Android刷新加载框架详解

2023-09-19 13:29:05 47

本文实例为大家分享了Android刷新加载框架的具体代码，供大家参考，具体内容如下

1.定义一个接口控制下拉和上拉

publicinterfacePullable{

/**
*是否可下拉
*/
booleancanPullDown();

/**
*是否可上拉
*/
booleancanPullUp();
}

2.定义一个刷新加载布局

publicclassPullToRefreshLayoutextendsRelativeLayout{

/**
*头
*/
privateViewheadView;//头视图
privateImageViewheadIv;//头图标
privateTextViewheadTv;//头文字
privateintheadHeight;//头高度
privatefloatheadBorder;//头临界
/**
*拉
*/
privateViewpullView;//拉视图
privateintpullHeight;//拉高度
privateintpullWidth;//拉宽度

/**
*尾
*/
privateViewfootView;//尾视图
privateImageViewfootIv;//尾图标
privateTextViewfootTv;//尾文字
privateintfootHeight;//尾高度
privatefloatfootBorder;//尾临界

/**
*状态
*/
publicstaticfinalintINIT=0;//初始
publicstaticfinalintRELEASE_TO_REFRESH=1;//释放刷新
publicstaticfinalintREFRESHING=2;//正在刷新
publicstaticfinalintRELEASE_TO_LOAD=3;//释放加载
publicstaticfinalintLOADING=4;//正在加载
publicstaticfinalintDONE=5;//完成
privateintstate=INIT;

/**
*接口
*/
privateOnRefreshListenermListener;

privatefloatdownY;//按下时Y坐标
privatefloatlastY;//上一个Y坐标
privatefloatpullDownY=0;//下拉偏移量
privatefloatpullUpY=0;//上拉偏移量
privateintoffset;//偏移量

/**
*动画
*/
privateRotateAnimationrotateAnimation;

/**
*线程
*/
privateHandlerhandler=newHandler(){
@Override
publicvoidhandleMessage(Messagemsg){
super.handleMessage(msg);
if(msg!=null){
switch(msg.what){
case1:
headIv.clearAnimation();
break;
case2:
footIv.clearAnimation();
break;
default:
break;
}
pullDownY=0;
pullUpY=0;
requestLayout();
state=INIT;
refreshViewByState();
isTouch=true;
}
}
};

/**
*第一次执行布局
*/
privatebooleanisLayout=false;
/**
*在刷新过程中滑动操作
*/
privatebooleanisTouch=false;
/**
*手指滑动距离与下拉头的滑动距离比，中间会随正切函数变化
*/
privatefloatradio=2;
/**
*过滤多点触碰
*/
privateintmEvents;
/**
*这两个变量用来控制pull的方向，如果不加控制，当情况满足可上拉又可下拉时没法下拉
*/
privatebooleancanPullDown=true;
privatebooleancanPullUp=true;

publicvoidsetOnRefreshListener(OnRefreshListenerlistener){
mListener=listener;
}

publicPullToRefreshLayout(Contextcontext){
super(context);
initView(context);
}

publicPullToRefreshLayout(Contextcontext,AttributeSetattrs){
super(context,attrs);
initView(context);
}

publicPullToRefreshLayout(Contextcontext,AttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
initView(context);
}

privatevoidinitView(Contextcontext){
rotateAnimation=(RotateAnimation)AnimationUtils.loadAnimation(context,R.anim.rotating);
}

privatevoidrefreshViewByState(){
switch(state){
caseINIT:
//下拉布局初始状态
headIv.setImageResource("下拉刷新显示的图片");
headTv.setText("下拉刷新");
//上拉布局初始状态
footIv.setImageResource("上拉加载显示的图片");
footTv.setText("上拉加载");
break;
caseRELEASE_TO_REFRESH:
//释放刷新状态
headIv.setImageResource("释放刷新显示的图片");
headTv.setText("释放刷新");
break;
caseREFRESHING:
//正在刷新状态
headIv.setImageResource("正在刷新显示的图片");
headTv.setText("正在刷新");
break;
caseRELEASE_TO_LOAD:
//释放加载状态
footIv.setImageResource("释放加载显示的图片");
footTv.setText("释放加载");
break;
caseLOADING:
//正在加载状态
footIv.setImageResource("正在加载显示的图片");
footTv.setText("正在加载");
break;
caseDONE:
//刷新或加载完毕，啥都不做
break;
}
}

