Android之实现RTL的ViewPager

1 问题

如何实现RTL的ViewPager，就是滑动方向和我们之前滑动的方向相反，比如一般，我们用ViewPager滑动4个图片，依次顺序是

1 2 3 4 ，我们在页面1的时候，我们一般都是习惯向左滑动到2，现在需要实现手指向右滑动到2.

2 解决办法

1）我们可以使用ViewPager2,这个是可以支持的，不熟悉可以去官网看介绍。

https://developer.android.google.cn/jetpack/androidx/releases/viewpager2

2）如果我们使用普通的viewPager,我们可以把viewPager和page旋转180度。

            viewPager.setRotationY(180);            viewPager.setPageTransformer(false, new ViewPager.PageTransformer() {                @Override                public void transformPage(@NonNull View page, float position) {                    page.setRotationY(180);                }

优点：简单适合适配Android9.0以上的手机这个方法非常好

缺点：就是在Android9.0以上的手机上滑动效果不是很敏感，高版本手机适配还是不要采取了。

3）我们使用第三方开源项目（rtl-viewpager）

地址：https://github.com/duolingo/rtl-viewpager

优点：左滑右滑都可以，而且安卓手机版本兼容性也比较好。

缺点：但是就是点击图片预览的放大和缩小不怎么好使，效果不过。

我们可以直接把这2个类拷贝到我们项目也行，可以方便改代码

RtlViewPager.java 文件，onRtlPropertiesChanged函数有判断是否是RTL布局，如果觉得判断不准确，可以用的我的这篇博客

修改来判断Android之如何判断当前是阿拉伯布局的方法

package com.duolingo.open.rtlviewpager;import android.content.Context;import android.os.Parcel;import android.os.Parcelable;import android.util.AttributeSet;import android.view.View;import android.view.ViewGroup;import androidx.annotation.NonNull;import androidx.core.view.ViewCompat;import androidx.viewpager.widget.PagerAdapter;import androidx.viewpager.widget.ViewPager;import java.util.HashMap;public class RtlViewPager extends ViewPager {    private final HashMap mPageChangeListeners = new HashMap<>();    private int mLayoutDirection = ViewCompat.LAYOUT_DIRECTION_LTR;    public RtlViewPager(Context context) {        super(context);    }    public RtlViewPager(Context context, AttributeSet attrs) {        super(context, attrs);    }    @Override    public void onRtlPropertiesChanged(int layoutDirection) {        super.onRtlPropertiesChanged(layoutDirection);        int viewCompatLayoutDirection = layoutDirection == View.LAYOUT_DIRECTION_RTL ? ViewCompat.LAYOUT_DIRECTION_RTL : ViewCompat.LAYOUT_DIRECTION_LTR;        if (viewCompatLayoutDirection != mLayoutDirection) {            PagerAdapter adapter = super.getAdapter();            int position = 0;            if (adapter != null) {                position = getCurrentItem();            }            mLayoutDirection = viewCompatLayoutDirection;            if (adapter != null) {                adapter.notifyDataSetChanged();                setCurrentItem(position);            }        }    }    @Override    public void setAdapter(PagerAdapter adapter) {        if (adapter != null) {            adapter = new ReversingAdapter(adapter);        }        super.setAdapter(adapter);        setCurrentItem(0);    }    @Override    public PagerAdapter getAdapter() {        ReversingAdapter adapter = (ReversingAdapter) super.getAdapter();        return adapter == null ? null : adapter.getDelegate();    }    private boolean isRtl() {        return mLayoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL;    }    @Override    public int getCurrentItem() {        int item = super.getCurrentItem();        PagerAdapter adapter = super.getAdapter();        if (adapter != null && isRtl()) {            item = adapter.getCount() - item - 1;        }        return item;    }    @Override    public void setCurrentItem(int position, boolean smoothScroll) {        PagerAdapter adapter = super.getAdapter();        if (adapter != null && isRtl()) {            position = adapter.getCount() - position - 1;        }        super.setCurrentItem(position, smoothScroll);    }    @Override    public void setCurrentItem(int position) {        PagerAdapter adapter = super.getAdapter();        if (adapter != null && isRtl()) {            position = adapter.getCount() - position - 1;        }        super.setCurrentItem(position);    }    @Deprecated    @Override    public void setOnPageChangeListener(@NonNull ViewPager.OnPageChangeListener listener) {        super.setOnPageChangeListener(new ReversingOnPageChangeListener(listener));    }    @Override    public Parcelable onSaveInstanceState() {        Parcelable superState = super.onSaveInstanceState();        return new SavedState(superState, mLayoutDirection);    }    @Override    public void onRestoreInstanceState(Parcelable state) {        if (!(state instanceof SavedState)) {            super.onRestoreInstanceState(state);            return;        }        SavedState ss = (SavedState) state;        mLayoutDirection = ss.mLayoutDirection;        super.onRestoreInstanceState(ss.mViewPagerSavedState);    }    public static class SavedState implements Parcelable {        private final Parcelable mViewPagerSavedState;        private final int mLayoutDirection;        private SavedState(Parcelable viewPagerSavedState, int layoutDirection) {            mViewPagerSavedState = viewPagerSavedState;            mLayoutDirection = layoutDirection;        }        private SavedState(Parcel in, ClassLoader loader) {            if (loader == null) {                loader = getClass().getClassLoader();            }            mViewPagerSavedState = in.readParcelable(loader);            mLayoutDirection = in.readInt();        }        @Override        public int describeContents() {            return 0;        }        @Override        public void writeToParcel(Parcel out, int flags) {            out.writeParcelable(mViewPagerSavedState, flags);            out.writeInt(mLayoutDirection);        }        // The `CREATOR` field is used to create the parcelable from a parcel, even though it is never referenced directly.        