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

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

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

3.MainActiviy

public class MainActivity extends AppCompatActivity {

private SwipeRefreshLayout swipeRefreshLayout;
private RecyclerView recyclerView;
private List<String> 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);

155d7
// 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<RecyclerView.ViewHolder> {

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"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">

<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true">

<android.support.v7.widget.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">

</android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>

</merge>

MainActivity布局文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
>

<include layout="@layout/toolbar" />

<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/SwipeRefreshLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior">

<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical">

</android.support.v7.widget.RecyclerView>
</android.support.v4.widget.SwipeRefreshLayout>
</android.support.design.widget.CoordinatorLayout>

item_base布局文件

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

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

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

<TextView
android:id="@+id/tv_date"

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

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

<TextView
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。" />

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

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

viewFooter布局

<?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="50dp">

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

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

<TextView
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"/>

</RelativeLayout>

</RelativeLayout>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#3F51B5</color>
<color name="colorPrimaryDark">#303F9F</color>
<color name="colorAccent">#FF4081</color>
<color name="blueText">#1485C6</color>
<color name="blueIndexStatus">#67A5EF</color>
<color name="blueStatus">#1680E2</color>

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

<color name="greyBackground">#FFCFCFCF</color>

</resources>