RecyclerView 的用法探秘 （基础篇）

RecyclerView 的用法探秘 （基础篇）

ListView 一统天下的时代，是我目前用的最多一个控件；从事Android开发几年多来，很多时候都是围绕着这个东东码代码；现在，终于迎来了解放双手的时候。RecyclerView 的时代正式来临；
先简单的说一下我在使用这个控件的基本思路和步骤：
1. 首先构建数据模型：即model:——javeBean;
2. 新建布局文件：Item（每个列表项目中都有哪些控件），为适配器做准备；
3. 新建Activity布局，即包含RecyclerView 的布局；
4. 核心工作，适配器的编写；很多时候都是在编写适配器；
话不多说，直接上代码：数据模型的代码此处略过，从布局文件开始

item_envent.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="44dp"
                android:minHeight="44dp"
                android:background="@drawable/bar_case_bg"
    >
    <ImageView
        android:id="@+id/iv_not_onclick"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:layout_marginRight="18dp"
        />

    <TextView
        android:id="@+id/event_title_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/bg_black"
        android:textSize="@dimen/content_fonts_size_16"
        android:text="打开开关"
        android:paddingLeft="13.0dip"
        android:layout_centerVertical="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"/>
</RelativeLayout>

Activity 布局中包含RecyelerView
activity_condition.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/bg_content"
    >
    <android.support.v7.widget.RecyclerView
        android:id="@+id/device_condition_rcy"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        />
    <TextView
        android:id="@+id/tips_tx"
        style="@style/content_text"
        android:layout_centerInParent="true"
        android:visibility="gone"/>

</RelativeLayout>

下面就是通用适配器：一次编写，处处运行；这个通用适配器用泛型的方式进行具体业务数据的绑定；它继承了RecyclerView.Adapter;

package com.cloudring.smarthome.adapter;

import android.content.Context;
import android.support.annotation.Nullable;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

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

/**
 * Created by qingwufeiyang
 * <p>
 * Description:自定义通用的RecyclerView Adapter
 */
public abstract class CommonAdapter<T> extends RecyclerView.Adapter<CommonViewHolder> {
    protected Context mContext;
    protected List<T> mDatas = new ArrayList<>();
    protected OnItemClickListener<T> mOnItemClickListener;
    private int mItemViewID;


    public CommonAdapter(Context context, List<T> datas, int itemView) {
        this.mContext = context;
        this.mDatas = datas;
        this.mItemViewID = itemView;
    }

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

    @Override
    public CommonViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        CommonViewHolder holder = CommonViewHolder.createViewHolder(mContext, parent, mItemViewID);
        setListener(parent, holder, viewType);
        return holder;
    }

    public abstract void convert(CommonViewHolder holder, T t);

    protected boolean isEnabled(int viewType) {
        return true;
    }


    protected void setListener(final ViewGroup parent, final CommonViewHolder viewHolder, int viewType) {
        if (!isEnabled(viewType)) return;
        viewHolder.getConvertView().setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mOnItemClickListener != null) {
                    int position = viewHolder.getLayoutPosition();
                    T t = null;
                    if (position >= 0 && position < mDatas.size()) {
                        t = mDatas.get(position);
                    }
                    mOnItemClickListener.onItemClick(v, viewHolder, t, position);
                }
            }
        });

        viewHolder.getConvertView().setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                if (mOnItemClickListener != null) {
                    int position = viewHolder.getLayoutPosition();
                    T t = null;
                    if (position >= 0 && position < mDatas.size()) {
                        t = mDatas.get(position);
                    }
                    return mOnItemClickListener.onItemLongClick(v, viewHolder, t, position);
                }
                return false;
            }
        });
    }

    @Override
    public void onBindViewHolder(CommonViewHolder holder, int position) {
        convert(holder, mDatas.get(position));
    }

    @Override
    public int getItemCount() {
        int itemCount = mDatas.size();
        return itemCount;
    }

    public List<T> getDatas() {
        return mDatas;
    }

    public interface OnItemClickListener<T> {
        void onItemClick(View view, RecyclerView.ViewHolder holder, @Nullable T o, int position);

        boolean onItemLongClick(View view, RecyclerView.ViewHolder holder, @Nullable T o, int position);
    }

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

接下来看看CommonViewHolder 的实现逻辑：

package com.cloudring.smarthome.adapter;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.v7.widget.RecyclerView;
import android.text.util.Linkify;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.widget.CheckBox;
import android.widget.Checkable;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RatingBar;
import android.widget.TextView;

/**
 * Created by qingwufeiyang on Mon
 *
 * 自定义通用的RecyclerView ViewHolder
 */
public class CommonViewHolder extends RecyclerView.ViewHolder {
    private SparseArray<View> mViews;
    private View mConvertView;
    private Context mContext;

    public CommonViewHolder(Context context, View itemView) {
        super(itemView);
        mContext = context;
        mConvertView = itemView;
        mViews = new SparseArray<View>();
    }

    public static CommonViewHolder createViewHolder(Context context, View itemView) {
        CommonViewHolder holder = new CommonViewHolder(context, itemView);
        return holder;
    }

    public static CommonViewHolder createViewHolder(Context context,
                                              ViewGroup parent, int layoutId) {
        View itemView = LayoutInflater.from(context).inflate(layoutId, parent,
                false);
        CommonViewHolder holder = new CommonViewHolder(context, itemView);
        return holder;
    }

