Android ListView下拉刷新上拉自动加载更多DEMO示例

代码下载地址已经更新。因为代码很久没更新，已经很落伍了，建议大家使用recyclerview实现。

参考项目：

https://github.com/bingoogolapple/bgarefreshlayout-android

https://github.com/baoyongzhang/android-pullrefreshlayout

下拉刷新，android中非常普遍的功能。为了方便便重写的listview来实现下拉刷新，同时添加了上拉自动加载更多的功能。设计最初是参考开源中国的android客户端源码。先看示例图。

图1 图2

图3 图4

图5 图6

下拉刷新的时动画效果: 图1 ==》 图2 ==》 图3 ==》 图4 ==》 图1。

上拉自动加载更多的效果：图5

图6是示例demo的截图

重写后的listview动画效果来源于添加的头部（header）和尾部（footer），listview提供了addheaderview和addfooterview方法来添加header和footer。大家也可以通过修改头部、尾部的xml文件来定义自己的动画效果。

实现原理

1.下拉刷新

通过ontouchevent判断手势，来改变listview的header。header的状态共4种，自己定义为：

none（对应图1）：初始状态

pull（对应图2）：下拉状态，此时松开会还原到状态none，并不进行刷新

release（对应图3）：同样是下拉状态，但此刻松开会执行刷新，进入状态refreshing

refreshing（对应图4）：正在执行刷新，刷新结束后进入状态none。

header在四种状态切换时不仅改变内部组件，同时改变自身的大小。改变内部组件的体现比如，箭头的朝上或者朝下，文字提示的变化，等待圆圈的显示与否。大小的改变其实就是高度的改变，none时header高度为0,release时header的高度由你下拉的程度决定。

2.加载更多

在listview滑动停止后，判断listview的最后一个item是否已经显示，如果显示说明listview已经滑动到了最底部，这时便触发加载更多的方法，方法结束根据结果改变footer。

