采用SwipeFreshLayout+Recyclerview实现下拉刷新和上拉加载更多以及CoordinatorLayout的引入

       之前都是采用PullToRefresh进行下拉刷新和下拉加载，现在采用谷歌自己的控件SwipeFreshLayout，配合Recyclerview来实现这一效果。使用SwipeRefreshLayout可以实现下拉刷新，前提是布局里需要包裹一个可以滑动的子控件，可以是ListView或者Recyclerview，这里我们采用后者，然后在代码里设置OnRefreshListener设置监听，最后在监听里设置刷新时的数据获取就可以了。CoordinatorLayout主要是为了实现下滑时标题栏隐藏的功能，以后会单独介绍。

SwipeRefreshLayout主要方法介绍

SwipeRefreshLayout只能有一个孩子

• isRefreshing()

  • 判断当前的状态是否是刷新状态。

• setColorSchemeResources(int... colorResIds)

  • 设置下拉进度条的颜色主题，参数为可变参数，并且是资源id，可以设置多种不同的颜色，每转一圈就显示一种颜色。

• setOnRefreshListener(SwipeRefreshLayout.OnRefreshListener listener)

  • 设置监听，需要重写onRefresh()方法，顶部下拉时会调用这个方法，在里面实现请求数据的逻辑，设置下拉进度条消失等等。

• setProgressBackgroundColorSchemeResource(int colorRes)

  • 设置下拉进度条的背景颜色，默认白色。

• setRefreshing(boolean refreshing)

  • 设置刷新状态，true表示正在刷新，false表示取消刷新。

1.添加build.gradle依赖

compile 'com.android.support:recyclerview-v7:25.0.0'
compile 'com.android.support:cardview-v7:25.3.1'
compile 'com.android.support:design:25.3.1'

2.设置app主题

    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar">
    android:name=".MainActivity">
        
            android:name="android.intent.action.MAIN" />

            android:name="android.intent.category.LAUNCHER" />
        
    

3.MainActiviy

public class MainActivity extends AppCompatActivity {

    private SwipeRefreshLayout swipeRefreshLayout;
    private RecyclerView recyclerView;
    private List data = new ArrayList<>();
    public boolean isLoading;
    private RefreshRecyclerAdapter adapter = new RefreshRecyclerAdapter(this, data);
    private Handler handler = new Handler();
    private Toolbar toolbar;
    int topcount = 1;
    int footcount = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.SwipeRefreshLayout);
        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        toolbar = (Toolbar) findViewById(R.id.toolbar);

        setSupportActionBar(toolbar);
        toolbar.setTitle(R.string.notice);
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
        initData();
        initView();


    }

    private void initView() {

        //设置加载进度的颜色变化值
        swipeRefreshLayout.setColorSchemeResources(R.color.blueStatus,R.color.colorAccent, R.color.colorPrimary, R.color.colorPrimaryDark);
        //设置一进入开始刷新
        swipeRefreshLayout.post(new Runnable() {
            @Override
            public void run() {
                swipeRefreshLayout.setRefreshing(true);
            }
        });

        //设置下拉刷新的监听器
        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        addTopNewData();
                    }
                }, 2000);
            }
        });
        final LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setAdapter(adapter);
        //通过recyclerView的onscrolllistener的监听来实现上拉加载更多的功能
        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            //滚动的三种状态包括SCROLL_STATE_IDEL 离开状态 SCROLL_STATE_DRAGGING 手指触摸 SCROLL_STATE_SETLING 加速滑动的时候
            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                Log.d("test", "StateChanged = " + newState);


            }

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
                Log.d("test", "onScrolled");
                 // 获取最后一个可见条目
                int lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
                if (lastVisibleItemPosition + 1 == adapter.getItemCount()) {
                    Log.d("test", "loading executed");
                    //获取刷新状态
                    boolean isRefreshing = swipeRefreshLayout.isRefreshing();
                    if (isRefreshing) {
                        adapter.notifyItemRemoved(adapter.getItemCount());
                        return;
                    }
                    if (!isLoading) {
                        isLoading = true;
                        handler.postDelayed(new Runnable() {
                            @Override
                            public void run() {
                                addNewData();
                                Log.d("test", "load more completed");
                                isLoading = false;
                            }
                        }, 1000);
                    }
                }
            }
        });

        //添加点击事件
        adapter.setOnItemClickListener(new RefreshRecyclerAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(View view, int position) {
                Log.d("test", "item position = " + position);
            }

            @Override
            public void onItemLongClick(View view, int position) {

            }
        });
    }

    /**
     * 下拉加载更多
     */
    private void addTopNewData() {

        for (int i = topcount; i < topcount +6; i++) {
            data.add(0,"下拉加载的第"+i+"条数据");

        }
        topcount += 6;
        adapter.notifyDataSetChanged();
        swipeRefreshLayout.setRefreshing(false);
    }


    public void initData() {
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                getData();
            }
        }, 1500);