public static final Parcelable.ClassLoaderCreator CREATOR                = new Parcelable.ClassLoaderCreator() {            @Override            public SavedState createFromParcel(Parcel source) {                return createFromParcel(source, null);            }            @Override            public SavedState createFromParcel(Parcel source, ClassLoader loader) {                return new SavedState(source, loader);            }            @Override            public SavedState[] newArray(int size) {                return new SavedState[size];            }        };    }    @Override    public void addOnPageChangeListener(@NonNull OnPageChangeListener listener) {        ReversingOnPageChangeListener reversingListener = new ReversingOnPageChangeListener(listener);        mPageChangeListeners.put(listener, reversingListener);        super.addOnPageChangeListener(reversingListener);    }    @Override    public void removeOnPageChangeListener(@NonNull OnPageChangeListener listener) {        ReversingOnPageChangeListener reverseListener = mPageChangeListeners.remove(listener);        if (reverseListener != null) {            super.removeOnPageChangeListener(reverseListener);        }    }    @Override    public void clearOnPageChangeListeners() {        super.clearOnPageChangeListeners();        mPageChangeListeners.clear();    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {            int height = 0;            for (int i = 0; i < getChildCount(); i++) {                View child = getChildAt(i);                child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));                int h = child.getMeasuredHeight();                if (h > height) {                    height = h;                }            }            heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);        }        super.onMeasure(widthMeasureSpec, heightMeasureSpec);    }    private class ReversingOnPageChangeListener implements OnPageChangeListener {        private final OnPageChangeListener mListener;        ReversingOnPageChangeListener(OnPageChangeListener listener) {            mListener = listener;        }        @Override        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {            // The documentation says that `getPageWidth(...)` returns the fraction of the _measured_ width that that page takes up.  However, the code seems to            // use the width so we will here too.            final int width = getWidth();            PagerAdapter adapter = RtlViewPager.super.getAdapter();            if (isRtl() && adapter != null) {                int count = adapter.getCount();                int remainingWidth = (int) (width * (1 - adapter.getPageWidth(position))) + positionOffsetPixels;                while (position < count && remainingWidth > 0) {                    position += 1;                    remainingWidth -= (int) (width * adapter.getPageWidth(position));                }                position = count - position - 1;                positionOffsetPixels = -remainingWidth;                positionOffset = positionOffsetPixels / (width * adapter.getPageWidth(position));            }            mListener.onPageScrolled(position, positionOffset, positionOffsetPixels);        }        @Override        public void onPageSelected(int position) {            PagerAdapter adapter = RtlViewPager.super.getAdapter();            if (isRtl() && adapter != null) {                position = adapter.getCount() - position - 1;            }            mListener.onPageSelected(position);        }        @Override        public void onPageScrollStateChanged(int state) {            mListener.onPageScrollStateChanged(state);        }    }    private class ReversingAdapter extends DelegatingPagerAdapter {        ReversingAdapter(@NonNull PagerAdapter adapter) {            super(adapter);        }        @Override        public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {            if (isRtl()) {                position = getCount() - position - 1;            }            super.destroyItem(container, position, object);        }        @Deprecated        @Override        public void destroyItem(@NonNull View container, int position, @NonNull Object object) {            if (isRtl()) {                position = getCount() - position - 1;            }            super.destroyItem(container, position, object);        }        @Override        public int getItemPosition(@NonNull Object object) {            int position = super.getItemPosition(object);            if (isRtl()) {                if (position == POSITION_UNCHANGED || position == POSITION_NONE) {                    // We can't accept POSITION_UNCHANGED when in RTL mode because adding items to the end of the collection adds them to the beginning of the                    // ViewPager.  Items whose positions do not change from the perspective of the wrapped adapter actually do change from the perspective of                    // the ViewPager.                    position = POSITION_NONE;                } else {                    position = getCount() - position - 1;                }            }            return position;        }        @Override        public CharSequence getPageTitle(int position) {            if (isRtl()) {                position = getCount() - position - 1;            }            return super.getPageTitle(position);        }        @Override        public float getPageWidth(int position) {            if (isRtl()) {                position = getCount() - position - 1;            }            return super.getPageWidth(position);        }        @Override        public @NonNull        Object instantiateItem(@NonNull ViewGroup container, int position) {            if (isRtl()) {                position = getCount() - position - 1;            }            return super.instantiateItem(container, position);        }        @Deprecated        @Override        public @NonNull        Object instantiateItem(@NonNull View container, int position) {            if (isRtl()) {                position = getCount() - position - 1;            }            return super.instantiateItem(container, position);        }        @Override        public void setPrimaryItem(@NonNull ViewGroup container, int position, @NonNull Object object) {            if (isRtl()) {                position = getCount() - position - 1;            }            super.setPrimaryItem(container, position, object);        }        @Deprecated        @Override        public void setPrimaryItem(@NonNull View container, int position, @NonNull Object object) {            if (isRtl()) {                position = getCount() - position - 1;            }            super.setPrimaryItem(container, position, object);        }    }}

