Android 對封裝RecyclerView.Adapter講解

首先先得知RecyclerView.Adapter有什麼方法，這樣才知道與ListView的BaseAdapter有什麼區別：

public class MyAdapter extends RecyclerView.Adapter {

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return null; // 返回創建一個ViewHolder
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        // 這裏是刷新Item
    }

    @Override
    public int getItemCount() {
        return 0; // 有多少個Item
    }

    @Override
    public int getItemViewType(int position) {
        return super.getItemViewType(position); // 返回位置position，item的類型
    }

    @Override
    public void registerAdapterDataObserver(RecyclerView.AdapterDataObserver observer) {
        super.registerAdapterDataObserver(observer);
        // 註冊監聽數據被刷新
    }

    @Override
    public void unregisterAdapterDataObserver(RecyclerView.AdapterDataObserver observer) {
        super.unregisterAdapterDataObserver(observer);
        // 移除監聽數據被刷新
    }
}

爲了處理onBindViewHolder和onBindViewHolder故定義二個抽象方法：

    /**
     * item佈局ID
     *
     * @param viewType 類別
     * @return item佈局ID
     */
    public abstract int getContentView(int viewType);

    /**
     * item刷新的回調
     *
     * @param holder   ViewHolder
     * @param object   Item數據對象
     * @param position 刷新的位置
     */
    public abstract void onInitView(RecyclerHolder holder, T object, int position);

在開發中，Adapter的數據都用List來處理的，所以把RecyclerAdatper封裝成泛形：

package com.recycler.lib;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.RecyclerView;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

/**
 * creater：cyy
 * time：2017/2/8
 * describe：定義{@link android.support.v7.widget.RecyclerView}OnItemClickListener萬能適配器
 */
public abstract class RecyclerAdatper<T> extends RecyclerView.Adapter<RecyclerHolder> {

    private Context mContext;
    private List<T> mList;
    private OnItemClickListener mOnItemClickListener;

    public RecyclerAdatper(Context context) {
        this(context, new ArrayList<T>());
    }

    public RecyclerAdatper(Context context, List<T> list) {
        mContext = context;
        mList = list;
    }

    public Context getContext() {
        return mContext;
    }

    public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
        this.mOnItemClickListener = onItemClickListener;
    }

    @Override
    public RecyclerHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new RecyclerHolder(getLayoutInflater().inflate(getContentView(viewType), parent,
                false));
    }

    @Override
    public int getItemViewType(int position) {
        return super.getItemViewType(position);
    }

    @Override
    public void onBindViewHolder(final RecyclerHolder holder, final int position) {
        onInitView(holder, getItem(position), position);
        if (null != mOnItemClickListener) { // 實現item點擊事件回調
            holder.getView().setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mOnItemClickListener.onItemClick(holder, position);
                }
            });
        }
    }


    @Override
    public int getItemCount() {
        if (null != mList) {
            return mList.size();
        }
        return 0;
    }

    //---------------------------------abstract--------------------------------

    /**
     * item佈局ID
     *
     * @param viewType 類別
     * @return item佈局ID
     */
    public abstract int getContentView(int viewType);

    /**
     * item刷新的回調
     *
     * @param holder   ViewHolder
     * @param object   Item數據對象
     * @param position 刷新的位置
     */
    public abstract void onInitView(RecyclerHolder holder, T object, int position);


    //---------------------------------List--------------------------------
    public List<T> getList() {
        return mList;
    }

    public void setList(List<T> list) {
        this.mList = list;
        notifyDataSetChanged();
    }

    public void clear() {
        this.mList.clear();
        notifyDataSetChanged();
    }

    public void remove(int location) {
        if (location >= 0 && mList.size() > location) {
            this.mList.remove(location);
            notifyDataSetChanged();
        }
    }

    public void add(int location, T object) {
        if (object != null) {
            this.mList.add(location, object);
            notifyDataSetChanged();
        }
    }

    public void addLast(T object) {
        if (object != null) {
            this.mList.add(object);
            notifyDataSetChanged();
        }
    }

    public void addHead(T object) {
        if (object != null) {
            this.mList.add(0, object);
            notifyDataSetChanged();
        }
    }

    public void addAll(List<T> list) {
        if (list != null) {
            this.mList.addAll(list);
            notifyDataSetChanged();
        }
    }

