Android实现RecyclerView下拉刷新效果
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2022-04-13 22:49:59
本文为大家分享了android实现recyclerview下拉刷新效果的具体代码，供大家参考，具体内容如下
思路
realpullrefreshview继承了一...
本文为大家分享了android实现recyclerview下拉刷新效果的具体代码，供大家参考，具体内容如下
思路
- realpullrefreshview继承了一个linearlayout
- 里面放置了一个刷新头布局，将其margin_top设置为负的刷新头的高度的
- 再添加一个recyclerview
- 触摸事件分发机制，当在特定条件下让realpullrefreshview拦截触摸事件，否则的话，不拦截，让recyclerview自己去处理触摸事件
- 在手指下拉时，定义好不同的状态state,在不同状态下，处理不同的显示，这里讲不同状态下的刷新头如何显示，抽象为一个接口，用户可以实现这个接口，自定义刷新头的布局和动画
- 加载更多的功能是利用recyclerview的多type布局实现的
- 难点在于触摸事件的拦截，和认真处理各种滑动的问题
使用
xml
<com.example.apple.quickdemo.realview.view.realpullrefreshview
android:id="@+id/real_pull_refresh_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:refresh_header_view="@layout/headerview"/>
这是headerview
<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="#ff0"
android:orientation="horizontal"
android:gravity="center">
<textview
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:background="@color/coloraccent"
android:visibility="visible"
android:id="@+id/tv"
android:gravity="center"
android:text="下拉刷新"
android:textsize="21sp"/>
<imageview
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@mipmap/ic_launcher"
android:id="@+id/iv"
/>
</linearlayout>
代码
mrealpullrefreshview.setlayoutmanager(mlayoutmanager);
mrealpullrefreshview.setadapter(mmyadapte);
//用户可以自定义自己的刷新头布局和动画
//mrealpullrefreshview.setonpullshowviewlistener(new gifonpullshowviewlisterner(mrealpullrefreshview));
mrealpullrefreshview.setonpulllistener(new realpullrefreshview.onpulllistener() {
@override
public void onrefresh() {
mhandler.postdelayed(new runnable() {
@override
public void run() {
mbodies.add(0, new body("新数据"+i++,100));
mrealpullrefreshview.refreshfinish();
}
}, 3000);
}
@override
public void onloadmore() {
final list<body> more=new arraylist<body>();
mhandler.postdelayed(new runnable() {
@override
public void run() {
for (int i = 0; i < 3; i++) {
more.add(new body("more+++"+i,100));
}
mbodies.addall(more);
mrealpullrefreshview.loadmrefinish();
}
}, 1500);
}
});
自定义刷新头布局和动画
package com.example.apple.quickdemo.realview.show;
import android.animation.objectanimator;
import android.animation.valueanimator;
import android.util.log;
import android.view.view;
import android.widget.imageview;
import android.widget.textview;
import com.example.apple.quickdemo.r;
import com.example.apple.quickdemo.realview.view.realpullrefreshview;
/**
* created by apple on 2017/7/9.
*/
public class implonpullshowviewlistener implements realpullrefreshview.onpullshowviewlistener {
private textview mtv;
private imageview miv;
private objectanimator mani;
view mheaderview;
public implonpullshowviewlistener(realpullrefreshview realpullrefreshview) {
mheaderview = realpullrefreshview.getrefreshheaderview();
mtv = (textview) mheaderview.findviewbyid(r.id.tv);
miv = (imageview) mheaderview.findviewbyid(r.id.iv);
mani = objectanimator.offloat(miv, "rotation", -15, 15).setduration(300);
mani.setrepeatcount(valueanimator.infinite);
mani.setrepeatmode(valueanimator.reverse);
}
@override
public void onpulldownrefreshstate(int scrolly, int headviewheight,int deltay) {
mtv.settext("下拉刷新");
float f = -((float) scrolly / (float) headviewheight);
log.e("tag", f+ "");
log.e("tag", -scrolly + "scrolly");
miv.setscalex(f);
miv.setscaley(f);
}
@override
public void onreleaserefreshstate(int scrolly, int deltay) {
mtv.settext("松手刷新");
}
@override
public void onrefreshingstate() {
mtv.settext("正在刷新");
miv.setscalex(1.0f);
miv.setscaley(1.0f);
mani.start();
}
@override
public void ondefaultstate() {
if (mani.isrunning()){
mani.end();
miv.setrotation(0);
}
}
}
源码
package com.example.apple.quickdemo.realview.view;
import android.content.context;
import android.content.res.typedarray;
import android.support.annotation.nullable;
import android.support.v7.widget.gridlayoutmanager;
import android.support.v7.widget.linearlayoutmanager;
import android.support.v7.widget.recyclerview;
import android.support.v7.widget.staggeredgridlayoutmanager;
import android.util.attributeset;
import android.util.log;
import android.view.layoutinflater;
import android.view.motionevent;
import android.view.velocitytracker;
import android.view.view;
import android.view.viewgroup;
import android.widget.linearlayout;
import android.widget.scroller;
import android.widget.toast;
import com.example.apple.quickdemo.r;
import com.example.apple.quickdemo.realview.show.implonpullshowviewlistener;
import static android.content.contentvalues.tag;
/**
* created by apple on 2017/7/7.