DelegatingPagerAdapter.java文件

package com.duolingo.open.rtlviewpager;import android.database.DataSetObserver;import android.os.Parcelable;import android.view.View;import android.view.ViewGroup;import androidx.annotation.NonNull;import androidx.viewpager.widget.PagerAdapter;public class DelegatingPagerAdapter extends PagerAdapter {    private final PagerAdapter mDelegate;    DelegatingPagerAdapter(@NonNull final PagerAdapter delegate) {        this.mDelegate = delegate;        delegate.registerDataSetObserver(new MyDataSetObserver(this));    }    PagerAdapter getDelegate() {        return mDelegate;    }    @Override    public int getCount() {        return mDelegate.getCount();    }    @Override    public void startUpdate(@NonNull ViewGroup container) {        mDelegate.startUpdate(container);    }    @Override    public @NonNull    Object instantiateItem(@NonNull ViewGroup container, int position) {        return mDelegate.instantiateItem(container, position);    }    @Override    public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {        mDelegate.destroyItem(container, position, object);    }    @Override    public void setPrimaryItem(@NonNull ViewGroup container, int position, @NonNull Object object) {        mDelegate.setPrimaryItem(container, position, object);    }    @Override    public void finishUpdate(@NonNull ViewGroup container) {        mDelegate.finishUpdate(container);    }    @Deprecated    @Override    public void startUpdate(@NonNull View container) {        mDelegate.startUpdate(container);    }    @Deprecated    @Override    public @NonNull    Object instantiateItem(@NonNull View container, int position) {        return mDelegate.instantiateItem(container, position);    }    @Deprecated    @Override    public void destroyItem(@NonNull View container, int position, @NonNull Object object) {        mDelegate.destroyItem(container, position, object);    }    @Deprecated    @Override    public void setPrimaryItem(@NonNull View container, int position, @NonNull Object object) {        mDelegate.setPrimaryItem(container, position, object);    }    @Deprecated    @Override    public void finishUpdate(@NonNull View container) {        mDelegate.finishUpdate(container);    }    @Override    public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {        return mDelegate.isViewFromObject(view, object);    }    @Override    public Parcelable saveState() {        return mDelegate.saveState();    }    @Override    public void restoreState(Parcelable state, ClassLoader loader) {        mDelegate.restoreState(state, loader);    }    @Override    public int getItemPosition(@NonNull Object object) {        return mDelegate.getItemPosition(object);    }    @Override    public void notifyDataSetChanged() {        mDelegate.notifyDataSetChanged();    }    @Override    public void registerDataSetObserver(@NonNull DataSetObserver observer) {        mDelegate.registerDataSetObserver(observer);    }    @Override    public void unregisterDataSetObserver(@NonNull DataSetObserver observer) {        mDelegate.unregisterDataSetObserver(observer);    }    @Override    public CharSequence getPageTitle(int position) {        return mDelegate.getPageTitle(position);    }    @Override    public float getPageWidth(int position) {        return mDelegate.getPageWidth(position);    }    private void superNotifyDataSetChanged() {        super.notifyDataSetChanged();    }    private static class MyDataSetObserver extends DataSetObserver {        final DelegatingPagerAdapter mParent;        private MyDataSetObserver(DelegatingPagerAdapter mParent) {            this.mParent = mParent;        }        @Override        public void onChanged() {            if (mParent != null) {                mParent.superNotifyDataSetChanged();            }        }        @Override        public void onInvalidated() {            onChanged();        }    }}

