说实话现在大部分人都不在用ListView了，不过说实话如果仅仅是普通的列表其实用哪个都无所谓的。 可能有人会说有好多第三方的下拉刷新上拉加载的框架，但是我觉得吧，有些东西自己能实现的就还是用自己写的好。 不罗嗦了，直接上代码，注释都已写好
代码语言：javascript复制/**
* 继承自SwipeRefreshLayout,从而实现滑动到底部时上拉加载更多的功能.
*/
public class RefreshLayout extends SwipeRefreshLayout implements
OnScrollListener {
/**
* 滑动到最下面时的上拉操作
*/
private int mTouchSlop;
/**
* listview实例
*/
private ListView mListView;
/**
* 上拉监听器, 到了最底部的上拉加载操作
*/
private OnLoadListener mOnLoadListener;
/**
* ListView的加载中footer
*/
private View mListViewFooter;
/**
* 按下时的y坐标
*/
private int mYDown;
/**
* 抬起时的y坐标, 与mYDown一起用于滑动到底部时判断是上拉还是下拉
*/
private int mLastY;
/**
* 是否在加载中 ( 上拉加载更多 )
*/
private boolean isLoading = false;
/**
* @param context
*/
public RefreshLayout(Context context) {
this(context, null);
}
@SuppressLint("InflateParams")
public RefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
mListViewFooter = LayoutInflater.from(context).inflate(
R.layout.listview_footer, null, false);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right,
int bottom) {
super.onLayout(changed, left, top, right, bottom);
// 初始化ListView对象
if (mListView == null) {
getListView();
}
}
/**
* 获取ListView对象
*/
private void getListView() {
int childs = getChildCount();
if (childs > 0) {
View childView = getChildAt(0);
if (childView instanceof ListView) {
mListView = (ListView) childView;
// 设置滚动监听器给ListView, 使得滚动的情况下也可以自动加载
mListView.setOnScrollListener(this);
Log.d(VIEW_LOG_TAG, "### 找到listview");
}
}
}
/*
* (non-Javadoc)
*
* @see android.view.ViewGroup#dispatchTouchEvent(android.view.MotionEvent)
*/
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
final int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
// 按下
mYDown = (int) event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
// 移动
mLastY = (int) event.getRawY();
break;
case MotionEvent.ACTION_UP:
// 抬起
if (canLoad()) {
loadData();
}
break;
default:
break;
}
return super.dispatchTouchEvent(event);
}
/**
* 是否可以加载更多, 条件是到了最底部, listview不在加载中, 且为上拉操作.
*
* @return
*/
private boolean canLoad() {
return isBottom() && !isLoading && isPullUp();
}
/**
* 判断是否到了最底部
*/
private boolean isBottom() {
if (mListView != null && mListView.getAdapter() != null) {
return mListView.getLastVisiblePosition() == (mListView
.getAdapter().getCount() - 1);
}
return false;
}
/**
* 是否是上拉操作
*
* @return
*/
private boolean isPullUp() {
return (mYDown - mLastY) >= mTouchSlop;
}
/**
* 如果到了最底部,而且是上拉操作.那么执行onLoad方法
*/
private void loadData() {
if (mOnLoadListener != null) {
// 设置状态
setLoading(true);
//
mOnLoadListener.onLoad();
}
}
/**
* @param loading
*/
public void setLoading(boolean loading) {
isLoading = loading;
if (isLoading) {
mListView.addFooterView(mListViewFooter);
} else {
mListView.removeFooterView(mListViewFooter);
mYDown = 0;
mLastY = 0;
}
}
/**
* @param loadListener
*/
public void setOnLoadListener(OnLoadListener loadListener) {
mOnLoadListener = loadListener;
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// 滚动时到了最底部也可以加载更多
if (canLoad()) {
loadData();
}
}
/**
* 设置刷新
*/
public static void setRefreshing(SwipeRefreshLayout refreshLayout,
boolean refreshing, boolean notify) {
Class<? extends SwipeRefreshLayout> refreshLayoutClass = refreshLayout
.getClass();
if (refreshLayoutClass != null) {
try {
Method setRefreshing = refreshLayoutClass.getDeclaredMethod(
"setRefreshing", boolean.class, boolean.class);
setRefreshing.setAccessible(true);
setRefreshing.invoke(refreshLayout, refreshing, notify);
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
/**
* 加载更多的监听器
*/
public static interface OnLoadListener {
public void onLoad();
}
}下面写一下如何使用
- 在布局中使用自定义的RefreshLayout包裹ListView
<RefreshLayout
android:id="@ id/refreshLayout"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="8">
<ListView
android:id="@ id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="@null" />
</RefreshLayout>- 在Activity中调用refresh()方法，做RefreshLayout的监听和颜色设置
private void refresh() {
refreshLayout.setColorSchemeResources(R.color.colorPrimary, R.color.colorAccent, R.color.colorAccent, R.color.colorPrimaryDark);
//下拉刷新
refreshLayout.setOnRefreshListener(this);
//上拉加载
refreshLayout.setOnLoadListener(this);
}- 最后在实现的刷新和上拉监听中加refreshLayout.setLoading(false);使下拉和上拉的加载框消失
- 下拉刷新加在onRefresh方法最后即可
@Override
public void onRefresh() {
//加在最后
refreshLayout.setRefreshing(false);
}- 上拉监听需加在响应方法中即可
@Override
public void onLoad() {
page = page;
yNProgressDialog.show();
NetTool.getInstance().rxPostNet().subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<>() {
@Override
public void accept(@NonNull Bean eBean) throws Exception {
NProgressDialog.dismiss();
if (eBean.getSuccess().equals("1")) {
refreshLayout.setLoading(false);
eAdapter.addData(eBean);
} else {
refreshLayout.setLoading(false);
refreshLayout.setOnLoadListener(null);
Toast.makeText(getApplicationContext().getApplicationContext(), eBean.getMsg().toString(), Toast.LENGTH_SHORT).show();
}
}
}, new Consumer<Throwable>() {
@Override
public void accept(@NonNull Throwable throwable) throws Exception {
refreshLayout.setLoading(false);
NProgressDialog.dismiss();
Toast.makeText(getApplicationContext().getApplicationContext(), "连接异常", Toast.LENGTH_SHORT).show();
}
});
}