    /**
     * 通过viewId获取控件
     *
     * @param viewId
     * @return
     */
    public <T extends View> T getView(int viewId) {
        View view = mViews.get(viewId);
        if (view == null) {
            view = mConvertView.findViewById(viewId);
            mViews.put(viewId, view);
        }
        return (T) view;
    }

    public View getConvertView() {
        return mConvertView;
    }


    /****以下为辅助方法*****/

    /**
     * 设置TextView的值
     *
     * @param viewId
     * @param text
     * @return
     */
    public CommonViewHolder setText(int viewId, String text) {
        TextView tv = getView(viewId);
        tv.setText(text);
        return this;
    }

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

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

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

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

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

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

    public CommonViewHolder setTextColorRes(int viewId, int textColorRes) {
        TextView view = getView(viewId);
        view.setTextColor(mContext.getResources().getColor(textColorRes));
        return this;
    }

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

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

    public CommonViewHolder linkify(int viewId) {
        TextView view = getView(viewId);
        Linkify.addLinks(view, Linkify.ALL);
        return this;
    }

    public CommonViewHolder setTypeface(Typeface typeface, int... viewIds) {
        for (int viewId : viewIds) {
            TextView view = getView(viewId);
            view.setTypeface(typeface);
            view.setPaintFlags(view.getPaintFlags() | Paint.SUBPIXEL_TEXT_FLAG);
        }
        return this;
    }

    public CommonViewHolder setProgress(int viewId, int progress) {
        ProgressBar view = getView(viewId);
        view.setProgress(progress);
        return this;
    }

    public CommonViewHolder setProgress(int viewId, int progress, int max) {
        ProgressBar view = getView(viewId);
        view.setMax(max);
        view.setProgress(progress);
        return this;
    }

    public CommonViewHolder setMax(int viewId, int max) {
        ProgressBar view = getView(viewId);
        view.setMax(max);
        return this;
    }

    public CommonViewHolder setRating(int viewId, float rating) {
        RatingBar view = getView(viewId);
        view.setRating(rating);
        return this;
    }

    public CommonViewHolder setRating(int viewId, float rating, int max) {
        RatingBar view = getView(viewId);
        view.setMax(max);
        view.setRating(rating);
        return this;
    }

    public CommonViewHolder setTag(int viewId, Object tag) {
        View view = getView(viewId);
        view.setTag(tag);
        return this;
    }

    public CommonViewHolder setTag(int viewId, int key, Object tag) {
        View view = getView(viewId);
        view.setTag(key, tag);
        return this;
    }

    public CommonViewHolder setChecked(int viewId, boolean checked) {
        Checkable view = (Checkable) getView(viewId);
        view.setChecked(checked);
        return this;
    }

    /**
     * 关于事件的
     */
    public CommonViewHolder setOnClickListener(int viewId,
                                         View.OnClickListener listener) {
        View view = getView(viewId);
        view.setOnClickListener(listener);
        return this;
    }

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

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

    public CommonViewHolder setOnCheckedChangeListener(int viewId,
                                     CompoundButton.OnCheckedChangeListener listener){
        CheckBox view  = getView(viewId);
        view.setOnCheckedChangeListener(listener);
        return this;
    }
}

好了，我们的准备工作做完了，那么接下来就要看看如何在自己的Activity 中使用
详细的代码就不重复了。只写一下大概的实现；
for example:

//先实例化一个CommonAdapter<T Class>--注意此处
   private CommonAdapter<DeviceEventInfo.EventList> commonAdapter;
   private void initView(){
   // 初始化常用组件
   //实例化适配器，这块需要说明一下，原莱的listView BaseAdapter 是通过构造
   //函数的方式传值的；而现在的CommonAdapter是通过泛型<>进行传数据封装和适配的；
   //R.layout.item_envent:item 的布局；
   //eventList: 数据集合 传入；
     commonAdapter = new CommonAdapter<DeviceEventInfo.EventList>(context, eventList, R.layout.item_envent) {
                @Override
                public void convert(CommonViewHolder holder, DeviceEventInfo.EventList eventList) {
                    holder.setText(R.id.event_title_tv, eventList.event_name);
                }
            };
            // 事件回掉监听；
            commonAdapter.setOnItemClickListener(new CommonAdapter.OnItemClickListener<DeviceEventInfo.EventList>() {
                @Override
                public void onItemClick(View view, RecyclerView.ViewHolder holder, DeviceEventInfo.EventList eventBean, int position) {
                    if (eventBean.trigger_parameter != null && eventBean.trigger_parameter.size() > 0) {
                        triggerParameterList = eventBean.trigger_parameter;
                        Intent intent = new Intent(context, TriggerParameterActivity.class);
                        intent.putExtra("triggerParameterList", (Serializable) eventBean);
                        if (deviceBean != null) intent.putExtra("deviceBean", (Serializable) deviceBean);
                        DeviceConditionActivity.this.startActivity(intent);
                        finish();
                    } else {
                        Map<String, String> data = new HashMap<>();
                        data.put("event_id", eventBean.event_id);
                        data.put("eventName", eventBean.event_name);
                        data.put("step", "1");
                        data.put("eventType", "event");
                        data.put("trigger_type", eventBean.trigger_type);
                        data.put("device_type_id",deviceTypeId);
                        data.put("device_id",deviceBean.getDeviceId());
                        //选择了一个事件
                        SharedUtils.putInt("superApp", DeviceConditionActivity.this, "isSeletedEvent", 1);
                        EventBus.getDefault().post(new BaseEventMessage<Map<String, String>>("get_event_name", data));
                        finish();
                    }
                }

                @Override
                public boolean onItemLongClick(View view, RecyclerView.ViewHolder holder, DeviceEventInfo.EventList eventBean, int position) {
                    return false;
                }
            });
            rcyTrigger.setAdapter(commonAdapter);
   }

最后一点就是：根据具体的业务规则，让itme显示不同的数据或者图片字段，或者是字体颜色因不同的业务规则；这就需要对具体的ViewHolder 进行判断；