/**
*不限制上拉或下拉
*/
privatevoidreleasePull(){
canPullDown=true;
canPullUp=true;
}

@Override
publicbooleandispatchTouchEvent(MotionEventev){
switch(ev.getActionMasked()){
caseMotionEvent.ACTION_DOWN:
downY=ev.getY();
lastY=downY;
mEvents=0;
releasePull();
if(state!=REFRESHING&&state!=LOADING){
isTouch=true;
}
break;
caseMotionEvent.ACTION_POINTER_DOWN:
caseMotionEvent.ACTION_POINTER_UP:
//过滤多点触碰
mEvents=-1;
break;
caseMotionEvent.ACTION_MOVE:
if(mEvents==0){
if(pullDownY>0||(((Pullable)pullView).canPullDown()
&&canPullDown&&state!=LOADING&&state!=REFRESHING)){
//可以下拉，正在加载时不能下拉
//对实际滑动距离做缩小，造成用力拉的感觉
pullDownY=pullDownY+(ev.getY()-lastY)/radio;
if(pullDownY<0){
pullDownY=0;
canPullDown=false;
canPullUp=true;
}
if(pullDownY>getMeasuredHeight()){
pullDownY=getMeasuredHeight();
}
if(state==REFRESHING){
//正在刷新的时候触摸移动
isTouch=false;
}
}elseif(pullUpY<0
||(((Pullable)pullView).canPullUp()&&canPullUp&&state!=REFRESHING&&state!=LOADING)){
//可以上拉，正在刷新时不能上拉
pullUpY=pullUpY+(ev.getY()-lastY)/radio;

if(pullUpY>0){
pullUpY=0;
canPullDown=true;
canPullUp=false;
}
if(pullUpY<-getMeasuredHeight()){
pullUpY=-getMeasuredHeight();
}
if(state==LOADING){
//正在加载的时候触摸移动
isTouch=false;
}
}
}
if(isTouch){
lastY=ev.getY();
if(pullDownY>0||pullUpY<0){
requestLayout();
}
if(pullDownY>0){
if(pullDownY<=headBorder&&(state==RELEASE_TO_REFRESH||state==DONE)){
//如果下拉距离没达到刷新的距离且当前状态是释放刷新，改变状态为下拉刷新
state=INIT;
refreshViewByState();
}
if(pullDownY>=headBorder&&state==INIT){
//如果下拉距离达到刷新的距离且当前状态是初始状态刷新，改变状态为释放刷新
state=RELEASE_TO_REFRESH;
refreshViewByState();
}
}elseif(pullUpY<0){
//下面是判断上拉加载的，同上，注意pullUpY是负值
if(-pullUpY<=footBorder&&(state==RELEASE_TO_LOAD||state==DONE)){
state=INIT;
refreshViewByState();
}
//上拉操作
if(-pullUpY>=footBorder&&state==INIT){
state=RELEASE_TO_LOAD;
refreshViewByState();
}
}
//因为刷新和加载操作不能同时进行，所以pullDownY和pullUpY不会同时不为0，因此这里用(pullDownY+
//Math.abs(pullUpY))就可以不对当前状态作区分了
if((pullDownY+Math.abs(pullUpY))>8){
//防止下拉过程中误触发长按事件和点击事件
ev.setAction(MotionEvent.ACTION_CANCEL);
}
}
break;
caseMotionEvent.ACTION_UP:
if(pullDownY>headBorder||-pullUpY>footBorder){
//正在刷新时往下拉（正在加载时往上拉），释放后下拉头（上拉头）不隐藏
isTouch=false;
}
if(state==RELEASE_TO_REFRESH){
state=REFRESHING;
refreshViewByState();
//刷新操作
if(mListener!=null){
canPullDown=false;
pullDownY=headBorder;
pullUpY=0;
requestLayout();
headIv.startAnimation(rotateAnimation);
mListener.onRefresh(this);
}
}elseif(state==RELEASE_TO_LOAD){
state=LOADING;
refreshViewByState();
//加载操作
if(mListener!=null){
canPullUp=false;
pullDownY=0;
pullUpY=-footBorder;
requestLayout();
footIv.startAnimation(rotateAnimation);
mListener.onLoadMore(this);
}
}else{
pullDownY=0;
pullUpY=0;
requestLayout();
}
default:
break;
}
//事件分发交给父类
super.dispatchTouchEvent(ev);
returntrue;
}

