Android开发技巧——PagerAdapter的再次简单封装

这次再对内容为View的ViewPager的适配器PagerAdapter进行简单的封装，支持List数据和SparseArray的数据，带更新视图功能。

首先，先贴上最上面的抽象类代码：

/*
 * Date: 14-8-18
 * Project: Access-Control-V2
 */
package cn.irains.access_control_v2.common;

import android.support.v4.view.PagerAdapter;
import android.util.SparseArray;
import android.view.View;
import android.view.ViewGroup;

import java.util.List;

/**
 * 抽象的PagerAdapter实现类,封装了内容为View的公共操作.
 * Author: msdx ([email protected])
 * Time: 14-8-18 下午2:34
 */
public abstract class AbstractViewPagerAdapter extends PagerAdapter {
    protected SparseArray<View> mViews;

    public AbstractViewPagerAdapter() {
        mViews = new SparseArray<View>();
    }

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        View view = mViews.get(position);
        if (view == null) {
            view = newView(position);
            mViews.put(position, view);
        }
        container.addView(view);
        return view;
    }

    public abstract View newView(int position);

    public void notifyUpdateView(int position) {
        View view = updateView(mViews.get(position), position);
        mViews.put(position, view);
        notifyDataSetChanged();
    }

    public View updateView(View view, int position) {
        return view;
    }

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

}

接下来看数据为List的封装，代码如下：

/*
 * Date: 14-8-18
 * Project: Access-Control-V2
 */
package cn.irains.access_control_v2.common;

import android.view.View;

import java.util.List;

/**
 * 抽象的PagerAdapter实现类,封装了内容为View,数据为List类型的适配器实现.
 * Author: msdx ([email protected])
 * Time: 14-8-18 下午2:34
 */
public abstract class AbstractPagerListAdapter<T> extends AbstractViewPagerAdapter {
    protected List<T> mData;

    public AbstractPagerListAdapter(List<T> data) {
        mData = data;
    }

    @Override
    public int getCount() {
        return mData.size();
    }

    public abstract View newView(int position);

    public T getItem(int position) {
        return mData.get(position);
    }
}

同样，数据为SparseArray的适配器封装类代码与其相似，如下：

/*
 * Date: 14-8-18
 * Project: Access-Control-V2
 */
package cn.irains.access_control_v2.common;

import android.util.SparseArray;
import android.view.View;

/**
 * 抽象的PagerAdapter实现类,封装了内容为View,数据为SparseArray类型的适配器实现.
 * Author: msdx ([email protected])
 * Time: 14-8-18 下午2:34
 */
public abstract class AbstractPagerSparseAdapter<T> extends AbstractViewPagerAdapter {
    protected SparseArray<T> mData;

    public AbstractPagerSparseAdapter(SparseArray<T> data) {
        mData = data;
    }

    @Override
    public int getCount() {
        return mData.size();
    }

    public abstract View newView(int position);

    public T getItem(int position) {
        return mData.valueAt(position);
    }
}