAdapter：更改字符串的值 我有一个youtube播放列表：

或

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如果我正确理解了您的问题，您可以在onPageChangeListener中更改类级别变量playlist

int position

在onPageScrolled中是第一个显示项目的索引

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作为旁注，所有大写字母都应保留为常量。任何可以在代码中更改的变量都应该以小写字母开头

谢谢！因此，如果我理解正确，我需要使用诸如：@Override public void on pagescrolled（int-position，float-arg1，int-arg2）{if（position>oldPos）{//向右移动}或者if（position@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.home); final ActionBar actionBar = getActionBar(); ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager); viewPager.setAdapter(adapter); actionBar.setCustomView(R.layout.actionbar_custom_view_home); actionBar.setDisplayShowTitleEnabled(false); actionBar.setDisplayShowCustomEnabled(true); drawerListViewItems = getResources().getStringArray(R.array.items); drawerListView = (ListView) findViewById(R.id.left_drawer); drawerListView.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_listview_item, drawerListViewItems)); drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); actionBarDrawerToggle = new ActionBarDrawerToggle(this, /* host Activity */ drawerLayout, /* DrawerLayout object */ R.drawable.ic_drawer, /* nav drawer icon to replace 'Up' caret */ R.string.drawer_open, /* "open drawer" description */ R.string.drawer_close /* "close drawer" description */ ); drawerLayout.setDrawerListener(actionBarDrawerToggle); getActionBar().setDisplayHomeAsUpEnabled(true); drawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START); listView = (VideosListView) findViewById(R.id.videosListView); listView.setOnVideoClickListener(this); new GetYouTubeUserVideosTask(responseHandler, PLAYLIST).execute(); }

    private class ImagePagerAdapter extends PagerAdapter {
        public ImagePagerAdapter(Activity act, int[] mImages,
                String[] stringArra) {
            imageArray = mImages;
            activity = act;
            stringArray = stringArra;
        }

        public ImagePagerAdapter() {
            super();
            // setOnPageChangeListener(mPageChangeListener);
        }

        private int[] mImages = new int[] { R.drawable.selstation_up_btn,
                R.drawable.classical_up_btn, R.drawable.country_up_btn,
                R.drawable.dance_up_btn, R.drawable.hiphop_up_btn,
                R.drawable.island_up_btn, R.drawable.latin_up_btn,
                R.drawable.pop_up_btn, R.drawable.samba_up_btn };

        private String[] stringArray = new String[] { "vevo",
                "TheMozARTGROUP‎", "TimMcGrawVEVO‎", "TiestoVEVO‎",
        "EminemVEVO‎" };

        @Override
        public int getCount() {
            return mImages.length;
        }

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

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            Context context = Home.this;
            ImageView imageView = new ImageView(context);
            imageView.setScaleType(ScaleType.FIT_XY);
            imageView.setImageResource(mImages[position]);
            ((ViewPager) container).addView(imageView, 0);
            return imageView;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            ((ViewPager) container).removeView((ImageView) object);
        }

        private final ViewPager.SimpleOnPageChangeListener mPageChangeListener = new ViewPager.SimpleOnPageChangeListener() {

            @Override
            public void onPageSelected(final int position) {
                onTabChanged(mPager.getAdapter(), mCurrentTabPosition, position);
                mCurrentTabPosition = position;

            }
        };

        public View getView(int position, View convertView, ViewGroup parent) {
            View vi=convertView;
            if (convertView == null) {
                convertView = LayoutInflater.from(context)
                  .inflate(R.layout.home, parent, false);
            }

            ImageView imageView = new ImageView(context);
            ImageView imageView = (ImageView)vi.findViewById(R.drawable.selstation_up_btn);
            imageView.setImageResource(imageView.getImage());

            return convertView;
        }

        protected void onTabChanged(final PagerAdapter adapter,
                final int oldPosition, final int newPosition) {
            // Calc if swipe was left to right, or right to left
            if (oldPosition > newPosition) {
                // left to right
            } else {
                // right to left

                View vg = findViewById(R.layout.home);
                vg.invalidate();
            }
            final ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);

            viewPager.setOnPageChangeListener(new OnPageChangeListener() {

                int oldPos = viewPager.getCurrentItem();

                @Override
                public void onPageScrolled(int position, float arg1, int arg2) {

                    if (position > oldPos) {
                        // Moving to the right

                    } else if (position < oldPos) {
                        // Moving to the Left

                        View vg = findViewById(R.layout.home);
                        vg.invalidate();
                    }
                }

                @Override
                public void onPageScrollStateChanged(int arg0) {
                    // TODO Auto-generated method stub

                }

                @Override
                public void onPageSelected(int arg0) {
                    // TODO Auto-generated method stub

                }

            });

        }
    }
    }

if R.drawable.classical_up_btn {

String PLAYLIST = "TheMozARTGROUP‎";

}

 if R.drawable.country_up_btn {

   String PLAYLIST = "TimMcGrawVEVO‎";
}