    }

    /**
     * 获取测试数据
     */
    private void getData() {
        for (int i =0; i <10; i++) {
            data.add(i,"第"+i+"条数据");
        }
        adapter.notifyDataSetChanged();
        swipeRefreshLayout.setRefreshing(false);
       // adapter.notifyItemRemoved(adapter.getItemCount());
    }

    /**
     * 上拉加载更多
     */
    public void addNewData() {

        for (int i = footcount; i < footcount+ 6; i++) {
            data.add(data.size(),"上拉加载的第"+i+"条数据");
        }
        footcount += 6;
        adapter.notifyDataSetChanged();
        swipeRefreshLayout.setRefreshing(false);
        //adapter.notifyItemRemoved(adapter.getItemCount());
    }

}

4.RefreshRecyclerAdapter

public class RefreshRecyclerAdapter extends RecyclerView.Adapter {

    private static final int TYPE_ITEM = 0;
    private static final int TYPE_FOOTER = 1;//上拉加载更多布局
    private Context context;
    private List data;

    public RefreshRecyclerAdapter(Context context, List data) {
        this.context = context;
        this.data = data;
    }

    public interface OnItemClickListener {
        void onItemClick(View view, int position);

        void onItemLongClick(View view, int position);
    }

    private OnItemClickListener onItemClickListener;

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

    @Override
    public int getItemCount() {
        return data.size() == 0 ? 0 : data.size() + 1;
    }

    @Override
    public int getItemViewType(int position) {
        if (position + 1 == getItemCount()) {
            return TYPE_FOOTER;
        } else {
            return TYPE_ITEM;
        }
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (viewType == TYPE_ITEM) {
            View view = LayoutInflater.from(context).inflate(R.layout.item_base, parent,
                    false);
            return new ItemViewHolder(view);
        } else if (viewType == TYPE_FOOTER) {
            View view = LayoutInflater.from(context).inflate(R.layout.view_footer, parent,
                    false);
            return new FootViewHolder(view);
        }
        return null;
    }

    @Override
    public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
        if (holder instanceof ItemViewHolder) {
            ((ItemViewHolder) holder).tv.setText((CharSequence) data.get(position));
            if (onItemClickListener != null) {
                holder.itemView.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        int position = holder.getLayoutPosition();
                        onItemClickListener.onItemClick(holder.itemView, position);
                    }
                });

                holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
                    @Override
                    public boolean onLongClick(View v) {
                        int position = holder.getLayoutPosition();
                        onItemClickListener.onItemLongClick(holder.itemView, position);
                        return false;
                    }
                });
            }
        }
    }


    static class ItemViewHolder extends RecyclerView.ViewHolder {

        TextView tv;

        public ItemViewHolder(View view) {
            super(view);
            tv = (TextView) view.findViewById(R.id.tv_date);
        }
    }

    static class FootViewHolder extends RecyclerView.ViewHolder {

        public FootViewHolder(View view) {
            super(view);
        }
    }
}

5.布局文件

ToolBar

xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

            android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fitsSystemWindows="true">

        Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/blueStatus"
            android:minHeight="?attr/actionBarSize"
            app:layout_scrollFlags="scroll|enterAlways"
            app:navigationIcon="?attr/homeAsUpIndicator"
            app:theme="@style/Theme.AppCompat.NoActionBar">

        Toolbar>
    

MainActivity布局文件

xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    android:orientation="vertical"
    >

    layout="@layout/toolbar" />

            android:id="@+id/SwipeRefreshLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

                    android:id="@+id/recyclerView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scrollbars="vertical">

        
    

item_base布局文件

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

xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="10dp"
    android:layout_marginRight="10dp"

    android:layout_marginTop="6dp"
    android:orientation="vertical"
    app:cardBackgroundColor="@color/line"
    app:cardPreventCornerOverlap="true"
    app:cardUseCompatPadding="true"
    app:contentPadding="6dp">

            android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

                    android:id="@+id/tv_date"

            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="2015-12-11 12:00" />

                    android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            app:cardBackgroundColor="@color/white"
            app:cardPreventCornerOverlap="true"
            app:cardUseCompatPadding="true"
            app:contentPadding="10dp">

                            android:id="@+id/tv_title"

                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:ellipsize="end"
                android:maxLines="2"
                android:text="swipefreshlayout测试使用通过。。通过。。通过。" />

        
    

viewFooter布局

xml version="1.0" encoding="utf-8"?>
xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="50dp">

            android:layout_width="match_parent"
        android:layout_height="50dp">


                    android:id="@+id/load_progress"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:layout_centerVertical="true"
            android:layout_marginLeft="30dp"/>

                    android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:text="正在努力加载中..."
            android:textColor="@android:color/holo_red_dark"
            android:textSize="15sp"/>

    

colors.xml

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

    name="colorPrimary">#3F51B5
    name="colorPrimaryDark">#303F9F
    name="colorAccent">#FF4081
    name="blueText">#1485C6
    name="blueIndexStatus">#67A5EF
    name="blueStatus">#1680E2

    name="white">#FFFFFFFF
    name="dark">#424242
    name="red">#FFD4212A
    name="grey">#8C8C8C
    name="line">#EEEEEE
    name="background">#F9F9FA

    name="greyBackground">#FFCFCFCF