* 下拉刷新
*/
public class realpullrefreshview extends linearlayout {
private int mtouchslop;
// 分别记录上次滑动的坐标
private int mlastx = 0;
private int mlasty = 0;
// 分别记录上次滑动的坐标(onintercepttouchenvent)
private int mlastxintercept = 0;
private int mlastyintercept = 0;
private scroller mscroller;
private velocitytracker mvelocitytracker;
private recyclerview.adapter madapter;
public recyclerview getrecyclerview() {
return mrecyclerview;
}
private recyclerview mrecyclerview;
private int default = 0;
private final int pull_down_refresh = 1;
private final int release_refresh = 2;
private final int refreshing = 3;
private final int load_more = 4;
private int state = default;
private int rfreshheaderwidth;
private int refreshheadviewheight;
private onpulllistener monpulllistener;
private view mrefreshheaderview;
private recyclerview.layoutmanager mlayoutmanager;
int refreshheadviewid;
public void setlayoutmanager(recyclerview.layoutmanager manager) {
this.mlayoutmanager = manager;
mrecyclerview.setlayoutmanager(mlayoutmanager);
}
public void setadapter(recyclerview.adapter adapter) {
this.madapter = adapter;
mrecyclerview.setadapter(madapter);
}
public view getrefreshheaderview() {
return mrefreshheaderview;
}
public void setonpullshowviewlistener(onpullshowviewlistener onpullshowviewlistener) {
monpullshowviewlistener = onpullshowviewlistener;
}
private onpullshowviewlistener monpullshowviewlistener;
public void setonpulllistener(onpulllistener onpulllistener) {
monpulllistener = onpulllistener;
}
public realpullrefreshview(context context) {
super(context);
initview(context);
}
public realpullrefreshview(context context, @nullable attributeset attrs) {
super(context, attrs);
initattrs(context, attrs);
// ★★★★★一个坑initattrs方法里的typedarray去获取属性时，第一次获取的属性全是0，他会马上重走一次构造方法，再次获取一次，才能获得正确的值
// 如果第一次获取的值为0，则不去initview
if (refreshheadviewid != 0) {
initview(context);
}
}
public realpullrefreshview(context context, @nullable attributeset attrs, int defstyleattr) {
super(context, attrs, defstyleattr);
initattrs(context, attrs);
if (refreshheadviewid != 0) {
initview(context);
}
}
private void initattrs(context context, attributeset attrs) {
typedarray typedarray = context.obtainstyledattributes(attrs, r.styleable.realpullrefreshview);
try {
refreshheadviewid = typedarray.getresourceid(r.styleable.realpullrefreshview_refresh_header_view, 0);
} finally {
typedarray.recycle();
}
}
private void initview(context context) {
mscroller = new scroller(getcontext());
mvelocitytracker = velocitytracker.obtain();
// 添加headerview
// ★ ★ ★ ★ ★ 注意不要用这个方法inflate布局，会导致layout的所有属性失效，height、width、margin
// 原因见 http://blog.csdn.net/zhaokaiqiang1992/article/details/36006467
// ★ ★ ★ ★ ★ mrefreshheaderview = minflater.inflate(r.layout.headerview, null);
mrefreshheaderview = layoutinflater.from(context).inflate(refreshheadviewid, this, false);
addview(mrefreshheaderview);
// }
// 以下代码主要是为了设置头布局的margintop值为-headerviewheight
// 注意必须等到一小会才会得到正确的头布局宽高
postdelayed(new runnable() {
@override
public void run() {
log.e("q11", refreshheadviewheight + "qqqqqqqqqq " + mrefreshheaderview.getheight());
rfreshheaderwidth = mrefreshheaderview.getwidth();
refreshheadviewheight = mrefreshheaderview.getheight();
marginlayoutparams lp = new linearlayout.layoutparams(rfreshheaderwidth, refreshheadviewheight);
lp.setmargins(0, -refreshheadviewheight, 0, 0);
mrefreshheaderview.setlayoutparams(lp);
}
}, 100);
// 添加recyclerview
mrecyclerview = new recyclerview(context);
