我使用以下示例设置了一个简单的 OnPageChangeListener:
然而,它似乎从未这样做,这导致viewPager无法正常工作。 有什么建议吗?
Android SimpleOnPageChangeListener - Determine swipe direction
然而,当我执行代码并滑动 viewpager 时,我期望会调用以下行:public void onPageSelected(int position) {
然而,它似乎从未这样做,这导致viewPager无法正常工作。 有什么建议吗?
public class Home extends YouTubeBaseActivity implements VideoClickListener {
...
private int mCurrentTabPosition = NO_CURRENT_POSITION;
private static final int NO_CURRENT_POSITION = -1;
private ViewPager mPager;
...
int imageArray[];
String[] stringArray;
private OnPageChangeListener mPageChangeListener;
ImagePagerAdapter adapter = new ImagePagerAdapter();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
final ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
viewPager.setAdapter(adapter);
...
setOnPageChangeListener(mPageChangeListener);
mPageChangeListener = new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
onTabChanged(mPager.getAdapter(), mCurrentTabPosition, position);
position = mCurrentTabPosition;
int oldPos = viewPager.getCurrentItem();
if (position > oldPos) {
System.out.print(position);
// Moving to the right
String playlist = "TheMozARTGROUP";
new GetYouTubeUserVideosTask(responseHandler, playlist)
.execute();
View vg = findViewById(R.layout.home);
vg.invalidate();
} else if (position < oldPos) {
// Moving to the Left
System.out.print(position);
String playlist = "TheMozARTGROUP";
new GetYouTubeUserVideosTask(responseHandler, playlist)
.execute();
View vg = findViewById(R.layout.home);
vg.invalidate();
}
viewPager.setOnPageChangeListener(mPageChangeListener);
}
private void onTabChanged(PagerAdapter adapter,
int mCurrentTabPosition, int position) {
// TODO Auto-generated method stub
}
};
}
private void setOnPageChangeListener(
OnPageChangeListener mPageChangeListener2) {
// TODO Auto-generated method stub
}
...
private class ImagePagerAdapter extends PagerAdapter {
public ImagePagerAdapter(Activity act, int[] mImages,
String[] stringArra) {
imageArray = mImages;
activity = act;
stringArray = stringArra;
}
public ImagePagerAdapter() {
super();
}
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);
}
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
}
final ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
}
}
}
XML:
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="wrap_content"
android:layout_height="fill_parent" />