publicvoidhideHeadView(){
handler.sendEmptyMessage(1);
}

publicvoidhideFootView(){
handler.sendEmptyMessage(2);
}

privatevoidinitView(){
//初始化下拉布局
headIv=(ImageView)headView.findViewById(R.id.iv_head);
headTv=(TextView)headView.findViewById(R.id.tv_head);
//初始化上拉布局
footIv=(ImageView)footView.findViewById(R.id.iv_foot);
footTv=(TextView)footView.findViewById(R.id.tv_foot);
refreshViewByState();
}

@Override
protectedvoidonLayout(booleanchanged,intl,intt,intr,intb){
if(!isLayout){
//这里是第一次进来的时候做一些初始化
headView=getChildAt(0);
pullView=getChildAt(1);
footView=getChildAt(2);
headBorder=((ViewGroup)headView).getChildAt(0).getMeasuredHeight();
footBorder=((ViewGroup)footView).getChildAt(0).getMeasuredHeight();
headHeight=headView.getMeasuredHeight();
pullHeight=pullView.getMeasuredHeight();
footHeight=footView.getMeasuredHeight();
pullWidth=pullView.getMeasuredWidth();
initView();
isLayout=true;
}
//改变子控件的布局，这里直接用(pullDownY+pullUpY)作为偏移量，这样就可以不对当前状态作区分
offset=(int)(pullDownY+pullUpY);
headView.layout(0,-headHeight+offset,pullWidth,offset);
pullView.layout(0,offset,pullWidth,pullHeight+offset);
footView.layout(0,pullHeight+offset,pullWidth,pullHeight+footHeight+offset);
}

publicinterfaceOnRefreshListener{
voidonRefresh(PullToRefreshLayoutpullToRefreshLayout);

voidonLoadMore(PullToRefreshLayoutpullToRefreshLayout);
}

}

3.自定义View
ListView

publicclassPullableListViewextendsListViewimplementsPullable{

publicPullableListView(Contextcontext){
super(context);
}

publicPullableListView(Contextcontext,AttributeSetattrs){
super(context,attrs);
}

publicPullableListView(Contextcontext,AttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown(){
if(getCount()==0){
//没有item的时候也可以下拉刷新
returnfalse;
}elseif(getFirstVisiblePosition()==0&&getChildAt(0).getTop()>=0){
//滑到ListView的顶部了
returntrue;
}else
returnfalse;
}

@Override
publicbooleancanPullUp(){
if(getCount()==0){
//没有item的时候也可以上拉加载
returnfalse;
}elseif(getLastVisiblePosition()==(getCount()-1)){
//滑到底部了
if(getChildAt(getLastVisiblePosition()-getFirstVisiblePosition())!=null
&&getChildAt(getLastVisiblePosition()-getFirstVisiblePosition())
.getBottom()<=getMeasuredHeight())
returntrue;
}
returnfalse;
}
}