4）我们使用第三方开源项目（RtlViewPager）

https://github.com/diego-gomez-olvera/RtlViewPager

优点：代码简单，左滑右滑都可以，而且安卓手机版本兼容性也比较好，点击图片放缩效果也非常棒，暂时用这个最优。

我们可以直接把这2个类拷贝到我们项目也行，可以方便改代码

RtlViewPager.java 文件，isRtl()函数判断是否是RTL布局，如果觉得判断不准确，可以用的我的这篇博客

修改来判断Android之如何判断当前是阿拉伯布局的方法

RtlViewPager.java

package com.booking.rtlviewpager;import android.content.Context;import android.database.DataSetObserver;import android.os.Parcel;import android.os.Parcelable;import android.support.annotation.NonNull;import android.support.annotation.Nullable;import android.support.v4.text.TextUtilsCompat;import android.support.v4.util.ArrayMap;import android.support.v4.view.PagerAdapter;import android.support.v4.view.ViewCompat;import android.support.v4.view.ViewPager;import android.util.AttributeSet;import android.view.ViewGroup;import java.util.Map;/** * ViewPager that reverses the items order in RTL locales. */public class RtlViewPager extends ViewPager {    @NonNull    private final Map reverseOnPageChangeListeners;    @Nullable    private DataSetObserver dataSetObserver;    private boolean suppressOnPageChangeListeners;    public RtlViewPager(Context context) {        super(context);        reverseOnPageChangeListeners = new ArrayMap<>(1);    }    public RtlViewPager(Context context, AttributeSet attrs) {        super(context, attrs);        reverseOnPageChangeListeners = new ArrayMap<>(1);    }    @Override    protected void onAttachedToWindow() {        super.onAttachedToWindow();        registerRtlDataSetObserver(super.getAdapter());    }    @Override    protected void onDetachedFromWindow() {        unregisterRtlDataSetObserver();        super.onDetachedFromWindow();    }    private void registerRtlDataSetObserver(PagerAdapter adapter) {        if (adapter instanceof ReverseAdapter && dataSetObserver == null) {            dataSetObserver = new RevalidateIndicesOnContentChange((ReverseAdapter) adapter);            adapter.registerDataSetObserver(dataSetObserver);            ((ReverseAdapter) adapter).revalidateIndices();        }    }    private void unregisterRtlDataSetObserver() {        final PagerAdapter adapter = super.getAdapter();        if (adapter instanceof ReverseAdapter && dataSetObserver != null) {            adapter.unregisterDataSetObserver(dataSetObserver);            dataSetObserver = null;        }    }    @Override    public void setCurrentItem(int item, boolean smoothScroll) {        super.setCurrentItem(convert(item), smoothScroll);    }    @Override    public void setCurrentItem(int item) {        super.setCurrentItem(convert(item));    }    @Override    public int getCurrentItem() {        return convert(super.getCurrentItem());    }    private int convert(int position) {        if (position >= 0 && isRtl()) {            return getAdapter() == null ? 0 : getAdapter().getCount() - position - 1;        } else {            return position;        }    }    @Nullable    @Override    public PagerAdapter getAdapter() {        final PagerAdapter adapter = super.getAdapter();        return adapter instanceof ReverseAdapter ? ((ReverseAdapter) adapter).getInnerAdapter() : adapter;    }    @Override    public void fakeDragBy(float xOffset) {        super.fakeDragBy(isRtl() ? xOffset : -xOffset);    }    @Override    public void setAdapter(@Nullable PagerAdapter adapter) {        unregisterRtlDataSetObserver();        final boolean rtlReady = adapter != null && isRtl();        if (rtlReady) {            adapter = new ReverseAdapter(adapter);            registerRtlDataSetObserver(adapter);        }        super.setAdapter(adapter);        if (rtlReady) {            setCurrentItemWithoutNotification(0);        }    }    private void setCurrentItemWithoutNotification(int index) {        suppressOnPageChangeListeners = true;        setCurrentItem(index, false);        suppressOnPageChangeListeners = false;    }    protected boolean isRtl() {        return TextUtilsCompat.getLayoutDirectionFromLocale(                getContext().getResources().getConfiguration().locale) == ViewCompat.LAYOUT_DIRECTION_RTL;    }    @Override    public void addOnPageChangeListener(@NonNull OnPageChangeListener listener) {        if (isRtl()) {            final ReverseOnPageChangeListener reverseListener = new ReverseOnPageChangeListener(listener);            reverseOnPageChangeListeners.put(listener, reverseListener);            listener = reverseListener;        }        super.addOnPageChangeListener(listener);    }    @Override    public void removeOnPageChangeListener(@NonNull OnPageChangeListener listener) {        if (isRtl()) {            listener = reverseOnPageChangeListeners.remove(listener);        }        super.removeOnPageChangeListener(listener);    }    @Override    public Parcelable onSaveInstanceState() {        return new SavedState(super.onSaveInstanceState(), getCurrentItem(), isRtl());    }    @Override    public void onRestoreInstanceState(Parcelable state) {        SavedState ss = (SavedState) state;        super.onRestoreInstanceState(ss.superState);        if (ss.isRTL != isRtl()) setCurrentItem(ss.position, false);    }    private class ReverseAdapter extends PagerAdapterWrapper {        private int lastCount;        public ReverseAdapter(@NonNull PagerAdapter adapter) {            super(adapter);            lastCount = adapter.getCount();        }        @Override        public CharSequence getPageTitle(int position) {            return super.getPageTitle(reverse(position));        }        @Override        public float getPageWidth(int position) {            return super.getPageWidth(reverse(position));        }        @Override        public int getItemPosition(Object object) {            final int itemPosition = super.getItemPosition(object);            return itemPosition < 0 ? itemPosition : reverse(itemPosition);        }        @Override        public Object instantiateItem(ViewGroup container, int position) {            return super.instantiateItem(container, reverse(position));        }        @Override        public void destroyItem(ViewGroup container, int position, Object object) {            super.destroyItem(container, reverse(position), object);        }        @Override        public void setPrimaryItem(ViewGroup container, int position, Object object) {            super.setPrimaryItem(container, lastCount - position - 1, object);        }        private int reverse(int position) {            return getCount() - position - 1;        }        private void revalidateIndices() {            final int newCount = getCount();            if (newCount != lastCount) {                setCurrentItemWithoutNotification(Math.max(0, lastCount - 1));                lastCount = newCount;            }        }    }    private static class RevalidateIndicesOnContentChange extends DataSetObserver {        @NonNull        private final ReverseAdapter adapter;        private RevalidateIndicesOnContentChange(@NonNull ReverseAdapter adapter) {            this.adapter = adapter;        }        @Override        public void onChanged() {            super.onChanged();            adapter.revalidateIndices();        }    }    private class ReverseOnPageChangeListener implements OnPageChangeListener {        @NonNull        private final OnPageChangeListener original;        private int pagerPosition;        private ReverseOnPageChangeListener(@NonNull OnPageChangeListener original) {            this.original = original;            pagerPosition = -1;        }        @Override        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {            if (!suppressOnPageChangeListeners) {                if (positionOffset == 0f && positionOffsetPixels == 0) {                    pagerPosition = reverse(position);                } else {                    pagerPosition = reverse(position + 1);                }                original.onPageScrolled(pagerPosition, positionOffset > 0 ? 1f - positionOffset : positionOffset, positionOffsetPixels);            }        }        @Override        public void onPageSelected(int position) {            if (!suppressOnPageChangeListeners) {                original.onPageSelected(reverse(position));            }        }        @Override        public void onPageScrollStateChanged(int state) {            if (!suppressOnPageChangeListeners) {                original.onPageScrollStateChanged(state);            }        }        private int reverse(int position) {            final PagerAdapter adapter = getAdapter();            return adapter == null ? position : adapter.getCount() - position - 1;        }    }    public static class SavedState implements Parcelable {        Parcelable superState;        int position;        boolean isRTL;        public SavedState(Parcelable superState, int position, boolean isRTL) {            super();            this.superState = superState;            this.position = position;            this.isRTL = isRTL;        }        SavedState(Parcel in, ClassLoader loader) {            if (loader == null) {                loader = getClass().getClassLoader();            }            superState = in.readParcelable(loader);            position = in.readInt();            isRTL = in.readByte() != 0;        }        @Override        public void writeToParcel(Parcel out, int flags) {            out.writeParcelable(superState, flags);            out.writeInt(position);            out.writeByte(isRTL ? (byte) 1 : (byte) 0);        }        @Override        public int describeContents() {            return 0;        }        public static final ClassLoaderCreator CREATOR = new                ClassLoaderCreator() {            @Override            public SavedState createFromParcel(Parcel source, ClassLoader loader) {                return new SavedState(source, loader);            }            @Override            public SavedState createFromParcel(Parcel source) {                return new SavedState(source, null);            }            public SavedState[] newArray(int size) {                return new SavedState[size];            }        };    }}

