RecyclerView通用適配器的實現

分析

• 我們需要在RecyclerViewAdapter內部維持一個數據集合的引用
• 需要實現Item的點擊事件，包括短按和長按，并需要向外部提供設置監聽器的方法
• 這個適配器必須通用，所以應該是泛型的，并且ViewHolder也是通用的，可以采用SparseArray維持View的所有集合
• 在RecyclerViewAdapter內部需要實現數據的綁定（抽象方法，延遲到子類實現），監聽器的綁定
</ul>

編寫監聽器

分為短按事件和長按事件

• 短按監聽器
</ul>

package cn.edu.zafu.base.adapter.listener;

import android.view.View;
/**

Created by lizhangqu on 2015/6/3.
*/
public interface OnItemClickListener<T> {
 void onClick(View view, T item);
}</pre>


長按監聽器 

package cn.edu.zafu.base.adapter.listener;

import android.view.View;
/**

Created by lizhangqu on 2015/6/3.
*/
public interface OnItemLongClickListener<T> {
 void onLongClick(View view, T item);
}</pre>

編寫通用適配器 

設置監聽器 

package cn.edu.zafu.base.adapter;

import android.support.v7.widget.RecyclerView;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.List;
import cn.edu.zafu.base.adapter.listener.OnItemClickListener;
import cn.edu.zafu.base.adapter.listener.OnItemLongClickListener;
/**

this is a BaseAdapter for RecyclerView
author lizhangqu
version 1.0
date 2015/6/3.
*/
public abstract class BaseRecyclerViewAdapter<T, VH extends BaseRecyclerViewAdapter.SparseArrayViewHolder> extends RecyclerView.Adapter<VH> {
/**

click listener
*/
protected OnItemClickListener mOnItemClickListener;
/**
long click listener
*/
protected OnItemLongClickListener mOnItemLongClickListener;
/**

set a long click listener
*
@param onItemLongClickListener
*/
public void setOnItemLongClickListener(OnItemLongClickListener onItemLongClickListener) {
 mOnItemLongClickListener = onItemLongClickListener;
}
/**

set a click listener
*
@param onItemClickListener
*/
public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
 mOnItemClickListener = onItemClickListener;
}



}</pre>


編寫構造方法，將數據集合進行賦值 
</ul>

    /**


 * data
 */
protected List<T> mList;

/**
 * @param list the datas to attach the adapter
 */
public BaseRecyclerViewAdapter(List<T> list) {
    mList = list;
}</pre><br />

實現幾個必要的方法，比如獲得Item以及覆寫getItemCount方法 

/**


get a item by index
*
@param position
@return
*/
protected T getItem(int position) {
 return mList.get(position);
}

@Override
public int getItemCount() {
    return mList.size();
}</pre>


實現將布局文件映射成View的方法 
</ul>

  /**


 * inflate a view by viewgroup ,id ,etc
 *
 * @param viewGroup
 * @param layoutId
 * @return
 */
protected View inflateItemView(ViewGroup viewGroup, int layoutId) {
    return inflateItemView(viewGroup, layoutId, false);
}

/**
 * inflate a view by viewgroup ,id ,etc
 *
 * @param viewGroup
 * @param layoutId
 * @param attach
 * @return
 */
protected View inflateItemView(ViewGroup viewGroup, int layoutId, boolean attach) {
    return LayoutInflater.from(viewGroup.getContext()).inflate(layoutId, viewGroup, attach);
}</pre><br />

實現onBindViewHolder方法，這一步很重要，將具體實現抽取到兩個方法中去實現，bindDataToItemView是一個抽象方法，延遲到子類實現，bindItemViewClickListener方法設置監聽器 
 /**


 * a final function to avoid you override
 * use template design pattern
 *
 * @param vh
 * @param position
 */
@Override
public final void onBindViewHolder(VH vh, int position) {
    final T item = getItem(position);
    bindDataToItemView(vh, item);
    bindItemViewClickListener(vh, item);
}

/**
 * bind data to itemview
 *
 * @param vh   viewholder
 * @param item item
 */
protected abstract void bindDataToItemView(VH vh, T item);
/**
 * bind click listner to itemview
 *
 * @param vh   viewholder
 * @param item item
 */
protected final void bindItemViewClickListener(VH vh, final T item) {
    if (mOnItemClickListener != null) {
        vh.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mOnItemClickListener.onClick(view, item);
            }
        });
    }
    if (mOnItemLongClickListener != null) {
        vh.itemView.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                mOnItemLongClickListener.onLongClick(v, item);
                return true;
            }
        });
    }
}</pre><br />


實現通用ViewHolder，內部使用SparseArray維持View對象 
</ul>

    public static class SparseArrayViewHolder extends RecyclerView.ViewHolder {
        private final SparseArray<View> views;


    public SparseArrayViewHolder(View itemView) {
        super(itemView);
        views = new SparseArray<View>();
    }

    public <T extends View> T getView(int id) {
        View view = views.get(id);
        if (view == null) {
            view = itemView.findViewById(id);
            views.put(id, view);
        }
        return (T) view;
    }
}</pre><br />

內部實現了一個泛型的getView方法，其作用就是將View緩存至SparseArray中去 


實現通用ViewHolder的一些屬性設置方法，采用鏈式調用，返回this對象 
</ul>

      public SparseArrayViewHolder setText(int viewId, String value) {
            TextView view = getView(viewId);
            view.setText(value);
            return SparseArrayViewHolder.this;
        }


    public SparseArrayViewHolder setTextColor(int viewId, int textColor) {
        TextView view = getView(viewId);
        view.setTextColor(textColor);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setImageResource(int viewId, int imageResId) {
        ImageView view = getView(viewId);
        view.setImageResource(imageResId);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setBackgroundColor(int viewId, int color) {
        View view = getView(viewId);
        view.setBackgroundColor(color);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setBackgroundResource(int viewId, int backgroundRes) {
        View view = getView(viewId);
        view.setBackgroundResource(backgroundRes);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setVisible(int viewId, boolean visible) {
        View view = getView(viewId);
        view.setVisibility(visible ? View.VISIBLE : View.GONE);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setOnClickListener(int viewId, View.OnClickListener listener) {
        View view = getView(viewId);
        view.setOnClickListener(listener);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setOnTouchListener(int viewId, View.OnTouchListener listener) {
        View view = getView(viewId);
        view.setOnTouchListener(listener);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setOnLongClickListener(int viewId, View.OnLongClickListener listener) {
        View view = getView(viewId);
        view.setOnLongClickListener(listener);
        return SparseArrayViewHolder.this;
    }

    public SparseArrayViewHolder setTag(int viewId, Object tag) {
        View view = getView(viewId);
        view.setTag(tag);
        return SparseArrayViewHolder.this;
    }</pre><br />

源碼 


參見github地址：https://github.com/lizhangqu 
</ul>
來自：http://blog.csdn.net/sbsujjbcy/article/details/46480885