GridView

publicclassPullableGridViewextendsGridViewimplementsPullable{

publicPullableGridView(Contextcontext){
super(context);
}

publicPullableGridView(Contextcontext,AttributeSetattrs){
super(context,attrs);
}

publicPullableGridView(Contextcontext,AttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown(){
if(getCount()==0){
//没有item的时候也可以下拉刷新
returnfalse;
}elseif(getFirstVisiblePosition()==0
&&getChildAt(0).getTop()>=0){
//滑到顶部了
returntrue;
}else
returnfalse;
}

@Override
publicbooleancanPullUp(){
if(getCount()==0){
//没有item的时候也可以上拉加载
returnfalse;
}elseif(getLastVisiblePosition()==(getCount()-1)){
//滑到底部了
if(getChildAt(getLastVisiblePosition()-getFirstVisiblePosition())!=null
&&getChildAt(
getLastVisiblePosition()
-getFirstVisiblePosition()).getBottom()<=getMeasuredHeight())
returntrue;
}
returnfalse;
}

}

RecyclerView

publicclassPullableRecyclerViewextendsRecyclerViewimplementsPullable{

publicPullableRecyclerView(Contextcontext){
super(context);
}

publicPullableRecyclerView(Contextcontext,@NullableAttributeSetattrs){
super(context,attrs);
}

publicPullableRecyclerView(Contextcontext,@NullableAttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown(){
RecyclerView.LayoutManagerlayoutManager=getLayoutManager();
if(layoutManagerinstanceofLinearLayoutManager){
LinearLayoutManagerlinearLayoutManager=(LinearLayoutManager)layoutManager;
if(linearLayoutManager.getItemCount()==0){
returnfalse;
}elseif(linearLayoutManager.findFirstVisibleItemPosition()==0&&linearLayoutManager.getChildAt(0).getTop()>=0){
returntrue;
}else{
returnfalse;
}
}elseif(layoutManagerinstanceofStaggeredGridLayoutManager){
StaggeredGridLayoutManagerstaggeredGridLayoutManager=(StaggeredGridLayoutManager)layoutManager;
if(staggeredGridLayoutManager.getItemCount()==0){
returnfalse;
}else{
int[]firstVisibleItems=null;
firstVisibleItems=staggeredGridLayoutManager.findFirstVisibleItemPositions(firstVisibleItems);
if(firstVisibleItems!=null&&firstVisibleItems.length>0){
if(staggeredGridLayoutManager.getChildCount()+firstVisibleItems[0]==staggeredGridLayoutManager.getItemCount()){
returntrue;
}
}
}
}
returnfalse;
}

@Override
publicbooleancanPullUp(){
RecyclerView.LayoutManagerlayoutManager=getLayoutManager();
if(layoutManagerinstanceofLinearLayoutManager){
LinearLayoutManagerlinearLayoutManager=(LinearLayoutManager)layoutManager;
if(linearLayoutManager.getItemCount()==0){
returnfalse;
}elseif(linearLayoutManager.findLastVisibleItemPosition()==(linearLayoutManager.getItemCount()-1)){
if(linearLayoutManager.getChildAt(linearLayoutManager.findLastVisibleItemPosition()-linearLayoutManager.findFirstVisibleItemPosition())!=null
&&linearLayoutManager.getChildAt(linearLayoutManager.findLastVisibleItemPosition()-linearLayoutManager.findFirstVisibleItemPosition()).getBottom()<=getMeasuredHeight()){
returntrue;
}
}
}elseif(layoutManagerinstanceofStaggeredGridLayoutManager){
StaggeredGridLayoutManagerstaggeredGridLayoutManager=(StaggeredGridLayoutManager)layoutManager;
if(staggeredGridLayoutManager.getItemCount()==0){
returnfalse;
}else{
int[]lastPositions=newint[staggeredGridLayoutManager.getSpanCount()];
lastPositions=staggeredGridLayoutManager.findLastVisibleItemPositions(lastPositions);
if(findMax(lastPositions)>=staggeredGridLayoutManager.getItemCount()-1){
returntrue;
}
}
}
returnfalse;
}

privateintfindMax(int[]lastPositions){
intmax=lastPositions[0];
for(intvalue:lastPositions){
if(value>max){
max=value;
}
}
returnmax;
}
}