addview(mrecyclerview, layoutparams.match_parent, viewgroup.layoutparams.match_parent);
// 这里我提供了一个默认的显示效果，如果用户不使用mrealpullrefreshview.setonpullshowviewlistener的话，会默认使用这个
// 用户可以实现onpullshowviewlistener接口，去实现自己想要的显示效果
monpullshowviewlistener = new implonpullshowviewlistener(this);
setloadmore();
}
private void setloadmore() {
// 当目前的可见条目是所有数据的最后一个时，开始加载新的数据
mrecyclerview.addonscrolllistener(new recyclerview.onscrolllistener() {
@override
public void onscrolled(recyclerview recyclerview, int dx, int dy) {
super.onscrolled(recyclerview, dx, dy);
int lastcompletelyvisibleitemposition = -1;
if (mlayoutmanager instanceof linearlayoutmanager) {
linearlayoutmanager manager = (linearlayoutmanager) mlayoutmanager;
lastcompletelyvisibleitemposition = manager.findlastvisibleitemposition();
} else if (mlayoutmanager instanceof gridlayoutmanager) {
gridlayoutmanager manager = (gridlayoutmanager) mlayoutmanager;
lastcompletelyvisibleitemposition = manager.findlastvisibleitemposition();
} else if (mlayoutmanager instanceof staggeredgridlayoutmanager) {
staggeredgridlayoutmanager manager = (staggeredgridlayoutmanager) mlayoutmanager;
lastcompletelyvisibleitemposition = manager.findlastvisibleitempositions(new int[manager.getspancount()])[0];
}
if (lastcompletelyvisibleitemposition + 1 == madapter.getitemcount()) {
if (monpulllistener != null && state == default) {
state = load_more;
monpulllistener.onloadmore();
}
}
}
});
}
@override
public boolean onintercepttouchevent(motionevent event) {
boolean intercepted = false;
int x = (int) event.getx();
int y = (int) event.gety();
switch (event.getaction()) {
case motionevent.action_down: {
intercepted = false;
/*if (state!=default||state!=refreshing){
if (!mscroller.isfinished()) {
mscroller.abortanimation();
}}*/
break;
}
case motionevent.action_move: {
int deltax = x - mlastxintercept;
int deltay = y - mlastyintercept;
int firstcompletelyvisibleitemposition = -1;
if (mlayoutmanager instanceof linearlayoutmanager) {
linearlayoutmanager manager = (linearlayoutmanager) mlayoutmanager;
firstcompletelyvisibleitemposition = manager.findfirstcompletelyvisibleitemposition();
} else if (mlayoutmanager instanceof gridlayoutmanager) {
gridlayoutmanager manager = (gridlayoutmanager) mlayoutmanager;
firstcompletelyvisibleitemposition = manager.findfirstcompletelyvisibleitemposition();
} else if (mlayoutmanager instanceof staggeredgridlayoutmanager) {
staggeredgridlayoutmanager manager = (staggeredgridlayoutmanager) mlayoutmanager;
firstcompletelyvisibleitemposition = manager.findfirstcompletelyvisibleitempositions(new int[manager.getspancount()])[0];
}
// ******************这里说明什么规则下，拦截，其余代码不要动了，其余代码指的是处理滑动冲突的代码***************
if (firstcompletelyvisibleitemposition == 0 && deltay > 0 && math.abs(deltay) > math.abs(deltax)) {//拉倒最顶部，继续往下拉，将拉出头布局，要父布局拦截
intercepted = true;
} else if (getscrolly() < 0) {//表示头布局已经向下拉出来，头布局已经显示了，要父布局拦截
intercepted = true;
} else if (deltay < 0) {
intercepted = false;//不要父布局拦截了
} else {
intercepted = false;//不要父布局拦截了
}
// ******************什么规则下，拦截***************
break;
}
case motionevent.action_up: {
intercepted = false;
break;
}
default:
break;
}
log.d(tag, "intercepted=" + intercepted);
mlastx = x;
mlasty = y;
mlastxintercept = x;
mlastyintercept = y;
return intercepted;
}
/**
* 下面不同布局，不同的滑动需求
*
* @param event
* @return
*/
@override
public boolean ontouchevent(motionevent event) {
mvelocitytracker.addmovement(event);