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


    //---------------------------------other--------------------------------
    protected LayoutInflater getLayoutInflater() {
        return (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    /**
     * @param view converView
     * @param id   控件的id
     * @return 返回<T extends View>
     */
    public static <E extends View> E get(View view, int id) {
        SparseArray<View> viewHolder = (SparseArray<View>) view.getTag();
        if (null == viewHolder) {
            viewHolder = new SparseArray<View>();
            view.setTag(viewHolder);
        }
        View childView = viewHolder.get(id);
        if (null == childView) {
            childView = view.findViewById(id);
            viewHolder.put(id, childView);

        }
        return (E) childView;
    }

    protected int getColor(int id) {
        return ContextCompat.getColor(getContext(), id);
    }

    protected String getString(int id) {
        return getContext().getResources().getString(id);
    }

    protected float getDimension(int id) {
        return getContext().getResources().getDimension(id);
    }

    protected Drawable getDrawable(int id) {
        return ContextCompat.getDrawable(getContext(), id);
    }

}

其中RecyclerHolder 是對RecyclerView.ViewHolder一個封裝，讓子類可以快速開發：

package com.recycler.lib;

import android.annotation.SuppressLint;
import android.graphics.Bitmap;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.RecyclerView;
import android.text.TextUtils;
import android.text.util.Linkify;
import android.util.SparseArray;
import android.view.View;
import android.view.animation.AlphaAnimation;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.Checkable;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RatingBar;
import android.widget.TextView;

/**
 * creater：cyy
 * time：2017/2/8
 * describe：
 */
public class RecyclerHolder extends RecyclerView.ViewHolder {

    private View convertView;

    public RecyclerHolder(View itemView) {
        super(itemView);
        convertView = itemView;
    }

    public <T extends View> T getView(int viewId) {
        return retrieveView(viewId);
    }


    protected <T extends View> T retrieveView(int viewId) {
        SparseArray<View> viewHolder = (SparseArray<View>) convertView.getTag();
        if (null == viewHolder) {
            viewHolder = new SparseArray<View>();
            convertView.setTag(viewHolder);
        }
        View childView = viewHolder.get(viewId);
        if (null == childView) {
            childView = convertView.findViewById(viewId);
            viewHolder.put(viewId, childView);

        }
        return (T) childView;
    }

    public RecyclerHolder setText(int viewId, CharSequence value) {
        TextView view = retrieveView(viewId);
        if (TextUtils.isEmpty(value)) {
            view.setText("");
        } else {
            view.setText(value);
        }
        return this;
    }

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

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

    public RecyclerHolder setBackgroundRes(int viewId, int backgroundRes) {
        View view = retrieveView(viewId);
        view.setBackgroundResource(backgroundRes);
        return this;
    }

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

    public RecyclerHolder setTextColorRes(int viewId, int textColorRes) {
        TextView view = retrieveView(viewId);
        view.setTextColor(ContextCompat.getColor(view.getContext(), textColorRes));
        return this;
    }

    public RecyclerHolder setImageDrawable(int viewId, Drawable drawable) {
        ImageView view = retrieveView(viewId);
        view.setImageDrawable(drawable);
        return this;
    }

    public RecyclerHolder setImageBitmap(int viewId, Bitmap bitmap) {
        ImageView view = retrieveView(viewId);
        view.setImageBitmap(bitmap);
        return this;
    }

    @SuppressLint("NewApi")
    public RecyclerHolder setAlpha(int viewId, float value) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            retrieveView(viewId).setAlpha(value);
        } else {
            // Pre-honeycomb hack to set Alpha value
            AlphaAnimation alpha = new AlphaAnimation(value, value);
            alpha.setDuration(0);
            alpha.setFillAfter(true);
            retrieveView(viewId).startAnimation(alpha);
        }
        return this;
    }

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

    public RecyclerHolder setVisible(int viewId, int visibility) {
        View view = retrieveView(viewId);
        view.setVisibility(visibility);
        return this;
    }

    /**
     * Add links into a TextView.
     *
     * @param viewId The id of the TextView to linkify.
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder linkify(int viewId) {
        TextView view = retrieveView(viewId);
        Linkify.addLinks(view, Linkify.ALL);
        return this;
    }

    /**
     * Apply the typeface to the given viewId, and enable subpixel rendering.
     */
    public RecyclerHolder setTypeface(int viewId, Typeface typeface) {
        TextView view = retrieveView(viewId);
        view.setTypeface(typeface);
        view.setPaintFlags(view.getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG);
        return this;
    }

