Android RecycleView + CardView 控件简析

今天使用了V7包加入的RecycleView 和 CardView，写篇简析。

先上效果图：

原理图：

这是RecycleView的工作原理：

1.LayoutManager用来处理RecycleView的“列表”样式，Support包默认包含了：LinearLayoutManager  横向或纵向的滚动列表、

GridLayoutManager  网格列表、StaggeredGridLayoutManager  交错的网格列表。

2.Adapter负责处理RecycleView的数据和样式

3.在传统的ListView中有一种常见的写法是使用ViewHolder来缓存数据集，在新版的RecycleView内置了ViewHolder这一模块，所以在Adapter内部新建内部类ViewHolder。

4.RecycleView 和listView的一个区别就是本身不处理点击事件，点击事件应该绑在ViewHolder里面，可以直接写也可以通过接口绑在Adapter里面来实现。

首先添加数据集：

package com.lfk.drawapictiure.Info;

/**

 * Created by liufengkai on 15/9/13.

 */

public class MenuInfo {

    private String paint_name;

    private String paint_time;

    private String paint_root;

    private String paint_img_root;

    public MenuInfo(String paint_name, String paint_time,

                    String paint_root, String paint_img_root) {

        this.paint_name = paint_name;

        this.paint_time = paint_time;

        this.paint_root = paint_root;

        this.paint_img_root = paint_img_root;

    }

    public String getPaint_name() {

        return paint_name;

    }

    public String getPaint_time() {

        return paint_time;

    }

    public String getPaint_root() {

        return paint_root;

    }

    public String getPaint_img_root() {

        return paint_img_root;

    }

}

实现继承自RecycleView的Adapter中间要包裹自己实现的ViewHolder，onCreateviewHolder函数和onBindViewHolder实现了ListView里面getView的工作，分别为找到控件和控件赋值，

实现点击的接口，设置接口并且绑在ViewHolder的itemView里面即根视图中

public class MainLayoutAdapter extends RecyclerView.Adapter<MainLayoutAdapter.MainViewHolder> {

    private LayoutInflater inflater;

    private ArrayList<MenuInfo> userList;

    private Context context;

    private MainItemClickListener itemClickListener;

    public MainLayoutAdapter(ArrayList<MenuInfo> userList, Context context) {

        this.userList = userList;

        this.context = context;

        this.inflater = LayoutInflater.from(context);

    }

    public void setItemClickListener(MainItemClickListener itemClickListener) {

        this.itemClickListener = itemClickListener;

    }

　　//onCreateviewHolder函数和onBindViewHolder实现了ListView里面getView的工作，分别为找到控件和控件赋值

    @Override

    public MainLayoutAdapter.MainViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View wrapper = inflater.inflate(R.layout.draw_item, parent, false);

        return new MainViewHolder(

                wrapper,

                (TextView)wrapper.findViewById(R.id.paint_name),

                (TextView)wrapper.findViewById(R.id.paint_time),

                (TextView)wrapper.findViewById(R.id.paint_root),

                (ImageView)wrapper.findViewById(R.id.paint_img));

    }

    @Override

    public void onBindViewHolder(MainViewHolder holder, int position) {

        MenuInfo menuInfo = userList.get(position);

        holder.paint_img.setImageURI(Uri.parse(menuInfo.getPaint_img_root()));

        holder.paint_name.setText(menuInfo.getPaint_name());

        holder.paint_time.setText(menuInfo.getPaint_time());

        holder.paint_root.setText(menuInfo.getPaint_root());

    }

    @Override

    public int getItemCount() {

        return userList.size();

    }

    public class MainViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnLongClickListener{

        private TextView paint_name;

        private TextView paint_time;

        private TextView paint_root;

        private ImageView paint_img;

        public MainViewHolder(View itemView, TextView paint_name,

                          TextView paint_time, TextView paint_root,

                          ImageView paint_img) {

            super(itemView);

            itemView.setOnClickListener(this);

            this.paint_name = paint_name;

            this.paint_time = paint_time;

            this.paint_root = paint_root;

            this.paint_img = paint_img;

        }

        @Override

        public void onClick(View view) {

            MenuInfo menuInfo = userList.get(getAdapterPosition());

            itemClickListener.onItemClick(view,menuInfo.getPaint_name(),menuInfo.getPaint_root());

        }

        @Override

        public boolean onLongClick(View view) {

            return false;