int x = (int) event.getx();
int y = (int) event.gety();
switch (event.getaction()) {
case motionevent.action_down: {
if (!mscroller.isfinished()) {
mscroller.abortanimation();
}
break;
}
case motionevent.action_move: {
int deltax = x - mlastx;
int deltay = y - mlasty;
if (getscrolly() > 0) {
//防止在正在刷新状态下，上拉出空白
} else if (getscrolly() <= 0 && getscrolly() > -refreshheadviewheight * 5) {
// 最多下拉到头布局高度5倍的距离
scrollby(0, -deltay / 2);
}
if (getscrolly() > -refreshheadviewheight && state != refreshing) {//头布局显示不全时，为下拉刷新pull_down_refresh状态
state = pull_down_refresh;
if (monpullshowviewlistener != null) {
monpullshowviewlistener.onpulldownrefreshstate(getscrolly(), refreshheadviewheight, deltay);
}
}
if (getscrolly() < -refreshheadviewheight && state != refreshing) {//头布局完全显示时，为释放刷新release_refresh状态
state = release_refresh;
if (monpullshowviewlistener != null) {
monpullshowviewlistener.onreleaserefreshstate(getscrolly(), deltay);
}
}
break;
}
case motionevent.action_up: {
final int scrolly = getscrolly();
//松手时，根据所处的状态，让布局滑动到不同的地方，做不同的操作
switch (state) {
case pull_down_refresh:
state = default;
//头布局没有完全显示，完全隐藏头布局
smoothscrollby(0, -scrolly);
break;
case release_refresh:
state = refreshing;
smoothscrollby(0, -refreshheadviewheight - scrolly);
if (monpullshowviewlistener != null) {
monpullshowviewlistener.onrefreshingstate();
}
if (monpulllistener != null) {
monpulllistener.onrefresh();
}
break;
case refreshing:
if (getscrolly() < -refreshheadviewheight) {
smoothscrollby(0, -refreshheadviewheight - scrolly);
} else {
smoothscrollby(0, -scrolly);
}
break;
}
mvelocitytracker.clear();
break;
}
default:
break;
}
mlastx = x;
mlasty = y;
return true;
}
/**
* 当用户使用完下拉刷新回调时，需要调用此方法，将头不去隐藏，将state恢复
*/
public void refreshfinish() {
smoothscrollby(0, 0 - getscrolly());
getrecyclerview().getadapter().notifydatasetchanged();
state = default;
if (monpullshowviewlistener != null) {
monpullshowviewlistener.ondefaultstate();
}
toast.maketext(getcontext(), "刷新成功!", toast.length_short).show();
}
/**
* 当用户使用完加载更多后回调时，需要调用此方法，将state恢复
*/
public void loadmrefinish() {
getrecyclerview().getadapter().notifydatasetchanged();
state = default;
toast.maketext(getcontext(), "加载成功了!", toast.length_short).show();
}
/**
* 在500毫秒内平滑地滚动多少像素点
*
* @param dx
* @param dy
*/
private void smoothscrollby(int dx, int dy) {
mscroller.startscroll(0, getscrolly(), 0, dy, 500);
invalidate();
}
@override
public void computescroll() {
if (mscroller.computescrolloffset()) {
scrollto(mscroller.getcurrx(), mscroller.getcurry());
postinvalidate();
}
}
/**
* 释放资源
*/
@override
protected void ondetachedfromwindow() {
mvelocitytracker.recycle();
super.ondetachedfromwindow();
}
// ***************
// *****************
/**
* 回调接口
*/
public interface onpulllistener {
/**
* 当下拉刷新正在刷新时，这时候可以去请求数据，记得最后调用refreshfinish()复位
*/
void onrefresh();
/**
* 当加载更多时
*/
void onloadmore();
}
/**
* 回调接口，可以通过下面的回调，自定义各种状态下的显示效果
* 可以根据下拉距离scrolly设计动画效果
*/
public interface onpullshowviewlistener {
/**
* 当处于下拉刷新时，头布局显示效果
*
* @param scrolly 下拉的距离
* @param headviewheight 头布局高度
* @param deltay movey-lastmovey,正值为向下拉
*/
void onpulldownrefreshstate(int scrolly, int headviewheight, int deltay);
/**
* 当处于松手刷新时，头布局显示效果
*
* @param scrolly 下拉的距离
* @param deltay movey-lastmovey,正值为向下拉
*/
void onreleaserefreshstate(int scrolly, int deltay);
/**
* 正在刷新时，页面的显示效果
*/
void onrefreshingstate();
/**
* 默认状态时，页面显示效果，主要是为了复位各种状态
*/
void ondefaultstate();
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。