ExpandableListView

publicclassPullableExpandableListViewextendsExpandableListViewimplements
Pullable{

publicPullableExpandableListView(Contextcontext){
super(context);
}

publicPullableExpandableListView(Contextcontext,AttributeSetattrs){
super(context,attrs);
}

publicPullableExpandableListView(Contextcontext,AttributeSetattrs,
intdefStyle){
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown(){
if(getCount()==0){
//没有item的时候也可以下拉刷新
returnfalse;
}elseif(getFirstVisiblePosition()==0
&&getChildAt(0).getTop()>=0){
//滑到顶部了
returntrue;
}else
returnfalse;
}

@Override
publicbooleancanPullUp(){
if(getCount()==0){
//没有item的时候也可以上拉加载
returnfalse;
}elseif(getLastVisiblePosition()==(getCount()-1)){
//滑到底部了
if(getChildAt(getLastVisiblePosition()-getFirstVisiblePosition())!=null
&&getChildAt(
getLastVisiblePosition()
-getFirstVisiblePosition()).getBottom()<=getMeasuredHeight())
returntrue;
}
returnfalse;
}

}

ScrollView

publicclassPullableScrollViewextendsScrollViewimplementsPullable{

publicPullableScrollView(Contextcontext){
super(context);
}

publicPullableScrollView(Contextcontext,AttributeSetattrs){
super(context,attrs);
}

publicPullableScrollView(Contextcontext,AttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown(){
if(getScrollY()==0)
returntrue;
else
returnfalse;
}

@Override
publicbooleancanPullUp(){
if(getScrollY()>=(getChildAt(0).getHeight()-getMeasuredHeight()))
returntrue;
else
returnfalse;
}

}

WebView

publicclassPullableWebViewextendsWebViewimplementsPullable{

publicPullableWebView(Contextcontext){
super(context);
}

publicPullableWebView(Contextcontext,AttributeSetattrs){
super(context,attrs);
}

publicPullableWebView(Contextcontext,AttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown(){
if(getScrollY()==0)
returntrue;
else
returnfalse;
}

@Override
publicbooleancanPullUp(){
if(getScrollY()>=getContentHeight()*getScale()
-getMeasuredHeight())
returntrue;
else
returnfalse;
}
}

ImageView

publicclassPullableImageViewextendsImageViewimplementsPullable
{

publicPullableImageView(Contextcontext)
{
super(context);
}

publicPullableImageView(Contextcontext,AttributeSetattrs)
{
super(context,attrs);
}

publicPullableImageView(Contextcontext,AttributeSetattrs,intdefStyle)
{
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown()
{
returntrue;
}

@Override
publicbooleancanPullUp()
{
returntrue;
}

}

TextView

publicclassPullableTextViewextendsTextViewimplementsPullable{

publicPullableTextView(Contextcontext){
super(context);
}

publicPullableTextView(Contextcontext,AttributeSetattrs){
super(context,attrs);
}

publicPullableTextView(Contextcontext,AttributeSetattrs,intdefStyle){
super(context,attrs,defStyle);
}

@Override
publicbooleancanPullDown(){
returntrue;
}

@Override
publicbooleancanPullUp(){
returntrue;
}

}

4.使用示例(以ListView为例)

head

foot

4.注意

自定义的View跟正常的View的使用没有什么差别
如需实现刷新加载，必须使ptrl.setOnRefreshListener(PullToRefreshLayout.OnRefreshListeneronRefreshListener);

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毛票票。

Android刷新加载框架详解

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