        }

    }

}

Activity中的使用：

package com.lfk.drawapictiure.Fragment;

import android.content.Intent;

import android.net.Uri;

import android.os.Bundle;

import android.os.Environment;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import com.lfk.drawapictiure.Adapter.MainLayoutAdapter;

import com.lfk.drawapictiure.Info.MenuInfo;

import com.lfk.drawapictiure.InterFace.MainItemClickListener;

import com.lfk.drawapictiure.MainActivity;

import com.lfk.drawapictiure.R;

import java.util.ArrayList;

public class PaintFragment extends android.support.v4.app.Fragment {

    private RecyclerView mRecyclerView;

    private MainLayoutAdapter mAdapter;

    private RecyclerView.LayoutManager mLayoutManager;

    private String path = Environment.getExternalStorageDirectory().getPath() + "/DrawAPicture";

    public static PaintFragment newInstance() {

        return new PaintFragment();

    }

    public PaintFragment() {

        // Required empty public constructor

    }

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

    }

    @Override

    public View onCreateView(LayoutInflater inflater, ViewGroup container,

                             Bundle savedInstanceState) {

        View wrapper = inflater.inflate(R.layout.fragment_paint, container, false);

        mRecyclerView = (RecyclerView)wrapper.findViewById(R.id.paint_recycle_view);

        mLayoutManager = new LinearLayoutManager(getActivity());

        mRecyclerView.setLayoutManager(mLayoutManager); //绑上列表管理器

        ArrayList<MenuInfo> arrayList = new ArrayList<>();

        arrayList.add(new MenuInfo("刘丰恺","09-13 05:28",path+"/"+"12138.lfk",path+"/"+"6826.jpg"));

        arrayList.add(new MenuInfo("刘丰恺","09-13 05:28",path+"/"+"12138.lfk",path+"/"+"6826.jpg"));

        arrayList.add(new MenuInfo("刘丰恺","09-13 05:28",path+"/"+"12138.lfk",path+"/"+"6826.jpg"));

        arrayList.add(new MenuInfo("刘丰恺","09-13 05:28",path+"/"+"12138.lfk",path+"/"+"6826.jpg"));

        mAdapter = new MainLayoutAdapter(arrayList, getActivity());

　　　　　　// 设置点击事件

        mAdapter.setItemClickListener(new MainItemClickListener() {

            @Override

            public void onItemClick(View view, String name, String path) {

                Intent intent = new Intent(getActivity(), MainActivity.class);

                intent.setData(Uri.parse(path));

                startActivity(intent);

            }

        });

　　　　　　//绑定数据集

        mRecyclerView.setAdapter(mAdapter);

        return wrapper;

    }

}

其中的子布局使用了CardView:

<?xml version="1.0" encoding="utf-8"?>

<android.support.v7.widget.CardView

    xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:card_view="http://schemas.android.com/apk/res-auto"

    android:background="@drawable/list_item_selector"

    android:layout_width="match_parent"

    android:layout_height="wrap_content"

    card_view:cardCornerRadius="4dp"

　　　　card_view:

    android:layout_margin="@dimen/card_margin">

    <RelativeLayout

        android:layout_marginTop="16dp"

        android:layout_marginLeft="16dp"

        android:layout_marginRight="16dp"

        android:layout_marginBottom="16dp"

        android:layout_width="match_parent"

        android:layout_height="wrap_content">

        <ImageView

            android:maxHeight="100dp"

            android:layout_marginTop="8dp"

            android:layout_below="@+id/line_view"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:id="@+id/paint_img"

            android:src="@mipmap/ic_launcher" />

        <TextView

            android:id="@+id/paint_name"

            android:textColor="#000"

            android:textSize="18sp"

            android:text="项目名"

            android:layout_alignParentRight="true"

            android:singleLine="true"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content" />

        <TextView

            android:id="@+id/paint_time"

            android:text="项目时间"

            android:textColor="@color/black"

            android:textSize="18sp"

            android:singleLine="true"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content" />

        <View

            android:id="@+id/line_view"

            android:background="@color/gray"

            android:layout_below="@+id/paint_time"

            android:layout_width="match_parent"

            android:layout_height="1dp"/>

        <TextView

            android:id="@+id/paint_root"

            android:visibility="invisible"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content" />

    </RelativeLayout>

</android.support.v7.widget.CardView>

我设置的东西只有：

card_view:cardCornerRadius="4dp"  //设定圆角半径

card_view:cardElevation="8dp"//设定阴影