ListView适配器之增强版BaseAdapter

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以往我们要写一个ListView的适配器的时候，我们往往要先继承BaseAdapter，然后在重写很多方法，然后再在**getView(int position, View view, ViewGroup viewGroup)** 函数里面，写我们的itemView的逻辑，其实无非就是三点：

inflate 视图布局
绑定视图
绑定数据（也就是我们的视图的逻辑）
因此，这就是我下面要做的一些事情：把构造的关键步骤全部抽取成抽象函数，封装在父类当中，子类实现只需要在重写的方法里面实现就好了。

import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import java.util.List;/** * an Enhanced abstract BaseAdapter . * * Created by Tata on 15/7/7. */public abstract class AbstractBaseAdapter<T,V> extends BaseAdapter {    private LayoutInflater mInflater;    private List<T> mDatas;    private Context mContext;    public AbstractBaseAdapter(Context mContext) {        this.mContext = mContext;        mInflater = LayoutInflater.from(mContext);    }    @Override    public int getCount() {        return mDatas == null ? 0 : (mDatas.isEmpty() ? 0 : mDatas.size());    }    @Override    public T getItem(int i) {        return mDatas == null ? null : mDatas.get(i);    }    @Override    public long getItemId(int i) {        return 0;    }    public void setData(List<T> data) {        mDatas = data;        notifyDataSetChanged();    }    public void appendData(List<T> appendedData) {        if (mDatas != null)            mDatas.addAll(appendedData);        notifyDataSetChanged();    }    public void clearData() {        mDatas.clear();        notifyDataSetChanged();    }    @Override    public View getView(int position, View view, ViewGroup viewGroup) {         V viewHolder = null;        if (view == null) {            viewHolder = getViewHolder();            view = mInflater.inflate(getItemLayoutId(), null);            onCreateItemView(position, viewHolder, view);            view.setTag(viewHolder);        } else {            viewHolder = (V) view.getTag();        }        onCreateItemData(view, viewHolder, position);        return view;    }    /**     * Retrieve the current item layou id.     *     * @return     */    protected abstract int getItemLayoutId();    /**     * Retrieve an instance of ViewHolder which was inherited from baseViewHolder     *     * @return     */    protected abstract V getViewHolder();    /**     * Called when the item view was first created.     *     * @param position     * @param viewHolder     * @param view     */    protected abstract void onCreateItemView(int position, V viewHolder, View view);    /**     * Called when the item view was filled with data.     *     * @param view     * @param viewHolder     * @param position     */    protected abstract void onCreateItemData(View view, V viewHolder, int position);}

下面是一个demo：

import android.content.Context;import android.view.View;import android.widget.ImageView;import android.widget.TextView;/** * Created by Tata on 15/7/7. */public class DemoAdapter extends AbstractBaseAdapter<DemoAdapter.Info, DemoAdapter.ViewHolder> {    //the item layout resource id    private int layoutid = 0x001;    public DemoAdapter(Context mContext) {        super(mContext);    }    @Override    protected int getItemLayoutId() {        return layoutid;    }    @Override    protected ViewHolder getViewHolder() {        return new ViewHolder();    }    @Override    protected void onCreateItemView(int position, ViewHolder viewHolder, View view) {        viewHolder.icon = (ImageView) view.findViewById(000);        viewHolder.name = (TextView) view.findViewById(0000);    }    @Override    protected void onCreateItemData(View view, ViewHolder viewHolder, int position) {        viewHolder.icon.setImageResource(0);        viewHolder.name.setText("tata");    }    static class ViewHolder {        private TextView name;        private ImageView icon;    }    /**     * data-bean     */    class Info {        private String name;        private int resId;        public String getName() {            return name;        }        public void setName(String name) {            this.name = name;        }        public int getResId() {            return resId;        }        public void setResId(int resId) {            this.resId = resId;        }    }}

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