我有 Infinite ViewPager 应用程序，一切正常，但如果你快速滚动图像，你将面临图像滚动之间的滞后，它不流畅和快速，
任何克服这个问题的建议，所以最后我可以快速流畅地滚动它，
任何帮助将不胜感激，谢谢。
ImagePager.java
public class ImagePager extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
PagerAdapter adapter = new InfinitePagerAdapter(new ImagePagerAdapter(this, imageArra, stringArray));
ViewPager myPager = (ViewPager) findViewById(R.id.myimagepager);
myPager.setAdapter(adapter);
myPager.setCurrentItem(0);}
private int imageArra[] = { R.drawable.a, R.drawable.b, R.drawable.c, R.drawable.d, R.drawable.e,
R.drawable.f, R.drawable.g, R.drawable.h, R.drawable.i, R.drawable.j,
R.drawable.k, R.drawable.l, R.drawable.m, R.drawable.n, R.drawable.o};
private String[] stringArray = new String[] { "Image a", "Image b","Image c","Image d","Image e",
"Image f", "Image g","Image h","Image i","Image j",
"Image k", "Image l","Image m","Image n","Image o"};
}
ImagePagerAdapter.java
public class ImagePagerAdapter extends PagerAdapter {
Activity activity;
int imageArray[];
String[] stringArray;
public ImagePagerAdapter(Activity act, int[] imgArra, String[] stringArra) {
imageArray = imgArra;
activity = act;
stringArray = stringArra;
}
public int getCount() {
return imageArray.length;
}
public Object instantiateItem(View collection, int position) {
LayoutInflater inflater = (LayoutInflater)collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = inflater.inflate(R.layout.custom_pager, null);
ImageView im=(ImageView) layout.findViewById(R.id.myimage);
im.setImageResource(imageArray[position]);
TextView txt=(TextView) layout.findViewById(R.id.image_text);
txt.setText(stringArray[position]);
((ViewPager) collection).addView(layout, 0);
return layout;
}
@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
((ViewPager) arg0).removeView((View) arg2);
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == ((View) arg1);
}
@Override
public Parcelable saveState() {
return null;
}
}
InfinitePagerAdapter.java
public class InfinitePagerAdapter extends PagerAdapter {
private static final String TAG = "InfinitePagerAdapter";
private static final boolean DEBUG = true;
private PagerAdapter adapter;
public InfinitePagerAdapter(PagerAdapter adapter) {
this.adapter = adapter;
}
@Override
public int getCount() {
// warning: scrolling to very high values (1,000,000+) results in
// strange drawing behaviour
return Integer.MAX_VALUE;
}
/**
* @return the {@link #getCount()} result of the wrapped adapter
*/
public int getRealCount() {
return adapter.getCount();
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
int virtualPosition = position % getRealCount();
debug("instantiateItem: real position: " + position);
debug("instantiateItem: virtual position: " + virtualPosition);
// only expose virtual position to the inner adapter
return adapter.instantiateItem(container, virtualPosition);
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
int virtualPosition = position % getRealCount();
debug("destroyItem: real position: " + position);
debug("destroyItem: virtual position: " + virtualPosition);
// only expose virtual position to the inner adapter
adapter.destroyItem(container, virtualPosition, object);
}
/*
* Delegate rest of methods directly to the inner adapter.
*/
@Override
public void finishUpdate(ViewGroup container) {
adapter.finishUpdate(container);
}
@Override
public boolean isViewFromObject(View view, Object object) {
return adapter.isViewFromObject(view, object);
}
@Override
public void restoreState(Parcelable bundle, ClassLoader classLoader) {
adapter.restoreState(bundle, classLoader);
}
@Override
public Parcelable saveState() {
return adapter.saveState();
}
@Override
public void startUpdate(ViewGroup container) {
adapter.startUpdate(container);
}
/*
* End delegation
*/
private void debug(String message) {
if (DEBUG) {
Log.d(TAG, message);
}
}
}
InfiniteViewPager.java
public class InfiniteViewPager extends ViewPager {
public InfiniteViewPager(Context context) {
super(context);
}
public InfiniteViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public void setAdapter(PagerAdapter adapter) {
super.setAdapter(adapter);
// offset first element so that we can scroll to the left
setCurrentItem(0);
}
@Override
public void setCurrentItem(int item) {
// offset the current item to ensure there is space to scroll
item = getOffsetAmount() + (item % getAdapter().getCount());
super.setCurrentItem(item);
}
private int getOffsetAmount() {
if (getAdapter() instanceof InfinitePagerAdapter) {
InfinitePagerAdapter infAdapter = (InfinitePagerAdapter) getAdapter();
// allow for 100 back cycles from the beginning
// should be enough to create an illusion of infinity
// warning: scrolling to very high values (1,000,000+) results in
// strange drawing behaviour
return infAdapter.getRealCount() * 100;
} else {
return 0;
}
}
}
custom_pager.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#FFDAB9"
android:gravity="center_horizontal">
<ImageView android:id="@+id/myimage"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_margin="5dp"
android:layout_weight="2" />
<TextView android:id="@+id/image_text"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:textColor="#B22222"
android:gravity="center"
android:textSize="20sp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:layout_margin="10dp"
android:layout_weight="1"
android:background="@drawable/border" />
</LinearLayout>