    /**
     * Apply the typeface to all the given viewIds, and enable subpixel
     * rendering.
     */
    public RecyclerHolder setTypeface(Typeface typeface, int... viewIds) {
        for (int viewId : viewIds) {
            TextView view = retrieveView(viewId);
            view.setTypeface(typeface);
            view.setPaintFlags(view.getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG);
        }
        return this;
    }

    /**
     * Sets the progress of a ProgressBar.
     *
     * @param viewId   The view id.
     * @param progress The progress.
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setProgress(int viewId, int progress) {
        ProgressBar view = retrieveView(viewId);
        view.setProgress(progress);
        return this;
    }

    /**
     * Sets the progress and max of a ProgressBar.
     *
     * @param viewId   The view id.
     * @param progress The progress.
     * @param max      The max value of a ProgressBar.
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setProgress(int viewId, int progress, int max) {
        ProgressBar view = retrieveView(viewId);
        view.setMax(max);
        view.setProgress(progress);
        return this;
    }

    /**
     * Sets the range of a ProgressBar to 0...max.
     *
     * @param viewId The view id.
     * @param max    The max value of a ProgressBar.
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setMax(int viewId, int max) {
        ProgressBar view = retrieveView(viewId);
        view.setMax(max);
        return this;
    }

    /**
     * Sets the rating (the number of stars filled) of a RatingBar.
     *
     * @param viewId The view id.
     * @param rating The rating.
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setRating(int viewId, float rating) {
        RatingBar view = retrieveView(viewId);
        view.setRating(rating);
        return this;
    }

    /**
     * Sets the rating (the number of stars filled) and max of a RatingBar.
     *
     * @param viewId The view id.
     * @param rating The rating.
     * @param max    The range of the RatingBar to 0...max.
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setRating(int viewId, float rating, int max) {
        RatingBar view = retrieveView(viewId);
        view.setMax(max);
        view.setRating(rating);
        return this;
    }

    /**
     * Sets the tag of the view.
     *
     * @param viewId The view id.
     * @param tag    The tag;
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setTag(int viewId, Object tag) {
        View view = retrieveView(viewId);
        view.setTag(tag);
        return this;
    }

    /**
     * Sets the tag of the view.
     *
     * @param viewId The view id.
     * @param key    The key of tag;
     * @param tag    The tag;
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setTag(int viewId, int key, Object tag) {
        View view = retrieveView(viewId);
        view.setTag(key, tag);
        return this;
    }

    /**
     * Sets the checked status of a checkable.
     *
     * @param viewId  The view id.
     * @param checked The checked status;
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setChecked(int viewId, boolean checked) {
        Checkable view = (Checkable) retrieveView(viewId);
        view.setChecked(checked);
        return this;
    }

    /**
     * Sets the adapter of a adapter view.
     *
     * @param viewId  The view id.
     * @param adapter The adapter;
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setAdapter(int viewId, Adapter adapter) {
        AdapterView view = retrieveView(viewId);
        view.setAdapter(adapter);
        return this;
    }

    /**
     * Sets the on click listener of the view.
     *
     * @param viewId   The view id.
     * @param listener The on click listener;
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setOnClickListener(int viewId, View.OnClickListener listener) {
        View view = retrieveView(viewId);
        view.setOnClickListener(listener);
        return this;
    }

    public RecyclerHolder setOnCheckedChangeListener(int viewId, CompoundButton.OnCheckedChangeListener listener) {
        CompoundButton view = retrieveView(viewId);
        view.setOnCheckedChangeListener(listener);
        return this;

    }

    /**
     * Sets the on touch listener of the view.
     *
     * @param viewId   The view id.
     * @param listener The on touch listener;
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setOnTouchListener(int viewId, View.OnTouchListener listener) {
        View view = retrieveView(viewId);
        view.setOnTouchListener(listener);
        return this;
    }

    /**
     * Sets the on long click listener of the view.
     *
     * @param viewId   The view id.
     * @param listener The on long click listener;
     * @return The BaseAdapterHelper for chaining.
     */
    public RecyclerHolder setOnLongClickListener(int viewId, View.OnLongClickListener listener) {
        View view = retrieveView(viewId);
        view.setOnLongClickListener(listener);
        return this;
    }

    /**
     * Retrieve the convertView
     */
    public View getView() {
        return convertView;
    }

}