3.回调方法

在类中定义了两个接口onrefreshlistener和onloadlistener，用来定义和提供加载数据的方法，具体实现则交给它们的实现类去做。

package com.example.autolistview.widget; 
import com.example.autolistview.r; 
import com.example.autolistview.utils.utils; 
import android.content.context; 
import android.util.attributeset; 
import android.view.layoutinflater; 
import android.view.motionevent; 
import android.view.view; 
import android.view.viewgroup; 
import android.view.animation.linearinterpolator; 
import android.view.animation.rotateanimation; 
import android.widget.abslistview; 
import android.widget.imageview; 
import android.widget.progressbar; 
import android.widget.textview; 
import android.widget.abslistview.onscrolllistener; 
import android.widget.listview; 
/** 
* @author sunnycoffee 
* @create 2013-10-24 
* @version 1.0 
* @desc 自定义listview　下拉刷新,上拉加载更多 
*/ 
public class autolistview extends listview implements onscrolllistener { 
// 区分当前操作是刷新还是加载 
public static final int refresh = 0; 
public static final int load = 1; 
// 区分pull和release的距离的大小 
private static final int space = 20; 
// 定义header的四种状态和当前状态 
private static final int none = 0; 
private static final int pull = 1; 
private static final int release = 2; 
private static final int refreshing = 3; 
private int state; 
private layoutinflater inflater; 
private view header; 
private view footer; 
private textview tip; 
private textview lastupdate; 
private imageview arrow; 
private progressbar refreshing; 
private textview nodata; 
private textview loadfull; 
private textview more; 
private progressbar loading; 
private rotateanimation animation; 
private rotateanimation reverseanimation; 
private int starty; 
private int firstvisibleitem; 
private int scrollstate; 
private int headercontentinitialheight; 
private int headercontentheight; 
// 只有在listview第一个item显示的时候（listview滑到了顶部）才进行下拉刷新， 否则此时的下拉只是滑动listview 
private boolean isrecorded; 
private boolean isloading;// 判断是否正在加载 
private boolean loadenable = true;// 开启或者关闭加载更多功能 
private boolean isloadfull; 
private int pagesize = 10; 
private onrefreshlistener onrefreshlistener; 
private onloadlistener onloadlistener; 
public autolistview(context context) { 
super(context); 
initview(context); 
} 
public autolistview(context context, attributeset attrs) { 
super(context, attrs); 
initview(context); 
} 
public autolistview(context context, attributeset attrs, int defstyle) { 
super(context, attrs, defstyle); 
initview(context); 
} 
// 下拉刷新监听 
public void setonrefreshlistener(onrefreshlistener onrefreshlistener) { 
this.onrefreshlistener = onrefreshlistener; 
} 
// 加载更多监听 
public void setonloadlistener(onloadlistener onloadlistener) { 
this.loadenable = true; 
this.onloadlistener = onloadlistener; 
} 
public boolean isloadenable() { 
return loadenable; 
} 
// 这里的开启或者关闭加载更多，并不支持动态调整 
public void setloadenable(boolean loadenable) { 
this.loadenable = loadenable; 
this.removefooterview(footer); 
} 
public int getpagesize() { 
return pagesize; 
} 
public void setpagesize(int pagesize) { 
this.pagesize = pagesize; 
} 
// 初始化组件 
private void initview(context context) { 
// 设置箭头特效 
animation = new rotateanimation(0, -180, 
rotateanimation.relative_to_self, 0.5f, 
rotateanimation.relative_to_self, 0.5f); 
animation.setinterpolator(new linearinterpolator()); 
animation.setduration(100); 
animation.setfillafter(true); 
reverseanimation = new rotateanimation(-180, 0, 
rotateanimation.relative_to_self, 0.5f, 
rotateanimation.relative_to_self, 0.5f); 
reverseanimation.setinterpolator(new linearinterpolator()); 
reverseanimation.setduration(100); 
reverseanimation.setfillafter(true); 
inflater = layoutinflater.from(context); 
footer = inflater.inflate(r.layout.listview_footer, null); 
loadfull = (textview) footer.findviewbyid(r.id.loadfull); 
nodata = (textview) footer.findviewbyid(r.id.nodata); 
more = (textview) footer.findviewbyid(r.id.more); 
loading = (progressbar) footer.findviewbyid(r.id.loading); 
header = inflater.inflate(r.layout.pull_to_refresh_header, null); 
arrow = (imageview) header.findviewbyid(r.id.arrow); 
tip = (textview) header.findviewbyid(r.id.tip); 
lastupdate = (textview) header.findviewbyid(r.id.lastupdate); 
refreshing = (progressbar) header.findviewbyid(r.id.refreshing); 
// 为listview添加头部和尾部，并进行初始化 
headercontentinitialheight = header.getpaddingtop(); 
measureview(header); 
headercontentheight = header.getmeasuredheight(); 
toppadding(-headercontentheight); 
this.addheaderview(header); 
this.addfooterview(footer); 
this.setonscrolllistener(this); 
} 
public void onrefresh() { 
if (onrefreshlistener != null) { 
onrefreshlistener.onrefresh(); 
} 
} 
public void onload() { 
if (onloadlistener != null) { 
onloadlistener.onload(); 
} 
} 
public void onrefreshcomplete(string updatetime) { 
lastupdate.settext(this.getcontext().getstring(r.string.lastupdatetime, 
lastupdate)); 
state = none; 
refreshheaderviewbystate(); 
} 
// 用于下拉刷新结束后的回调 
public void onrefreshcomplete() { 
string currenttime = utils.getcurrenttime(); 
onrefreshcomplete(currenttime); 
} 
// 用于加载更多结束后的回调 
public void onloadcomplete() { 
isloading = false; 
} 
@override 
public void onscroll(abslistview view, int firstvisibleitem, 