PagerAdapterWrapper.java

package com.booking.rtlviewpager;import android.database.DataSetObserver;import android.os.Parcelable;import android.support.annotation.NonNull;import android.support.v4.view.PagerAdapter;import android.view.View;import android.view.ViewGroup;/** * PagerAdapter decorator. */class PagerAdapterWrapper extends PagerAdapter {    @NonNull    private final PagerAdapter adapter;    protected PagerAdapterWrapper(@NonNull PagerAdapter adapter) {        this.adapter = adapter;    }    @NonNull    public PagerAdapter getInnerAdapter() {        return adapter;    }    @Override    public int getCount() {        return adapter.getCount();    }    @Override    public boolean isViewFromObject(View view, Object object) {        return adapter.isViewFromObject(view, object);    }    @Override    public CharSequence getPageTitle(int position) {        return adapter.getPageTitle(position);    }    @Override    public float getPageWidth(int position) {        return adapter.getPageWidth(position);    }    @Override    public int getItemPosition(Object object) {        return adapter.getItemPosition(object);    }    @Override    public Object instantiateItem(ViewGroup container, int position) {        return adapter.instantiateItem(container, position);    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {        adapter.destroyItem(container, position, object);    }    @Override    public void setPrimaryItem(ViewGroup container, int position, Object object) {        adapter.setPrimaryItem(container, position, object);    }    @Override    public void notifyDataSetChanged() {        adapter.notifyDataSetChanged();    }    @Override    public void registerDataSetObserver(DataSetObserver observer) {        adapter.registerDataSetObserver(observer);    }    @Override    public void unregisterDataSetObserver(DataSetObserver observer) {        adapter.unregisterDataSetObserver(observer);    }    @Override    public Parcelable saveState() {        return adapter.saveState();    }    @Override    public void restoreState(Parcelable state, ClassLoader loader) {        adapter.restoreState(state, loader);    }    @Override    public void startUpdate(ViewGroup container) {        adapter.startUpdate(container);    }    @Override    public void finishUpdate(ViewGroup container) {        adapter.finishUpdate(container);    }}

1 问题

2 解决办法

更多相关文章

随机推荐