int visibleitemcount, int totalitemcount) { 
this.firstvisibleitem = firstvisibleitem; 
} 
@override 
public void onscrollstatechanged(abslistview view, int scrollstate) { 
this.scrollstate = scrollstate; 
ifneedload(view, scrollstate); 
} 
// 根据listview滑动的状态判断是否需要加载更多 
private void ifneedload(abslistview view, int scrollstate) { 
if (!loadenable) { 
return; 
} 
try { 
if (scrollstate == onscrolllistener.scroll_state_idle 
&& !isloading 
&& view.getlastvisibleposition() == view 
.getpositionforview(footer) && !isloadfull) { 
onload(); 
isloading = true; 
} 
} catch (exception e) { 
} 
} 
/** 
* 监听触摸事件，解读手势 
*/ 
@override 
public boolean ontouchevent(motionevent ev) { 
switch (ev.getaction()) { 
case motionevent.action_down: 
if (firstvisibleitem == 0) { 
isrecorded = true; 
starty = (int) ev.gety(); 
} 
break; 
case motionevent.action_cancel: 
case motionevent.action_up: 
if (state == pull) { 
state = none; 
refreshheaderviewbystate(); 
} else if (state == release) { 
state = refreshing; 
refreshheaderviewbystate(); 
onrefresh(); 
} 
isrecorded = false; 
break; 
case motionevent.action_move: 
whenmove(ev); 
break; 
} 
return super.ontouchevent(ev); 
} 
// 解读手势，刷新header状态 
private void whenmove(motionevent ev) { 
if (!isrecorded) { 
return; 
} 
int tmpy = (int) ev.gety(); 
int space = tmpy - starty; 
int toppadding = space - headercontentheight; 
switch (state) { 
case none: 
if (space > 0) { 
state = pull; 
refreshheaderviewbystate(); 
} 
break; 
case pull: 
toppadding(toppadding); 
if (scrollstate == scroll_state_touch_scroll 
&& space > headercontentheight + space) { 
state = release; 
refreshheaderviewbystate(); 
} 
break; 
case release: 
toppadding(toppadding); 
if (space > 0 && space < headercontentheight + space) { 
state = pull; 
refreshheaderviewbystate(); 
} else if (space <= 0) { 
state = none; 
refreshheaderviewbystate(); 
} 
break; 
} 
} 
// 调整header的大小。其实调整的只是距离顶部的高度。 
private void toppadding(int toppadding) { 
header.setpadding(header.getpaddingleft(), toppadding, 
header.getpaddingright(), header.getpaddingbottom()); 
header.invalidate(); 
} 
/** 
* 这个方法是根据结果的大小来决定footer显示的。 
* <p> 
* 这里假定每次请求的条数为10。如果请求到了10条。则认为还有数据。如过结果不足10条，则认为数据已经全部加载，这时footer显示已经全部加载 
* </p> 
* 
* @param resultsize 
*/ 
public void setresultsize(int resultsize) { 
if (resultsize == 0) { 
isloadfull = true; 
loadfull.setvisibility(view.gone); 
loading.setvisibility(view.gone); 
more.setvisibility(view.gone); 
nodata.setvisibility(view.visible); 
} else if (resultsize > 0 && resultsize < pagesize) { 
isloadfull = true; 
loadfull.setvisibility(view.visible); 
loading.setvisibility(view.gone); 
more.setvisibility(view.gone); 
nodata.setvisibility(view.gone); 
} else if (resultsize == pagesize) { 
isloadfull = false; 
loadfull.setvisibility(view.gone); 
loading.setvisibility(view.visible); 
more.setvisibility(view.visible); 
nodata.setvisibility(view.gone); 
} 
} 
// 根据当前状态，调整header 
private void refreshheaderviewbystate() { 
switch (state) { 
case none: 
toppadding(-headercontentheight); 
tip.settext(r.string.pull_to_refresh); 
refreshing.setvisibility(view.gone); 
arrow.clearanimation(); 
arrow.setimageresource(r.drawable.pull_to_refresh_arrow); 
break; 
case pull: 
arrow.setvisibility(view.visible); 
tip.setvisibility(view.visible); 
lastupdate.setvisibility(view.visible); 
refreshing.setvisibility(view.gone); 
tip.settext(r.string.pull_to_refresh); 
arrow.clearanimation(); 
arrow.setanimation(reverseanimation); 
break; 
case release: 
arrow.setvisibility(view.visible); 
tip.setvisibility(view.visible); 
lastupdate.setvisibility(view.visible); 
refreshing.setvisibility(view.gone); 
tip.settext(r.string.pull_to_refresh); 
tip.settext(r.string.release_to_refresh); 
arrow.clearanimation(); 
arrow.setanimation(animation); 
break; 
case refreshing: 
toppadding(headercontentinitialheight); 
refreshing.setvisibility(view.visible); 
arrow.clearanimation(); 
arrow.setvisibility(view.gone); 
tip.setvisibility(view.gone); 
lastupdate.setvisibility(view.gone); 
break; 
} 
} 
// 用来计算header大小的。比较隐晦。 
private void measureview(view child) { 
viewgroup.layoutparams p = child.getlayoutparams(); 
if (p == null) { 
p = new viewgroup.layoutparams(viewgroup.layoutparams.match_parent, 
viewgroup.layoutparams.wrap_content); 
} 
int childwidthspec = viewgroup.getchildmeasurespec(0, 0 + 0, p.width); 
int lpheight = p.height; 
int childheightspec; 
if (lpheight > 0) { 
childheightspec = measurespec.makemeasurespec(lpheight, 
measurespec.exactly); 
} else { 
childheightspec = measurespec.makemeasurespec(0, 
measurespec.unspecified); 
} 
child.measure(childwidthspec, childheightspec); 
} 
/* 
* 定义下拉刷新接口 
*/ 
public interface onrefreshlistener { 
public void onrefresh(); 
} 
/* 
* 定义加载更多接口 
*/ 
public interface onloadlistener { 
public void onload(); 
} 
}

这个类的逻辑复杂的地方就是header四种状态的判断和切换。

以下是几种状态的切换情况

none ==》 pull
none 《== pull ==》 release
pull 《== release ==》 refreshing
refreshing ==》 none

代码中对于 release ==》pull 状态的切换处理的不太理想，好像是纵坐标的记录方式有问题，如果有谁解决，希望能够留言告知。

为了减少篇幅，其他代码就不在贴了。

注意：定义header的xml最外层必须使用线性布局，不然的话会出错。

以上所述是小编给大家介绍的android listview下拉刷新上拉自动加载更多demo示例，希望对大家有所帮助